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• Rebiopolyols – new components. • New products characterized by a lower carbon footprint. • Chemolysis of polyurethane biofoams. • Polyurethane systems in which 100 % of the petrochemical polyol was replaced with new repolyols. The primary goal of the research presented here was to evaluate the possibility of chemolysis of polyurethane biofoams synthesized from vegetable oil-based biopolyols with different chemical structures. As a reference material, a foam synthesized in 100 % from a petrochemical polyol was used. Chemolysis of polyurethane foams was conducted by using diethylene glycol as a solvent with a 1.5:1 wt ratio of biopolyurethane scraps to glycol. The reaction was carried out at 180 °C for 100 min in the presence of potassium hydroxide as a catalyst. The results of the chemolysis of different polyurethane foams were evaluated in terms of the hydroxyl number, amine value, viscosity, molecular weight and FTIR analysis of the new rebiopolyols. It can be concluded that the chemical structures of different biopolyols (obtained through the method of transesterification of vegetable oils with two different reagents and a two-step method of epoxidation and oxirane rings opening) that are used to make biopolyurethane foams have an impact on the course of the chemolysis process and the properties of resultant rebiopolyols. In order to verify the application possibilities of the new components obtained in accordance with the idea of circular economy, extreme conditions were applied in the form of complete replacement of the polyol in the reference foam with the rebiopolyols. It was found that replacing the petrochemical polyol with the repolyol results in partial cell opening, and replacing this component with the rebiopolyols results in open-cell foams. Only the rebiopolyol derived from the biofoam with the biopolyol obtained by transesterification of oil with triethanolamine was not suitable for use in a polyurethane system because its reactivity was too high. In conclusion, there is no need to use catalysts to obtain new biofoams from rebiopolyols given the catalytic nature of the new biocomponents. [ABSTRACT FROM AUTHOR]

A bio-based and sweat-resistant polyurethane was designed for iontronic skin. With the incorporation of a stress concentration layer and serpentine-shaped electrodes, we achieved an iontronic skin with outstanding sensitivity, stability, and portability. This technology enables precise monitoring of respiratory states in CSA, potentially mitigating complications such as sudden death. [Display omitted] • This bio-based polyurethane integrated ion-trapping, biocompatibility and sweat-resistant functionalities. • The trap-release effect coupled with stress-concentration structure significantly enhances the sensitivity. • This iontronic skin could monitor various respiratory states to prevent sudden death. Central Sleep Apnea (CSA) is characterized by respiratory pauses during sleep, posing risks like cardiovascular diseases, stroke and sudden death. The challenges in managing it arise from the current monitoring tools, which are often complicated and inaccurate. Furthermore, respiratory pauses leading to decreased blood oxygen can induce profuse sweating, further affecting accuracy. Herein, we have synthesized a bio-based, biocompatible and sweat-resistant polyurethane. By utilizing it as the matrix, we incorporated [BMIM]+[PF 6 ]− to fabricate a markedly sensitive dielectric material, termed i-DFPU. The fluorine groups in i-DFPU contributed to a trap-release effect for migratable ions, while the alkyl side chains provided smooth ion migration channels, endowing i-DFPU with exceptional sensitivity. In combination with a stress concentration layer and serpentine-shaped electrodes, the resultant iontronic skin exhibited a remarkable sensitivity up to 132.2 kPa−1, operational stability and portability. Consequently, it could accurately monitor various respiratory states in CSA, potentially preventing complications such as sudden death. [ABSTRACT FROM AUTHOR]

• Long hard segment was constructed with ultrahigh thermal stability and cohesive energy. • Mechanical tough polyurethane with PDMS as the solely soft segment. • The resulted polyurethane was biocompatible and resistant to platelet adhesion. • Self-healing was realized in air, water and blood at ambient temperatures. Intravascular medical devices, like catheter, not only need to fulfill the challenge of biocompatibility but also be resistant to cracking or even breakage due to blood flushing and corrosion. Here, we synthesized polyurethanes with long hard segment for higher mechanical strength and effective self-healing in blood. In detail, Bis(trifluoromethyl)benzidine (TFMB) and dynamically linked 4-Aminophenyl disulfide (APS), and mixed diisocyanates of diisothiocyanate (PDITC) and hexamethylene diisocyanate (HMDI) were chosen to construct the long hard segment, which possesses hydrophobicity, dynamical bonds and a super strong hydrogen bonding interaction. For a selected sample, PU-4, which benefited from multi-hydrogen bonding, the degree of hydrogen bonding association kept as high as ∼ 97 % from 30 to 70 °C, and rheological testing proved that the hard domain and physical network are still stable at ∼ 115 °C. On the other hand, the surface content of Si is as high as 40 wt%, which not only endows the polymer with hydrophobicity but also a bioinert and antithrombotic surface. Consequently, the PU-4 showed a hemolysis rate of 0.4 %, an activated partial thromboplastin time of 50 s and free of platelet adhesion. By successfully screening complicate protein and ionic interactions with polymer chains, the self-healing of PU-4 in blood at 35 °C was realized, with mechanical strength recoverability up to 82 %. [ABSTRACT FROM AUTHOR]

• Addition of lignin as hard segment enhanced the physicomechanical properties of TPUs. • Lignin grafting of PCL enhanced the melt strength and foamability of TPUs. • Lignin hard segments in lieu of crosslinking provided shape memory while maintaining compostability. • The shape memory and foamable materials supported cell adhesion and growth for biomaterials. Biodegradable shape memory poly(e-caprolactone) (PCL)-based polyurethane (PU) have garnered substantial attention in biomedical applications, due to their unique properties that can recover their original shapes when exposed to temperature stimulus close to body temperature (∼35 °C). This study entails an in situ one-pot synthesis of a compostable shape memory PU system that uses PCL as soft chain segments, 1,4-butanediol (BDO) and glycerol (GLY) as chain extenders, which was then grafted with lignin hard segment and/or crosslinking nodes. The addition of renewable and sustainable lignin not only enhanced the mechanical properties of the PU, but also improved the resulting shape memory effects by increasing the shape fixing and recovery ratio. In PCL system containing BDO (PCL-BDO), 5 wt% lignin loading yields shape fixity and shape recovery ratios of 93.2 % and 81.4 %, respectively. Similarly, 5 wt% lignin in PCL systems containing GLY (PCL-GLY exhibited high shape fixity (64.4 %) and shape recovery ratio (81.4 %), respectively. Rheological characterizations showed strong evidence that the melt strength of both the PCL-BDO and PCL-GLY increased with the presence of lignin, which directly improved the physical foaming capabilities of PCL-based PU. The biocompatibility assessment also showed that the developed shape memory PCL-lignin based PU were not cytotoxic and capable of supporting cell adhesion and cell growth. [ABSTRACT FROM AUTHOR]

• Polyphenols with programmable hydrogen bonding are introduced into PUEs. • Programmable heat-induced strengthening effect was addressed. • Programmable UV-induced strengthening effect was addressed. • Unique selective biocompatibility to diverse microorganisms was addressed. Polyurethane elastomers address important significance in a wide range of applications. The mechanical properties including strength and toughness are of great importance, which are closely related to their unique hydrogen bonding structure. Unfortunately, the poor designability of hydrogen bonding structure in existing polyurethane severely restricts the on-demand regulation of their properties. Herein, a facile, universal and efficient modifying strategy based on stimuli-responsive polyphenol aggregates was proposed. Through precisely manipulated heat-induced aggregate division and/or photo-induced interfacial hydrogen bonding upgrading, programmable strengthening and toughening effect on the derived polyurethane elastomers could be achieved with high precision. Typically, the tensile strength and toughness of our proposed polyurethane elastomers could be enhanced by 3.23 and 2.22 times comparing with neat samples, respectively. The relevant results were supported by various characterizations and mathematical modeling. In addition, our polyurethane exhibited unique selective biocompatibility, rapid self-healing capability and recyclability, which could fulfill varieties of functions. Our proposed modifying strategy by using polyphenol aggregates can not only programmatically optimize the comprehensive properties of polyurethane, but also inspire programmable regulation of polymer performance through programmable design of its certain microstructure in the future. [ABSTRACT FROM AUTHOR]

