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Metal materials play an important role in electromagnetic interference (EMI) shielding due to their ultra‐high electrical conductivity, but they are rigid and inflexible, as well as of high density, which limits their application in some areas. In this study, a novel and simple method to fabricate the composites of metal foil and polymer is reported. A copper foil (Cuf) with micropores on the surface is used as a shielding matrix, then interpenetrating and interlocking nanostructure as well as reactive groups are introduced on its surface, and then silicone rubber (SiR) is coated on both surfaces to form a sandwich structure, and the obtained Cuf/SiR composites possesses high EMI shielding efficiency (SE), strong interface adhesion, and low density. The average EMI shielding efficiency of the obtained Cuf/SiR composites in the range of 1.13–18 GHz is 111.5 dB, with a high interface adhesion strength of 5.2 N cm−1 and low density of 1.3 g cm−3, and it also possesses bending and splicing properties, which exhibits broad potential application in the field of EMI shielding tents and shielding rooms. This preparation method of the composites is simple and efficient, and provides a guideline for the design and fabrication of metal foil/polymer composites in molding method. [ABSTRACT FROM AUTHOR]

In this study, erucamide as a non‐toxic and tasteless lubricant was melt blended with thermoplastic polyurethane (TPU) to reduce the coefficient of friction (COF) of TPU and thus to improve the wearing comfort of intelligent wearable devices. The results show that when the content of erucamide reaches percolation, erucamide can migrate to the TPU surface, forming a layer of lubrication film, and thus significantly reduces the COF of TPU. In addition, erucamide with amide groups can form hydrogen bonds with carbamate groups from TPU chains and thus can disrupt the hydrogen bonds between two amide groups of TPU chains. With the introduction of erucamide, the chain mobility of TPU increases, the partial phase mixing of soft phase and hard phase of TPU occurs, and the interchain interaction between TPU chains decreases. Under the appropriate content of erucamide (0.5 wt%), both the elasticity and processability of TPU are also significantly improved, whereas the high tensile strength, tear strength and elongation at break of the TPU blend is still obtained, facilitating its practical application in intelligent wearable devices. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Intelligent fluorescent coatings have received widespread attention in the encryption technique field such as anti‐counterfeit, while the traditional fluorescent coatings are easy to be damaged by external force. In this study, the fluorescent and self‐healing anti‐counterfeit coatings are prepared after rational molecular design. Two polymers containing fluorescent groups, including polyurethane containing the anthracene (AN) side group and polyimide containing the naphthalenediimide (NDI) structure are synthesized to realize multiple color changes with fluorescence through simply blending. Due to the overlapping fluorescence spectra of the groups, enabling the fluorescence resonance energy transfer effect (FRET), the coating with different group ratios exhibits tunable fluorescence under the same excitation light, providing diverse patterns. Moreover, due to the reversible photo‐crosslinking and thermal de‐dimerization properties of anthracene, the recording, erasure, and rewriting of the surface pattern can be realized, and the fluorescent anti‐counterfeit coatings exhibit excellent self‐healing properties after cross‐linking due to the FRET effect, which solves the problem of poor healing and ensures the stability and integrity. The fluorescent coating with cross‐linked structure and self‐healing behavior based on the FRET effect greatly expands the functional applications of traditional polyurethane materials. [ABSTRACT FROM AUTHOR]

The interfacial interactions between ultra‐high molecular weight polyethylene (UHMWPE) fiber and polymer determine the overall performance and service life of the fiber reinforced composite materials. In this article, polyaniline (PANI) layer is uniformly deposited on the surface of the UHMWPE fiber after plasma treatment to enhance