• Polyurethane with fast self-healing capacity and excellent shape memory effect were synthesized. • The modulus and T g of polyurethane were regulated by the introduction of hindered phenols. • Smart skin-like wearable flexible photonic devices were prepared. • The flexible photonic device demonstrated superior stretchability and fast self-healing ability. Skin-like wearable devices have great potential in the era of intelligence. In addition to common electronic devices, flexible photonic devices are receiving ever-increasing attention, while intelligent features of devices such as self-healing are also requested. In this work, a smart skin-like wearable photonic device constructed by combining inorganic optical materials and self-healing polyurethanes is reported. Polyurethanes with skin-like modulus are synthesized by mixing chain extender, cross-linker, and hindered phenol AO-70, demonstrating fast self-healing capability (healing efficiency of 99 % within 2 min) and good shape memory effect (shape fixation rate of 90 %). A series of flexible photonic devices are prepared by depositing optical materials on polyurethane surfaces by physical vapor deposition (PVD), with a focus on a photonic device for 1064 nm laser protection. Notably, the device exhibits a spectral recovery rate of 91.76 % after 150 % strain and a spectral recovery rate of 98.13 % after healing in 2 min, indicating superior stretchability and fast self-healing ability. This work provides a new strategy for smart skin-like wearable flexible photonic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Cu2+ coordinated polyurethane (Cu-POU) with multiple functions were successfully prepared. • The Cu-POU is biocompatible, biodegradable, elastic and self-healing to meet the requirements of on-skin and implantable electronics and improve the stability and durability of resultant TENG. • The self-healing ability enables the assembly of an integrated TENG, as well as the preparation of sophisticated structure. Triboelectric nanogenerators (TENGs) have great potential as power sources for on-skin and implantable electronics. However, most existing TENGs are not suitable for the above applications due to limited material choices, often characterized by rigidity, susceptibility to damage, biological incompatibility, and non-biodegradability. Herein, we developed a simple self-healing assembly strategy based on introducing dynamic Cu(II)-dimethylglyoxime-urethane groups into a biocompatible and biodegradable polyurethane elastomer, to simultaneously address the above obstacles. The coordination of Cu2+ with dynamic bonds significantly enhanced the mechanical properties of elastomer, resulting in a modulus of 9.4 MPa and toughness of 40.2 MJ/m3. These bonds also gave the elastomer skin-like self-healing capabilities, achieving a healing efficiency of 77.5 % at 80 °C. Subsequently, a highly stretchable and integrated triboelectric nanogenerator (Cu-POU TENG) with self-healing capabilities was developed. The Cu-POU TENG with an effective area of 1.5 × 1.5 cm2 produced an open-circuit voltage of 38 V in single-electrode mode. The Cu-POU TENG could restore its original electrical properties through self-healing after mechanical damage. Furthermore, the Cu-POU TENG exhibited biocompatibility and biodegradability, making it suitable for on-skin and implantable electronics. Notably, the Cu-POU TENG maintained a stable voltage output throughout the degradation process. The integration of self-healing feature enabled a sophisticated structure, allowing the Cu-POU TENG to function effectively as a motion sensor for tracking body movement. This Cu-POU TENG holds great potential for applications in on-skin and implantable electronics. [ABSTRACT FROM AUTHOR]

3 wt% mini-sized graphene filled polyurethane exhibits improved 81% tensile strength and 126.7% modulus at an elongation of 605%, and 17 times thermal conductivity (4.24 W/m·K) over PU. There exist more hydrogen bonds and improved microphase separation of hard and soft segments for the reinforcement of polyurethane by mini-sized graphene. [Display omitted] • Graphene filler features small sheet size (300 × 400 nm) and low defects. • 3 wt% graphene filling polyurethane was optimized. • Improved 81% tensile strength, 126.7% modulus and 17 times thermal conductivity. • The reinforcement results from promoted microphase separation and hydrogen bonds. Graphene filler can improve certain properties of a polymer, but often compromises others, partially because it is difficult to control graphene size and dispersion at high content in polymer matrix. In this work, we present that mini-sized sheet sizes (300 × 400 nm) of graphene microsheets (mG) up to 7 wt% are filled in polyurethane (PU) reaching improved performances including mechanical properties (tensile strength, modulus, shape memory), electrical conductivity, thermal conductivity, thermal stability and flame retardance. The filling of 3 wt% mG in PU involves the enhancements of 81 % tensile strength (41.6 MPa at the elongation at break of 605 %), 126.7 % of modulus, 17 times of thermal conductivity (4.24 W/m·K) and 50℃ of thermal stability over net PU. The extensive characterizations disclose that hydrogen bonds strengthened and microphase separation promoted in the PU composite with the filling of the planar shape, hydrophilic edge and low defects of small graphene microsheets. This investigation presents a great potential of extending polymer materials with the filler of graphene microsheets derived from microcrystalline graphite minerals. [ABSTRACT FROM AUTHOR]

• Synthesized a novel polyurethane-based SPE system, named B x PU-Li y. • B 5 PU-Li 20 exhibits ionic conductivity of 3.28 × 10-5 S cm−1 at room temperature. • B 5 PU-Li 20 exhibits ionic conductivity of 2.0 × 10-4 S cm−1 at 40 °C. • Introduced naphthol to reduce crystallinity and enhance lithium ion transport. • Employed DFT computational simulations to explore intrinsic properties. In response to the demand for high-performance and safe batteries in the field of energy storage, a novel polyurethane-based solid electrolyte system, B x PU-Li y , has been developed. Crystallinity had been effectively reduced by incorporating 1,1′-binaphthol with a special molecular structure leading enhanced ion migration. Among that, B 5 PU-Li 20 demonstrates good mechanical properties and thermal stability, with an ionic conductivity of 3.28 × 10-5 S cm−1 at room temperature, increasing to 2.0 × 10-4 S cm−1 at 40 °C. Additionally, this material exhibits excellent electrochemical performance and battery cycling capabilities, offering a new direction for the development of high-performance battery technology, with potential applications in portable electronic devices, electric vehicles, and large-scale energy storage systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel bio-based diol containing imine dynamic bonds (Vanp2) were synthesized using vanillin and bio-based 1,5-pentanediamine. • Betulin-based polyurethane was synthesized containing covalent adaptive networks (CANs). • The polyurethane has excellent self-healing, re-processability and editable shape memory properties. • The betulin-based polyurethane could degrade totally in the acid solution. In this study, a novel bio-based diol containing imine dynamic bonds (Vanp2) were synthesized using vanillin and bio-based 1,5-pentanediamine. Vanp2 was then introduced into the cross-linking network of betulin-based polyurethanes to obtain betulin-based polyurethanes containing covalent adaptive networks (CANs). Imine dynamic bonds within CAN endowed these betulin-based polyurethanes with self-healing, re-processability, degradability, and editable shape memory functionalities. Meanwhile, the mechanical and thermal properties of these fully bio-based polyurethane materials were characterized. The maximum tensile strength reached 9.5 MPa, while the maximum strain at break was 248 % and the maximum toughness was 13.2 MJ/m3. Thermal decomposition temperature was greater than 300 °C. Since the imine structure could be dissociated under acidic conditions, these polyurethanes could be rapidly degraded in a mixed acid solution at 50 °C in 4 h. This study demonstrated a strategy for synthesizing betulin-based polyurethane elastomers containing CAN using only bio-based feedstock. [ABSTRACT FROM AUTHOR]

[Display omitted] • The mechanical properties of PU are designed by modulating hard segment contents. • Ballistic mechanism affected by matrix mechanical properties is studied thoroughly. • Ballistic mechanism is revealed by quasi-static tests, ballistic test and FE model. • Compared with hard/brittle matrix, soft/tough matrix are beneficial for ballistic performance. The matrix employed in the manufacture of composites significantly affects ballistic performances. However, the influence of mechanical properties of the matrix on ballistic mechanisms of composites has still not investigated thoroughly. Polyurethane, as a commonly used matrix, can be designed for various mechanical properties by modulating hard segment (HS) contents. In this work, polyurethanes with different HS contents (HS x -PUs) were prepared as matrix to investigate the ballistic mechanisms of the composites. The thermal and mechanical properties of the HS x -PUs were characterized. The HS x -PUs exhibited increases in the modulus and tensile strength but decreases in the elongation at break as the HS contents increased, and the mechanical properties transformed from soft and tough (HS 45 -PU and HS 55 -PU) to rigid and brittle (HS 65 -PU and HS 75 -PU). Moreover, quasi-static tests, ballistic test, and numerical simulation were integrated to explore the ballistic performances and mechanisms of aramid fabric reinforced HS x -PUs composites (HS x -PU/AF). The results revealed that the ballistic performances of HS x -PU/AF laminates exhibited an S-shaped growth trend as the HS content decreased. Compared with the HS 65 -PU/AF and HS 75 -PU/AF composites, the soft and tough HS 45 -PU and HS 55 -PU matrix can help to reduce delamination damage which can force more fibers to combine with each other, thus facilitating energy absorption of the composites. Moreover, the HS 45 -PU and HS 55 -PU matrix can reduce the modulus of the composites, which enabled matrix to deform with the fibres during penetration and improved the ballistic performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • FD-EPU with FrGO and DCOIT were successfully prepared. • FD-EPU had excellent resistance to cavitation. • FD-EPU had outstanding anticorrosion properties. • FD-EPU had excellent antibacterial and anti-algae functions. • FD-EPU showed distinguished self-healing properties under NIR light. Erosion and fouling are important factors that affect the performance of power components of large cargo ships. Inspired by animal cartilage tissue, an epoxy modified polyurethane composite coating (FD-EPU) with reproducible self-healing properties was successfully prepared. FD-EPU was endowed with excellent resistance to cavitation, corrosion, and fouling due to the presence of functional reduced graphene oxide (FrGO) and 2-octyl-4,5-dichloroisothiazolinone (DCOIT). The introduction of FrGO with multiple hydrogen bonds into coatings increased the tensile strength of FD-EPU by 3.56 MPa and exhibited excellent cavitation resistance (with a mass loss of 4.7 mg under continuous cavitation for 60 h). In addition, the barrier effect of FrGO enabled FD-EPU to possess outstanding anticorrosion ability. After being immersed in 3.5 wt% NaCl for a duration of 15 days, the |Z |0.01Hz value of FD-EPU was found to remain at 9.18 × 109 Ω·cm2. The modification of epoxy resulted in FD-EPU coatings with improved adhesion by 53.5 % compared to non-modified coatings, with a bond strength of 23.8 MPa on stainless steel. The incorporation of DCOIT and FrGO endowed FD-EPU with good antifouling properties (removal of more than 97.5 % of bacteria and removal rate of microalgae up to 96.2 %). Furthermore, FD-EPU exhibited outstanding opto-thermal self-healing capability, with a self-healing efficiency of 61 % after 30 s of near-infrared light irradiation. This work provides a new inspiration for the protection of large cargo ship power components. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developed an effective strategy to achieve high-strength self-healing elastomer. • The TA-modified MXene is self-assembled in the matrix to form a network structure. • MXene networks impart composites with efficient photothermal conversion efficiency. • The prepared flexible actuator can realize actions such as crawling and grabbing. Self-healing ability is highly desired for flexible actuators that operate in dynamic and real-world environments, as these machines are vulnerable to mechanical damage. However, self-healing properties and mechanical strength are often difficult to combine at the same time. We report a synergistic enhancement strategy based on the ordered micro-nano structure and interfacial hydrogen bonding aggregation to achieve self-healing elastomer toughening. The hydrogen bonding interaction drives the MXene nanosheet to self-assemble into an interconnected network around the PU latex microsphere. Thanks to the synergy of dynamic physical networks and high-density interfacial hydrogen bonding, the composites with controllable room temperature self-healing efficiency (76.5–95.9%) and tensile strength (17.7–42.6 MPa). Furthermore, the MXene network structure of the composite endows the actuator with an efficient photothermal conversion efficiency, fast responsiveness, and even functional recovery. It is an effective strategy to achieve high-strength self-healing materials through hydrogen bonding connected MXene network and interfacial hydrogen bonding aggregation, which is expected to be applied to other flexible devices, such as flexible sensors and electromagnetic shielding. [ABSTRACT FROM AUTHOR]

We demonstrate a multiblock polyurethane whose properties are precisely regulated by molecular proportion. Excellent mechanical and shape-memory qualities are displayed by the polymer. Furthermore, through internal elastic amorphous molecule segments, the material can exhibit stress-free two-way shape memory capability. The polyurethane offers a brand-new strategy for stress-free 2WSMP preparation and has numerous potential uses in artificial muscles, actuators, ligaments, and other fields. [Display omitted] • Two-way shape memory polyurethane with ultra-high strain and true tensile strength. • Stress-free two-way shape memory behaviour. • Special "molecular spring" strucure acted by polymer segments. • Adjustable shape memory behavior and mechanical properties of polyurethane. Two-way shape memory polymers (2WSMP) are highly desired for artificial muscles, soft actuators and sensors, while the stress-free 2WSMP greatly expands the practical potential of shape memory polymers. However, traditional 2WSMP cannot show high strength or good mechanical properties, which limited its practical application. It is important to create a new reversible polymer system in order to obtain more intricate movements, precise control and great mechanical properties. Herein, a two-way shape memory polyurethane was created using a new molecular strategy, which shows great properties, i.e., 2342% super stretch strain, 591 MPa true tensile strength, 708.04 J/kg of energy density, and 667.96 W/kg of power density. In addition, the 2WSMP could achieve a maximum 24.53% reversible transformation under 1 MPa stress, and 13.7% two-way shape change without external stress, respectively. In this polyurethane, the great mechanical properties and stress-free two-way shape memory effect are caused by the elastic polybutadiene (PB) segments, which acts as a "molecular spring." Furthermore, this 2WSMP could simulate reversible muscle-like motion, and be employed in ligaments. Consequently, this polyurethane offers a fresh design concept for stress-free two-way performance memory polymers and has a wide range of potential applications in the field of artificial muscles, soft actuators and ligaments. [ABSTRACT FROM AUTHOR]

• Self-healing polyurethane (PU) elastomer with mechanical robustness is prepared. • Aromatic disulfide introduces hierarchical H-bonds and loosely-stacked hard domains. • Aromatic disulfide induces soft segment crystallization during stretching. • The strain-induced crystallization behavior and mechanism are revealed. Developing new strategies to improve the mechanical robustness of self-healing polymer materials to meet engineering requirements remains a great challenge and research focus. Herein, a self-reinforcing strategy of self-healing polyurethane (PU) elastomer is presented to achieve simultaneous giant tensile strength (33.3 ± 1.7 MPa) and toughness (141.9 ± 3.7 MJ m−3). Two chain extenders, diethyl 2,2-bis(hydroxymethyl)malonate (BDMH) and bis(4-hydroxyphenyl) disulfide, are elaborately regulated in the molecular structure to balance the mechanical and self-healing properties. On the one hand, BDMH containing abundant ester groups provide a large number of hydrogen bond (H-bond) acceptors. On the other hand, the incorporation of aromatic disulfide forms reversible hierarchical H-bonds confined to loosely-stacked hard domains and improves the physical crosslinking density, thus realizing the self-reinforcing of PU elastomer based on the strain-induced crystallization (SIC) of polytetramethylene ether glycol (PTMEG) as the soft segment. Hierarchical H-bonds with dynamic nature acting as sacrificial bonds can dissociate and regenerate and dissipate a large amount of energy, thus contributing to mechanical robustness and self-healing properties. In addition to constructing a self-healing PU elastomer with mechanical robustness, a remarkable progress over previous work is that we perform fundamental study at the molecular level and reveal the three-stage evolution of H-bonds and aggregation structure during stretching, thus revealing the SIC behavior and mechanism, which provides a theoretical basis for the strengthening and toughening of self-healing PU elastomer. [ABSTRACT FROM AUTHOR]

[Display omitted] • Floatable P-ZsZc was prepared by pre-seeding ZnO followed by hydrothermal treatment. • P-ZsZc shows an uplifted valence band and new covalent Zn-O-C bonds. • Combining ZnO with PU improves photo-corrosion by boosting the h+ mobility. • Scavenger experiments and ESR spin trap analysis revealed H 2 O 2 as the main ROS. • The P-ZsZc achieved up to ∼ 90% SMX removal in continuous flow experiments. A highly efficient rigid floatable photocatalyst was prepared by seeding ZnO in polyurethane (PU) and subsequent hydrothermal ZnO coating (P-ZsZc). Compared to pristine ZnO, granular P-ZsZc had an uplifted valence band (VB) and generated new covalent Zn-O-C bond between PU and ZnO, resulting in a significantly enhanced photocorrosion resistance by boosting the mobility of photoexcited holes. In addition, the VB of P-ZsZc was favorable for the in-situ oxygen evolution reaction (OER) and H 2 O 2 production. As a result, the P-ZsZc achieved ∼ 98% removal of sulfamethoxazole (SMX) within 2 h for 5 consecutive cycles. Moreover, the SMX removal rate and Zn(II) leaching remained at ∼ 0.036 min−1 and 0.17 mg L−1, respectively, even during the fifth cycle for 10 h. Furthermore, scavenger experiments and electron spin resonance (ESR) spin trap analysis revealed that the main photogenerated reactive oxygen species (ROS) was H 2 O 2. Floatable P-ZsZc showed constant SMX removal of ∼ 90% in continuous flow experiments (CFEs) for up to 10 h of operation. This study offers a new approach to prepare floatable rigid photocatalysts capable of in-situ oxygen and H 2 O 2 production to degrade organic pollutants. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The dispersion of reduced graphene oxide (RGO) in polymer matrix was improved. • In situ incorporation of titanate functionalized RGO into polymer was used. • Isopropyl tri(diotylpyrophosphate) titanate (T3) was a good modifier for RGO. • The compatibility and interaction between T3-RGO and polymer were improved. • The one-component coating displayed excellent long-term corrosion resistance. Abstract Achieving a uniform dispersion of reduced graphene oxide (RGO) nanosheets in waterborne polymer matrix remains a challenge. Here, we significantly improved the dispersion stability of RGO in a polymer matrix through functionalizing RGO with titanate coupling agent of different dendritic structure. Titanate coupling agents of two branched dioctylpyrophosphate (T2) and three branched dioctylpyrophosphate (T3) were used. Rather than simply blending graphene with polymer matrix, functionalized graphene (T2-RGO or T3-RGO) was introduced into the reaction system with monomers to participate in the polymerization; resulting in improved compatibility and interaction between the graphene and polymer, especially for T3-RGO. One-component waterborne poly (urethane-acrylate) nanocomposite coatings (WPUA/T2G or WPUA/T3G) were then obtained. The particle size of WPUA/T3G colloidal particle size is much smaller than that of WPUA/T2G, the colloidal stability was also increased with the incorporation of T3-RGO. Compared with pure WPUA, the tensile strength of WPUA/T3G nanocomposite increased from 17.78 MPa to 40.01 MPa, and the elongation at break increased from 249% to 424%. The tensile strength and elongation at break of WPUA/T2G were 32.01 MPa and 366%, which were inferior to that of WPUA/T3G. Moreover, in comparison with pure WPUA, the impedance modulus of WPUA/T3G increased from 1.12 × 105 Ω.cm2 to 1.15 × 108 Ω.cm2, the coating resistance of WPUA/T3G increased from 8.41 × 104 Ω.cm2 to 1.39 × 108 Ω.cm2, which was also much higher than the impedance modulus (6.93 × 106 Ω.cm2) and coating resistance (7.31 × 106 Ω.cm2) of WPUA/T2G. WPUA/T3G nanocomposite coating exhibited excellent long-term corrosion resistance, being superior to the previously reported performance of solventborne polyurethane/graphene composite. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • PANI-ZnO nanocomposite (2%) has a remarkable effect on the surface characteristics of PU. • Modified films exhibit superior mechanical properties and surface hydrophilicity. • A passive method of antifouling property against a broad range of marine organisms. Abstract Eco-friendly antifouling coatings are considered to be superior alternatives over conventional biocidal agents that affect marine life adversely. Considering this fact, polyurethane (PU) films modified with a novel pigment [Polyaniline-Zinc oxide (PANI-ZnO) nanocomposites, 1–2% w/w] and phytic acid as a chelating dopant have been developed. The structure has been elucidated using Infrared Spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and the surface properties of the films were explored by using atomic force microscopy, contact angle measurements, and swelling ratios. PANI-ZnO nanocomposite particles conferred excellent chemical, mechanical and thermal properties to the PU films. The antifouling properties of the modified PU films were tested against marine bacteria (Gram negative: Vibrio harveyi and Gram positive: Bacillus licheniformis) both qualitatively and quantitatively (80 to 12% for V. harveyi and 75 to 20% for B. licheniformis). In-vitro studies displayed good antifouling performance of the modified PU-PANI-ZnO films. The present study offers a simple, moreover a passive (green) technology that allows restoration of submerged surfaces with minimal detrimental effect on marine flora and fauna. [ABSTRACT FROM AUTHOR]

Rigid PU foams are properly recycled by a single-phase glycolysis process employing crude glycerol as transesterification agent. A high pure recovered polyol (71% of purity) was obtained using a mass ratio of PU scraps to crude glycerol of 1 to 1, a reaction temperature of 190 °C and stannous octoate as catalyst in a 1.3 wt% concentration. PU foam composites containing thermoregulating microcapsules constituted by a paraffin core (Rubitherm®RT27) and a polymer shell material (LDPE and EVA) were glycolyzed, allowing to recover the microcapsules components and the polyol separately. This way, both components of the composite are recovered and can be reused in the manufacturing of new products; demonstrating for first time the viability of the chemical recycling of this kind of composites. Besides, the developed process was successfully applied for foams containing different proportions between the hard and soft segments, demonstrating its robustness. Finally, the recovered polyols were successfully employed to replace a raw rigid polyether polyol in the synthesis of new rigid PU foams. The most important physical and mechanical properties (density, maximum compressive strength and Young modulus) were maintained constant for the incorporation up to a 25 wt% of recovered polyol coming from conventional rigid PU foam scraps and up to a 37.5 wt% with the recovered polyol from rigid PU foam containing thermoregulating microcapsules. Regarding the effective thermal conductivity, it remained constant, even with 100 wt% of recovered polyol from PU scraps with thermoregulating microcapsules. [ABSTRACT FROM AUTHOR]

Mimicking the mechanical properties of native tissues is a critical criterion for an ideal tissue engineering scaffold. However, most biodegradable synthetic materials, including polyester-based polyurethanes (PUs), consist of rigid polyester chains and have high crystallinity. They typically lack the elasticity of most human tissues. In this study, a new type of biodegradable PU with excellent elasticity was synthesized based on the controlled crosslinking of poly(ester ether) triblock copolymer diols and polycaprolactone (PCL) triols using urethane linkages. Three-dimensional (3D) porous scaffolds with a defined geometry, tunable microstructures, and adjustable mechanical properties were synthesized in situ using an isocyanate-ended copolymer, a tri-armed PCL, and a chain extender. The mechanical properties of the scaffolds can be easily tuned by changing the ratio of reactants, varying the solution concentration, or using a porogen. Notably, all of these scaffolds, although mostly made of rigid PCL chains, showed remarkable elasticity and cyclical properties. With an optimized molecular design, a maximum recovery rate of 99.8% was achieved. This was because the copolymer provided molecular flexibility while the long chain crosslinking of PCL triol hindered crystallization, thus making the PU behave like an amorphous elastic material. Moreover, the in vitro cell culture of 3T3 fibroblasts and MG63 osteoblast-like cells confirmed the biocompatibility of these PU scaffolds and revealed that scaffolds with different stiffnesses can stimulate the proliferation of different types of cells. All of these attributes make PU scaffolds extremely suitable for the regeneration of tissues that experience dynamic loading. [ABSTRACT FROM AUTHOR]

Production of polyurethane is increasing since the recent years. Nevertheless, this production uses hazardous chemicals, which is isocyanate. Academy has put a lot of effort to develop some non-isocyanate polyurethane routes. One of the most promising is the aminolysis of cyclic-carbonate by diamine. To industrialize this way of production, kinetic and thermodynamic data are needed. The first steps were to optimize the production of methyl oleate, epoxidized methyl oleate and carbonated methyl oleate. Then, a kinetic model was built for a model reaction which is the aminolysis of carbonated methyl oleate by n-butylamine by taking into account the side reaction of amidation. The model fits correctly the experimental data. A Tian-Calvet calorimeter was used to determine the different reaction enthalpies. It was found that the reactions of aminolysis and amidation were low exothermic reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Repeatable self-healing polyurethane-FrGO composite coatings were prepared inspired by the self-healing principle of animal cartilage tissue. • Mechanical properties of composite coating were significantly enhanced with the introduction of 1 wt% of FrGO. • MPU-FrGO3 had outstanding anticorrosion function. • MPU-FrGO3 had excellent antibacterial and anti-algae functions. • MPU-FrGO3 showed distinguished self-healing under NIR light. Micro-cracking caused by the impact of gravel in the ocean is an important factor affecting the longevity of the integrated antifouling and anticorrosion coating. Inspired by the animal cartilage tissue, a series of polyurethane composite coatings (MPU-FrGO) with repeatable self-healing functions were successfully prepared. MPU-FrGO are endowed with excellent antifouling and anticorrosion ability because they contain functional reduced graphene oxide (FrGO) and 2-methyl 4-isothiazoline 3-ketone (MIT). As animal cartilage tissues, two-dimensional structure of FrGO forms hydrogen bond crosslinking and chemical crosslinking with polyurethane in MPU-FrGO. The super strong spatial network endows MPU-FrGO3 (the amount of FrGO added is 1 wt%) with excellent mechanical properties and strong self-healing ability. Its stress (35.6 MPa) and strain (861%) is far more than that of PU-FrGO0 (27.2 MPa and 762%). MPU-FrGO3 showed exceptional self-healing performance, and the self-healing efficiency could reach 91% (91% of initial stress) after 15 min of NIR irradiation; the self-healing efficiency of five cycles can reach more than 83% (83% of initial stress). The |Z| 0.01Hz of MPU-FrGO3 can still maintain 3.34 × 108 Ω·cm2 after immersed in 3.5 wt% NaCl for 15 days because of the excellent barrier performance of FrGO. Owing to the excellent antibacterial and anti-algal functions of FrGO and MIT, the antibacterial ability and algae inhibition coverage ability of MPU-FrGO3 were 99.5% and 97.1%, respectively. The work provides a heuristic perspective for the design of polymer materials with anticorrosion, antifouling, and self-healing. [ABSTRACT FROM AUTHOR]

Copper-containing bioactive glasses (Cu-MBGs) are attracting increasing interest as multifunctional agents for hard and soft tissue healing due to the ability of released copper ions to stimulate osteogenesis as well as angiogenesis and to impart anti-bacterial properties. The conjugation of these nanomaterials with a vehicle phase based on thermosensitive hydrogels represents an effective strategy to design non-invasive injectable devices for the in situ delivery of therapeutic ions from MBGs. In this contribution, Cu-containing MBGs were prepared by an aerosol-assisted spray-drying method (MBG_Cu 2%_SD) in the form of microspheres (surface area of ca 220 m 2  g −1 ) and through a sol-gel synthesis (MBG_Cu 2%_SG) in the form of spheroidal nanoparticles (surface area above 700 m 2  g −1 ). Both Cu-containing samples were able to release copper ions, although with different rates and percentage release. MBG_Cu 2%_SG released the total incorporated amount of Cu ions with a faster kinetics compared to MBG_Cu 2%_SD, that released approximately the 60% of copper. Cu-MBGs were incorporated with a final concentration of 20 mg/mL into a thermosensitive sol-gel system consisting of a novel amphiphilic poly(ether urethane) based on a commercialy available Poloxamer 407 (P407), with improved gelation ability, mechanical strength and stability in aqueous solution with respect to native P407. Cu-MBG-loaded hydrogels were characterised in terms of sol-to-gel transition temperature and time, injectability and stability in aqueous environment at 37 °C. The hybrid formulations showed fast gelation in physiological conditions (1 mL underwent complete sol-to-gel transition within 3–5 min at 37 °C) and injectability in a wide range of temperatures (5–37 °C) through different needles (inner diameter in the range 0.6–1.6 mm). When embedded into the hydrogel, Cu-MBGs retained their release properties, showing a sustained delivery of Cu 2+ along 14 days. [ABSTRACT FROM AUTHOR]

[Display omitted] • The DW-PU composite was prepared by vacuum immersion of delignified wood with PU. • The DW-PU 1.00 -GPEs exhibited outstanding ion conductivity of 2.90 × 10−2 S cm−1. • DW offered ion transport channels which enhanced the performance of assembled SCs. • The SCs showed excellent cycling stability and energy density of 11.49 W h kg−1. In recent years, more and more people have realized the importance of green and sustainable development. Wood as the most abundant natural biodegradable material on the earth, the preparation of high strength transparent wood (TW) by filling the delignified wood (DW) with resin is a hot research topic at present. Taking this as inspiration, here gel polymer electrolytes (GPEs) with high ionic conductivity were prepared by using DW as substrate, polyurethane (PU) with different ratios of polyethylene glycol (PEG) to 2,2-bis(hydroxymethyl)propionic acid (DMPA) as filling polymer matrix and lithium perchlorate (LiClO 4) as electrolyte through vacuum perfusion method, and applied in solid-state supercapacitors (SCs) with activated carbon as working electrodes. The cell cavity retained in DW provided a controllable ion transport channel, which further improved the efficiency of ion transport and storage. The synthesized DW-PU 1.00 -GPE possessed a splendid ionic conductivity of 2.90 × 10−2 S cm−1 at room temperature (RT). The solid-state SCs assembled with the DW-PU 1.00 -GPE also displayed the highest specific capacitance of 157.7 F g−1 at 0.3 A g−1, the outstanding E cell of 11.49 W h kg−1 and a long cycling life of 4000 cycles with 95 % capacitance retention and nearly 100 % coulomb efficiency. The DW-PU-GPEs achieve efficient Li+ transport with the help of rich internal cavities, especially showing excellent ion conductivity which possess a great development prospect in the application of SCs and broaden the application of wood in the field of electrochemistry. [ABSTRACT FROM AUTHOR]

The production of strong and elastic polyurethane nanocomposites toughened with nanocellulose (NC) and their widespread application in many engineering fields are currently limited by poor processability via classical industrial processing methods and/or the usage of large amount of solvents. In this report, we demonstrate a scalable, organic solvent-free incorporation of nanocellulose into thermoplastic polyurethane (TPU) and a remarkable reinforcement without compromising elastic properties. The nanocomposites were prepared via water-assisted dispersion of nanocellulose in polyether polyol by bead milling, drying and reactive extrusion of this dispersion with comonomers. Upon the incorporation of nanocellulose (0.5 wt.%), as observed from infrared spectroscopic and thermal analysis, the phase mixing of hard and soft-segments in the TPU matrix and the primary relaxation temperature have slightly increased due to the hydrogen bonding, interfacial area and nucleation-enhanced by long polar nanocrystals. The TPU/nanocellulose nanocomposites prepared with an appropriate stoichiometric ratio (determined through appropriate process control) showed a remarkable improvement (up to 43%) in ultimate tensile strength without compromising the elastic properties including elongation, creep and hysteresis. [ABSTRACT FROM AUTHOR]

A bioinspired self-stratification strategy to simultaneously achieve the antifouling, self-healing, and strong substrate adhesion for a coating has been developed. [Display omitted] • Bioinspired self-stratification strategy. • Excellent antifouling abilities against proteins, bacteria and diatoms. • Good self-healing performance at room temperature in air and water. • Strong substrate adhesion even in wet and underwater environments. Antifouling ability and substrate adhesion are typical trade-offs seen for a silicone coating. Furthermore, the self-healable inability limits their duration. This study reports a bioinspired self-stratifying coating composed of a polyurethane with dopamine and silane pedant groups and a bi-silanol-terminated poly(dimethylsiloxane) with fluorocarbon and poly(ethylene glycol) segments as a reactive amphiphilic polymer (RAP). During coating formation, the RAP with low surface energy can be enriched on the surface due to the self-stratifying effects, whereas the bioinspired dopamine and silane groups provide the coating with strong substrate adhesion. Besides, the multiple hydrogen bonds formed between the urethane linkages and the dopamine groups allow the coating to heal. Our study indicates such a polyurethane-based coating has excellent antifouling ability against proteins, bacteria, and diatoms, good self-healing performance at room temperature in air and water, as well as high adhesion strength on various substrates such as ceramic, steel, glass, and wood. This study provides a promising and universal strategy for the simultaneous realization of antifouling, self-healing, and strong substrate adhesion. The coatings could meet the needs of applications in marine antifouling, biomedical instruments, and other fields. [ABSTRACT FROM AUTHOR]

Conductive self-healing hydrogels (CDAH) with biodegradability and biocompatibility are synthesized from dialdehyde polyurethane (DAPU-NPs) nanocrosslinker (∼36 nm), gold-nanoparticles (Au-NPs, ∼15 nm), and O-carboxymethyl chitosan (CMC). They are featured with injectability, anti-inflammatory activity, and reactive oxygen species (ROS) scavenging capability. Animal studies support these electroactive hydrogels as neuroprotective biomaterials to improve the motor function for Parkinson's disease (PD). [Display omitted] • The conductive self-healing hydrogel is created with a dynamic network structure. • The self-healing hydrogel has proper conductivity (2–4 mS/cm). • The hydrogel is injectable by a small-gauge (30G) syringe needle. • The hydrogel exhibits biodegradability and anti-inflammatory effect. • Brain injection of the hydrogel rescues motor function in Parkinson's disease rats. Parkinson's disease (PD) is one of the most common neurodegenerative diseases with the characteristics of a progressive loss of dopaminergic neurons. Biomaterials employed in the treatment of PD are challenging and still limited. Herein, we designed and synthesized conductive hydrogels with the self-healing and anti-inflammatory properties from dialdehyde polyurethane (∼36 nm) nanocrosslinker, gold nanoparticles (∼15 nm), and O-carboxymethyl chitosan under physiological conditions. These hydrogels showed stable crosslinking network, proper conductivity (2–4 mS/cm), small-gauge needle (30G) injectability, and good biodegradability. Furthermore, the hydrogel promoted the proliferation and differentiation of neural stem cells (NSCs) towards neuronal cells. The anti-inflammatory effect and rescue function on inflammatory NSCs (∼80%) were also demonstrated in vitro. Animal experiments confirmed that injection of the conductive hydrogel in the brain recovered the motor function of the PD rats, signified by the relief of the spontaneous circling speed and impaired forelimb usage. Histological analyses showed that injection of the conductive hydrogel increased the density of tyrosine hydroxylase positive neurons and fibers, as well as reduced the inflammatory responses. The in vitro and in vivo findings indicate that this conductive, self-healing, and biodegradable hydrogel with anti-inflammatory nanocomponents may serve as a promising vehicle without additional cells or drugs for the treatment of PD. [ABSTRACT FROM AUTHOR]

This study informs harmful chemicals generation from polyurethane waste into the environment and suggests sustainable disposal platform with waste valorization. [Display omitted] • Automotive seat form (ASF) was upgraded into value-added products through pyrolysis. • Ni catalyst converted harmful aromatic chemicals into syngas. • CO 2 synergistically contributed to harmful chemical conversion into syngas. • CO 2 also contributed to extended catalyst stability in catalytic pyrolysis of ASF. In automotive industry, plastic consumption has substantially increased due to its affordability, durability, and lightness. However, the massive generation of plastic wastes from the automotive industry becomes a growing environmental concern. Current disposal methods of end-of-life vehicles (ELVs) are incineration and landfilling, but these methods generate toxic chemicals and leachate into the environment. To propose more sustainable disposal platform for ELVs, this study used a pyrolysis process using CO 2 as a reaction medium. As a case study, automotive seat form (ASF) in ELVs was disposed and valorized through the CO 2 -assisted pyrolysis. ASF, composed of polyurethane, generated harmful aromatic compounds during pyrolysis process such as benzene, aniline and their derivatives. To convert harmful chemicals into value-added syngas (H 2 and CO), catalytic pyrolysis of ASF was performed using a nickel catalyst. Effects of both CO 2 and nickel catalyst showed 89.9 wt% reduction of toxic chemical production by converting them into syngas, as comparing to pyrolysis without Ni catalyst. Gas-phase-reaction between CO 2 and pyrogenic products from ASF resulted in more than 200 times of CO production. Also, CO 2 suppressed catalyst deactivation. Therefore, this study suggested that CO 2 and plastic waste from ELVs can be converted to value-added products through CO 2 -assisted catalytic pyrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • A tape-strategy to get superhydrophobic surface on various substrates was advanced. • The tape contains polyurethane (PU) and multiwall carbon nanotubes (MWCNTs) parts. • The tape has superhydrophobicity, self-healing, self-adhesion, and conductivity. • Multifunction relies on MWCNTs planting, PU's crosslinking density, and S-S bond. • Random multifunctional patterns can be gained by pasting and self-healing process. Recently, integrating multifunctionality into superhydrophobic surfaces is becoming a tendency to meet the complexity of substrates and practical applications. However, the types of multifunctional superhydrophobic surfaces are limited and effectively constructing superhydrophobic surfaces on random substrates especially with special materials, environments, or shape is still a challenge. Herein, a tape-strategy to obtain superhydrophobic surfaces with special properties just by a simple pasting process is reported. In detail, multifunctional superhydrophobic tape is achieved through the method of spraying the superhydrophobic conductive carbon nanotubes on polyurethane (PU) coating, which could conveniently manufacture the superhydrophobic surfaces on various solid substrates (Al, CF/EP, polyimide, and glass). Depending on the proper crosslinking density of PU, existing of disulfide-bond, and uniform distribution carbon nanotubes, the obtained tape endows the solid surfaces with the multifunctional performance of superhydrophobicity, desirable self-adhesive/self-healing properties as well as conductivity. Moreover, the tap could fabricate arbitrary patterns by a simple pasting and heating process, which is adaptable for various shapes or substrates. Generally, this work provides new sights for fabricating multifunctional superhydrophobic surfaces, and the tap would have promising potential in electromagnetic stealth cloth, various multifunctional sensors, the motion monitoring, or other applications in future. [ABSTRACT FROM AUTHOR]

Polyurethane (PU), a honeycomb structure material, was used as a substrate onto which TiO 2 and Cu–TiO 2 were deposited in order to integrate the adsorption property to the photocatalysts. TiO 2 deposited on PU (TiO 2 /PU) and Cu-doped TiO 2 deposited on PU (Cu–TiO 2 /PU) were synthesized and applied to the removal of Candida famata ( C. famata ), a frequently encountered airborne yeast. The removal capacities of C. famata by PU, TiO 2 /PU and Cu–TiO 2 /PU were 1.5 × 10 5 , 3.2 × 10 5 and 6.9 × 10 5 (CFU/cm 3 ) under dark condition and 1.5 × 10 5 , 3.3 × 10 5 and 1.8 × 10 6 (CFU/cm 3 ) under visible light irradiation, respectively. PU and TiO 2 /PU seemed to exhibit only an adsorption ability for removing C. famata in aerosols under both dark and visible light. The C. famata removal capacity of Cu–TiO 2 /PU under visible light was increased 2.6-fold compared to that under dark condition. This significant increase was attributed to the Cu dopant, which enhanced the electron–hole separation efficiency and capacity of TiO 2 , resulting in the high photocatalytic activity of Cu–TiO 2 /PU under visible light. [ABSTRACT FROM AUTHOR]

We investigated a novel approach by synthesizing an integrated material, which could act as both adsorbent and photocatalytic material, for bioaerosol purification under visible light conditions. Ag was used as a dopant agent to enhance photocatalytic activity of TiO 2 , leading to high photocatalytic activity of the doped TiO 2 even under visible light. Under visible light, the doped TiO 2 photocatalyst could produce oxy radicals, oxidative agents, that participate in oxidation reactions to decompose important organic components of bacteria, leading to death or removal of bacteria from an aerosol. Adsorption property was integrated into the enhanced TiO 2 photocatalyst by using polyurethane (PU), a honeycomb structure material, as a substrate for coating process of the doped TiO 2 . Three materials including pristine PU, TiO 2 coating on PU (TiO 2 /PU), and Ag-doped TiO 2 coating on PU (Ag–TiO 2 /PU) were used to remove Escherichia coli in an aerosol under visible light. Under dark conditions, the removal capacities of E. coli in the aerosol by PU, TiO 2 /PU, and Ag–TiO 2 /PU were 1.2 × 10 5 , 2.7 × 10 5 , and 6.2 × 10 5 (CFU/cm 3 ), respectively. Under visible light irradiation, the removal capacities of E. coli in an aerosol by PU, TiO 2 /PU, and Ag–TiO 2 /PU were 1.2 × 10 5 , 2.7 × 10 5 , and 1.8 × 10 6 (CFU/cm 3 ), respectively. The improvement of the removal capacity by TiO 2 /PU and Ag–TiO 2 /PU, versus PU, is due to adsorption alone and the combination of adsorption plus photocatalytic activity, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel aromatic Schiff base-based polymeric phase change materials. • Safe, leak-free, and efficient thermal energy management. • Self-crosslinking of aromatic Schiff base for molecular firefighting. • Open a window for designing multifunctional leak-free phase change materials. Polymeric phase change materials (PCMs) have garnered enduring interest owing to no leakage and considerable latent heat in thermal management. However, the flammability, poor recyclability, and low energy storage density of typical polymeric PCMs have long-term constraint on their applications in sustainable energy. Herein, we fabricated a novel linear polymeric solid–solid PCM (HPPEG-PU) with facile recyclability, fire safety, and simultaneous high heat transition capacity via introducing aromatic Schiff base structure into the hard segment of HPPEG-PU and meanwhile using high-molecular-weight polyethylene glycol as energy-storage soft segment. HPPEG 8000 -PU achieved the latent heat of 131.1 J g−1, higher than the reported polymeric solid–solid PCMs, and realized thermal reprocessing at 80 ℃ and fire extinguishment once being ignited. Mechanisms for safe, leak-free, and highly efficient thermal energy storage/release were discussed deeply, in which aromatic Schiff base structure induced network confinement, crystallization, and self-crosslinking charring are highly responsible for shape stability, high thermal storage capacity, and fire safety, respectively. Based on the phase change characteristic of HPPEG-PU, thermosensitive imaging and convenient thermal management applications were developed in this work. Cunningly targeting aromatic Schiff base structure to polymeric PCMs may provide a promising route for safe, leak-free, and efficient thermal energy management. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly stiff and tough thermoplastic polyurethane (TPU) is fabricated. • The TPU can be printed into high performance finger orthosis. • A wireless pulse oximeter adhered to the finger orthosis by TPU can monitor the local vital signal. Mallet finger is a common athletic injury, and the current treatment involves fixing the injured finger by a splint or orthosis. 3D printing technology offers an innovative way to customize patient-specific finger orthosis that fits the individual anthropometrics. However, the existing printed materials cannot combine the high stiffness and toughness to construct an ideal finger orthosis. Herein, we report a new chain extender carrying one amide and one urea group in the side chain, and utilize it to extend polyurethane prepolymer to fabricate a highly stiff and tough thermoplastic polyurethane (TPU). Strong and mobile H-bonds in the side chain promote the formation of multiphase-separated structure in the TPU network, thus endowing this TPU with high Young's modulus (213.0 ± 3.7 MPa) and high toughness (47.8 ± 1.9 MJ m−3). Due to the dynamic H-bonds in the polymer network, this TPU exhibits an excellent 3D printing ability, and can be used to print finger orthosis by fused deposition modeling technology at an elevated temperature. The printed finger orthosis can be attached with a wireless pulse oximeter by virtue of TPU adhesiveness, thus monitoring vital physiological signals on the injured index finger that can be well fixed by the stiff orthosis. [ABSTRACT FROM AUTHOR]

Cracking or delaminating with insufficient mechanical strength of biocompatible polymer layer applied for stent coating is a major limiting factor in stent coating technology. Novel strategies and smart materials are therefore required to develop stable polymeric layer on the surface of stent. In this study, an in situ polymerization technique is applied to fabricate graphene oxide (GO) loaded electrospun PU fibers. Viscous solution of in situ polymerized GO/PU composite in mixed solvent system of DMF/MEK (1:1 by wt) was applied to fabricate GO/PU composite fibers and its application on nonvascular stent coating was performed. Microscopic analysis shows that GO sheets are evenly distributed throughout the composite nanofibers. Spectroscopic analysis indicated the formation of chemically bonded GO-PU composite fibers. Mechanical performance evaluation and water contact angle measurement of pristine and composite PU electrospun membranes (obtained from the same method) showed that a 1 wt% GO containing PU fibrous mat is far better in mechanical properties and hydrophilicity compared to the pristine PU mat. The improved properties of composite PU fibers on the surface of nonvascular stent were evaluated using durability test. Results showed that as-synthesized composite PU fibrous membrane coated on the surface of stent has no crack or delaminate upon repeated cyclic stress during standard stent durability test. Therefore, the proposed coating material and processing technology will be a promising approach for the development of hybrid stent. [ABSTRACT FROM AUTHOR]

A masterbatch of graphene oxide (GO) in polyol was prepared and used for the preparation of polyurethane (PU)/GO nanocomposites by bulk in-situ polymerization. The prepared nanocomposites were characterized in terms of their thermal, mechanical, and morphological properties as a function of GO loading. Here, grafted PU chains on the surface of GO facilitated the beneficial stress transfer from the PU matrix to GO. This stress transfer occurs due to the reaction of the hydroxyl and carboxyl groups of GO with the isocyanate groups of 4,4'-methylene diphenyl diisocyanate (MDI) and the PU pre-polymer. The Young's modulus of the PU was improved by 280.5% through the incorporation of 3 wt% GO. Additionally, an improvement of 40.5% in the tensile strength and 19% in the elasticity was achieved at 1 wt% GO. Strain hardening of PU was improved with GO loadings up to 1 wt% due to the synergetic orientation of the soft segment and the PU-grafted GO in the strain direction. However, the large increase in cross-link density that occurred at 2 wt% GO prevented strain hardening, and the ultimate tensile strength decreased. The Halpin-Tsai model was used to predict the orientation of GO in PU nanocomposites. The randomly oriented 3D arrangement of GO in PU showed better agreement between the theoretically calculated and experimentally determined moduli compared to the 2D alignment. These results demonstrate that the preparation of PU nanocomposites using masterbatch dilution is an excellent method to attain well-dispersed GO. This technique can also be used to overcome the environmental problems associated with volatile organic compound (VOC) emission, as well as addressing some of the difficulties found in the plastics processing industry. [ABSTRACT FROM AUTHOR]

• A novel polyurethane meniscus scaffold is prepared using DLP 3D printing. • Kartogenin is loaded on the scaffold and the surface is modified with polydopamine. • The mechanical properties of the scaffolds are comparable to natural meniscus. • The optimized scaffolds exhibit superior performance for meniscus regeneration. Owing to the limited healing ability, the repair of meniscal injury and prevention of secondary osteoarthritis pose considerable challenges for clinicians and researchers. While tissue engineering technology is a promising method, many difficulties, including the construction of the meniscus scaffold with appropriate mechanical properties and its functionalization to promote the regeneration of meniscus tissue, remain to be addressed. In this study, a novel structurally and functionally optimized tissue engineering meniscus scaffold with mechanical properties and spatial structure similar to those of a natural meniscus is prepared using digital light processing 3D printing technology. Kartogenin-loaded polyurethane scaffolds with a specific structure designed using finite element analysis are printed, and their surface is modified using polydopamine. The optimized scaffolds exhibit superior performance in promoting meniscus regeneration, protecting articular cartilage, and mitigating the development of osteoarthritis. Moreover, this study addresses challenges posed by polyurethane, which is found in most widely used commercial meniscus grafts, including unsatisfactory biocompatibility with stem cells and unavailability of a fine 3D structure. Although further research in preclinical applications is required, the results of this study in terms of a next-generation clinical meniscus biomaterial repair strategy are promising. [ABSTRACT FROM AUTHOR]

[Display omitted] • Advances in polyurethane-based electrolytes are comprehensively reviewed. • Synthesis routes and structure engineering methods of polyurethane-based electrolytes are elucidated clearly. • Guidance and perspective of polyurethane-based electrolytes towards industry applications are provided. Polymer electrolytes (PEs) have been widely regarded as an effective approach to eliminate most of the potential safety hazards encountered in traditional liquid electrolytes for lithium batteries (LBs). Substantial research efforts have been devoted to exploiting excellent performance PE systems, including poly(ethylene oxide) (PEO), polyurethane (PU), polysiloxane (PS), polyvinylidene fluoride (PVDF) and polycarbonate (PC)-based PEs. Among them, PU-based PEs have attracted increasing interests due to their flexibility of structure manipulation, excellent mechanical strength, facile modification, high thermal and electrochemical stability. However, to date, separated and detailed reviews on the progress of PU-based PEs are rarely reported. In this review, we comprehensively summarize the key progress on PU-based PEs from the perspective of flexible structure design strategies, basic electrochemical/mechanical properties, typical modification methods, specific functions, and their potential applications in LBs. Furthermore, synthesis routes of PUs and perspectives of PU-based PEs are also discussed. It is believed that this review will be of great guiding significance for exploiting high performance PU-based PEs for next-generation LBs. [ABSTRACT FROM AUTHOR]

• Supramolecular SSPCM based π-π stacking was prepared by facile block copolymerization of PEG, MDI and BP. • SSPCM shows super toughness and solid state even at 130 °C. • The light responsiveness and thermal conductivity of SSPCM have been improved by simple addition of CNT. The solid–solid phase change materials (SSPCMs) have become the preferred materials in thermal energy storage via absorbing latent heat from ambient environment. However, the trade-off between the mechanical properties, stability and recyclability is still the obstacle and barrier for development of SSPCMs. Herein, we proposed a facile and novel strategy to prepare SSPCMs for address above issues by introducing π-π stacking to form physical crosslinking points in linear polyethylene glycol (PEG). The strong intermolecular forces formed by π-π stacking not only prevented leakage of the PEG even at 130 °C but imparted high temperature stability and excellent toughness (172.44 MJ/m3) to fabricated SSPCMs. It is worth mentioning that the prepared PCMs can be added with CNT in a simple process way to improve the photo-thermal conversion ability and thermal conductivity of SSPCMs. Besides, the as-prepared SSPCMs exhibited excellent flexibility, and were expected to be excellent thermal/photo energy storage materials for human thermal management and wearable devices. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cost effective fly ash/PU electrospun nanofibers are fabricated for first time. [•] Fly ash is effectively loaded to increase the mechanical strength of the mat. [•] The mat has good VOCs absorption capacity and can apply for air filtration. [•] The absorption capacity of as-fabricated mat to five hydrocarbons is studied. [ABSTRACT FROM AUTHOR]

A self-healing composite coating based on the dual-action of corrosion inhibitor M−16 embedded in micro-arc oxidation coating and self-healing polyurethanes is designed for corrosion protection of Mg alloy. [Display omitted] • 1. A dual self-healing composite coating was prepared for Mg alloys. • 2. The MAO coating was more suitable to carry the inhibitor than polymer coating. • 3. The scratches of the composite coating were repaired by modified polyurethane. • 4. MAO coating enhanced the self-healing performance of the polymer coating. In this work, a new self-healing composite coating for corrosion protection of magnesium (Mg) alloy, which is based on the dual actions of the corrosion inhibitor M-16 embedded in the micro-arc oxidation (MAO) coating and self-healing polyurethane (PU) modified by disulfide bonds, is developed. Electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) are used to study the anti-corrosion performance of the scratched and healed composite coatings immersed in 3.5 wt% NaCl solution. Results show that the porous MAO coating is suitable to carry inhibitor M-16 and the anti-corrosion performance of the scratched coating is significantly improved by the inhibitor embedded in the MAO coating. The scratched coating exhibits an excellent recovery of the anti-corrosion performance after the heat treatment, which is attributed to the cooperation of dynamic disulfide bonds and shape-memory effect of the self-healing PU coating. Furthermore, it is found that the inhibitor M-16 embedded MAO coating can enhance the repair ability and anti-corrosion performance of the PU coating when the corrosion product was pre-formed inside the scratch of the composite coating. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel path to prepare the thermal-driven dual-crosslinking protein network (DCPN). • Functionalized polyurethane serves as thermal-triggered elastic dual-crosslinker. • Polyurethane-induced microphase-separated system provide plasticity for DCPN effect. • The trade-off between adhesive strength and adhesion toughness has been solved. • It offers new insights into designing practical robust protein composites. Wood products have gained considerable interest for use in furniture and construction materials; however, adhesives for bonding wood components are mainly formaldehyde-based resins, which release hazardous substances and can cause serious health concerns during service. The development of plant protein adhesives is in high demand to satisfy requirements for green wood-based composites and stringent environmental regulations. However, their practical application is hindered by the trade-off between high mechanical strength and good adhesion toughness. Herein, a biomimetic branched polyurethane is synthesised initially using a blocking agent of dopamine and sodium bisulfite to form a thermally driven dual-functionalised elastomer (PUSD). The prepared PUSD is employed as a novel dual-crosslinker for the improvement of soy protein (SP) adhesives. Because of the deblocking effect of sodium bisulfite under the thermal stimulus during hot pressing, the isocyanate groups are exposed and further cooperates with catechol groups to induce the construction of a thermally responsive dual-crosslinking network within the SP system. These structures not only promote the optimisation of the crosslinking density for a rigid system but also improve the intermolecular interaction patterns, thereby achieving effective energy dissipation. Consequently, the modified SP adhesives exhibit an integrated improvement in adhesive strength, adhesion toughness, and water resistance compared to the untreated adhesive. The outcome of this work enables the utilisation of plant proteins instead of traditional wood adhesives, thus addressing health and environmental concerns. [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile route to prepare novel inter-diffused zwitterionic PU coatings was presented. • The inter-diffused PU coatings showed desired inhibitory efficacy against bacterial attachment. • The inter-diffused PU coatings exhibited superior mechanical durability for long-term use. • Scalability of the PU coatings was demonstrated for potential practical application. In the past decades, the omnipresent bacterial attachment and biofilm formation on surfaces have facilitated the transmission of infectious diseases on global scale, inflicting significant public health concern and financial burden. Among the most affected surfaces, polyurethane (PU) based coatings used in wide range of human-touching settings were profoundly influenced by bacterial adhesion. To eliminate the undesired bacterial attachment on PU coatings, we designed a novel zwitterionic polyurethane (ZPU) with high content of sulfobetaine zwitterionic moieties for enabling surface hydrophilicity to hydrophobic acrylic polyurethane (APU) via an inter-diffused structured coating. The diffusion between ZPU and the underlying APU base ensures long-lasting surface hydrophilicity by allowing the zwitterionic moieties to be anchored into the interior of the coating films. Moreover, the excess ZPU on the surface during inter-diffusion also enhanced biocompatibility by quenching the toxic isocyanate groups on the surface. Compared with simple blending of ZPU into APU as an additive, the novel route demonstrated improved toughness of 3.14 MPa and superior antibacterial efficacy due to the enriched ZPU on the coating surface. The antibacterial property against bacterial attachment was retained even after the coating surface was mechanically abraded for 1000 cycles. Moreover, the inter-diffused PU coating can be readily applied onto commercialized vinyl tarpaulin on large scale via similar spray coating process. A relatively low batch-to-batch deviation with no delamination was observed, suggesting the inter-diffused PU coating is feasible to be readily scaled from laboratory to practical production. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes a one-step fabrication of tourmaline (TM) nanoparticles (NPs)-decorated polyurethane (PU) composite nanofibers with superhydrophilic and antibacterial properties. The physico-chemical properties of the prepared samples were characterized by different characterization techniques. FESEM and TEM images confirmed the presence of well-dispersed TM NPs in/on PU nanofibers. The incorporation and homogeneous dispersion of 3wt% TM NPs in PU exhibited an increase in tensile strength and modulus of 75% and 87%, respectively from those of the neat PU. All TM/PU composite mats showed improved hydrophilicity compared to neat PU mat, and a superhydrophilic surface with a contact angle of 13° was obtained at 5wt% TM content. FTIR spectra confirmed the interaction of TM NPs to PU matrix through hydrogen bonding. Bacterial tests showed high zone inhibition for both Escherichia coli (Gram-negative) and Enterococci (Gram-positive) using the TM/PU composite mats with increasing efficiency as with the increase of TM NP content. The present TM/PU composite mat, which has improved mechanical properties, superhydrophilic surface, and good antibacterial properties, may be a potential candidate as an antibacterial material, in the field of health-protection textile and water filtration. [Copyright &y& Elsevier]

The elegant choice of non-planar ring structure and adoption of sulphur containing chemical bonds in main chain are the key factors in obtaining anti-stress relaxation, anti-fatigue, anti-fungal and self-healing poly(thiourethane-urethane) elastomer for durably stretchable device. This polyurethane successfully pass through the long term tension, cyclic tension, mildew environment and accidental damage tests. [Display omitted] • Non-planar rings increased the anti-stress relaxation and anti-fatigue properties. • The thioether and thiourethane endow the mildew proof and self-healing properties. • Anti-stress relaxation, anti-fatigue, anti-fungal and self-healing are integrated. Considering the complicated environment in daily use of stretchable devices, the capabilities of anti-stress relaxation, anti-fatigue, anti-fungal and self-healing are very much appreciated, and the above four functionalities largely depend on the elastic matrix. Here, these demands are fulfilled by a poly(thiourethane-urethane) elastomer CBPU-3. In detail, a large amount of cyclohexane rings, with completely reversible boat–chair conformational transition, are introduced into the backbone of poly(thiourethane-urethane), and such non-planar ring imparts molecular elasticity and modulus into the elastomer, resulting in remarkable anti-stress relaxation and anti-fatigue abilities. Even after 20 h fixation at 300% strain and 1000 times cyclic tensile (50% strain), the recovery ratio could still be higher than 98%, and its stable microstructure is proved by SAXS scattering patterns. In addition, the thioether bond ensures the effective mildew proof ability, and the mechanical properties and transmittance change little even after a severe mildew pollution for 30 days. Simultaneously, the relatively lower bond energy of C-S (62.0 Kcal/mol) in thiourethane bonds endowes the poly(thiourethane-urethane) with self-healing capability (highest: 40 μm/min at 80 °C). Finally, the durability and usability of the deformable resistive sensor array based on this elastomer as the matrix are drastically enhanced due to the above integrated functionalities. [ABSTRACT FROM AUTHOR]

• A review on flame-retarded thermoplastic polyurethane elastomer. • From organic materials to nanocomposites and new prospects. • Inherent and additive-type flame-retarded thermoplastic polyurethane elastomer. • Organic, inorganic, compound, and hybridized flame retardants. Thermoplastics polyurethane elastomers (TPUs) have been widely used in auto parts, electronic appliances, wires and cables, et al. However, they are flammable, thus seriously threating the safety of human beings and property. To achieve the flame retardancy of TPUs and reduce the hazards from smoke and toxic gases as well as severe droplet, much work was carried out in the past two decades, especially in the recent decade. In this review, we focus on the fire safety of TPU and deeply review the past and current status concerning the flame retardation of TPU, covering organic materials to nanocomposites and new prospects. Starting from the structural characteristic, several basic aspects of TPU are overviewed, including thermal properties, combustion performance, and flame-retardant method. Then, on the basis of published literatures, the development course, current research hot spot, and difficulty in achieving the flame retardancy of TPU are analyzed by detailed statistic data. Further, existing inherently flame-retarded TPU and already used flame retardants in TPU are introduced thoroughly. For the most important additive-type flame-retardant mode currently, the structural design and flame-retarding effect of vital flame retardants on the fire safety of TPU are discussed in detail, which includes mono-component organic and inorganic flame retardants, modified and hybridized flame retardants, compound flame retardants, and nano flame retardants. For inherently flame-retarded TPU, this review focuses on the structural design and flame-retardant mechanism. In addition, special processes to the flame retardation of TPU are also discussed. On the basis of the past research, the flame retardation of TPU without the incorporation of traditional flame retardant elements and the bio-based flame retardation of TPU are prospected in the final part. [ABSTRACT FROM AUTHOR]

The hybrid polydiols composed of high and low crystalline polyesters were used as the degradable soft segments for desirable polyurethane. Moreover, the dynamic disulfide bond was introduced to simultaneously endow the polyurethane with self-healing and anti-aging properties. Consequently, the polyurethane integrated room temperature self-healing, anti-aging and controlled degradation capacities. • The self-healing and anti-aging could be simultaneously realized by disulfide bonds. • Degradable soft segments protected by hard segments lead to controlled degradation. • Self-healing, anti-aging and controlled degradation are integrated in a polyurethane. Two of the very important demands for the elastic matrix of electronic skin (E-skin) are durability and degradability, which ensure the stable performance in daily life and green end of the E-skin. Unfortunately, these two requirements are usually incompatible. Here, we proposed the idea of controlled degradation and synthesized a polyurethane, AL-PU-4, to solve such challenge. High crystalline hydroxy-terminated poly (1,4-butylene adipate) (HTPBA) and low crystalline polycaprolactone diol (PCL diol) were mixed and used as the degradable soft segment. The dynamic disulfide bond was chosen as the chain extender, which could simultaneously endow the polyurethane with anti-aging and self-healing properties. The AL-PU-4 didn't show significant loss in mechanical and molecular weight after 12 days of accelerated aging experiment, which equaled to 12 months of daily use, and it owned a fast room temperature self-healing speed of 1.31 μm/min. With the steric protection of the hard segment, the degradation of ester bonds in HTPBA and PCL diol segments was seriously retarded under enzymatic and low pH conditions. Only when the pH reached 14, the 'lock' on degradation was opened. The above functionalities were also verified in an E-skin demo, which could response the external pressure quickly and show high stability in cyclic test. [ABSTRACT FROM AUTHOR]

• Polyurethane sponge functionalized with Fe 3 O 4 @OA@GO nanosheets by dip coating. • The modified polyurethane (M−PU) showed a superhydrophobicity property. • M−PU sponge exhibited high performance to adsorption organic solvents and oils. • The modified PU reused for 15 time without adsorption capacity decreased. • M−PU sponge used to separation oil from water at static and dynamic states. With development of industrial activities, a lot of oil pollution is released to water environment. As such, superhydrophobic oil adsorption materials with reusability are required. For this purpose, a magnetic superhydrophobic polyurethane sponge by connecting graphene oxide was coated with functionalized oleic acid Fe 3 O 4 nanoparticles on the three-dimensional microstructure of commercial polyurethane sponge (Fe 3 O 4 @OA@GO-PU) via simple and low-cost dip coating method. Characterization analysis were used to confirm the synthesis of modified sponge. The eco-friendly effective modified sponge repelled water with contact angle 158° and selectively adsorbed organic solvents and various oils from water with high adsorption capacity. The water content obtained by distillation method was lower 1%. The adsorption capacity was improved under magnetic field exposure with various intensities due to the surface area of modified PU sponge was increased. Further the magnetic property of modified PU sponge contributed to controlling and recycling by a magnet such that it could be used for 15 times for oil spill cleanup without decline in its adsorption capacity, while exclusivity of superhydrophobic functionalized PU sponge caused selectively separation of contaminants from water. Additionally, the modified sponge could be collected oil from water continuously when being connected to a peristaltic pump. Thus, the modified sponge is an excellent adsorbent for practical applications in separation oil-polluted water. [ABSTRACT FROM AUTHOR]

The SrAl 2 O 4 :Eu2+@TPU (polyurethane) ultraviolet stimulated anti-counterfeiting film was fabricated via an electrospinning method. The film is colorless under day-light, however, it shows a predetermined green fluorescence pattern under UV light. • SAOE@TPU film has been fabricated via an electrospinning method. • The film is stretchable, flexible, transparent, and waterproof. • Film is colorless under day-light, anti-counterfeiting pattern appearing under UV. • The well-designed gaskets can be used for anti-counterfeiting cosmetics. Innovative anti-counterfeiting materials have triggered extensive interest to improve the counterfeiting of the packaging market. To exploit anti-counterfeiting mechanically reliable composites, the engineering at both material and matrix is urgent to investigate. In this work, SrAl 2 O 4 :Eu2+@TPU (polyurethane) ultraviolet stimulated anti-counterfeiting film has been successfully fabricated via an electrospinning method. Subsequently, the morphology, structure, optical transmittance, and mechanical properties of the film were systematically characterized. The anti-counterfeiting film obtained by integrating the traditional SrAl 2 O 4 :Eu2+ phosphors and the thermoplastic material TPU is stretchable, flexible, and transparent. Not only can it not be noticed by the naked eye, but also does not affect the transparency of the film. Moreover, it also possesses a unique 1D nanostructure. As a new type of anti-counterfeiting material, the film will provide both first-line and second-line anti-counterfeiting functions and excellent anti-counterfeiting strength under ambient conditions. This work demonstrated a low-cost and effective way to prepare versatile, high mechanical strength and anti-counterfeiting film, creating outstanding market potential and significant economic and social value. [ABSTRACT FROM AUTHOR]

• Graphene nanoribbon (GNR) was synthesized by oxidative unzipping of MWCNT. • PU-GNR exhibited higher mechanical properties than PU-MWCNT and PU-GnP. • 0.5 wt% GNR endowed superior long-term anti-corrosion performance to PU coating. • Mechanism of durable anti-corrosion performance of PU-GNR coatings were explained. In this study, graphene nanoribbon (GNR) was produced through oxidative unzipping of multiwalled carbon nanotube (MWCNT) to integrate high aspect ratio features of MWCNT with a planar structure of the graphene. Afterward, its structural effect (shape and aspect ratio) on mechanical and anti-corrosion performance of polyurethane (PU) nanocomposites was thoroughly investigated utilizing uniaxial tensile measurement and electrochemical impedance spectroscopy (EIS). The results were compared to MWCNT with tubular high aspect ratio and graphene nanoplatelet (GnP) with a planar low aspect ratio structure. PU-filler nanocomposites were produced with different nanoparticle loadings and applied to a cold rolled steel substrate for mechanical and anti-corrosion measurements. As a nanocomposite filler, MWCNT performs well in terms of mechanical properties, and GnP shows higher anti-corrosion performance. However, PU-GNR pronounces in both mechanical properties and corrosion resistance. Young's modulus of 0.5 wt% PU-GNR nanocomposite reaches 3.52 MPa, which is around 1.6 and 1.4 times higher than the PU-GnP (2.19 MPa) and PU-MWCNT (2.52 MPa), respectively. Furthermore, PU-GNR exhibits the highest corrosion resistance of 8.45 × 105 Ω·cm2 compared to PU-GnP with 5.14 × 105 Ω·cm2 and PU-MWCNT with 4.09 × 105 Ω·cm2. The better performance of the PU-GNR nanocomposites is attributed to the planar structure, high aspect ratio, uniform dispersion and better polymer-filler interactions. They contribute to not only improve load-bearing properties of the nanocomposite but also build a tortuous pathway suppressing corrosive agents' diffusion to the PU matrix. [ABSTRACT FROM AUTHOR]

• Robust and stretchable multifunctional aerogels were constructed. • The aerogels exhibited a maximum surface temperature of 173 °C within 70 s at 4 V. • The aerogels display hydrophobicity with a water contact angle up to 135°. • The aerogels possess excellent breathability. Multifunctional wearable heaters are highly desirable for the growing demand in the field of personal thermal management. Herein, we present an efficient and feasible strategy to construct wearable heaters using waterproof and breathable composite aerogels made from cellulose nanofibers (CNF) aerogel, polypyrrole (PPy), fluorinated finishing agent and polyurethane (PU). The named composite aerogels exhibited a lightweight structure (0.14 g/cm3), superior mechanical robustness and outstanding Joule heating performance (up to 173 °C at 4 V about 70 s). They feature a water contact angle (WCA) up to 135° enabled by the synergistic effect of the fluorinated agents and surface roughness. The aerogels also exhibited high air permeability (186.6 ± 22 L S−1 m−2) and satisfiable water vapor transmission (WVT) rate at 5.8 ± 0.8 kg m−2 d−1. These favorable features made the composite aerogels highly promising for intelligent garments, wearable devices and personal thermal management systems. [ABSTRACT FROM AUTHOR]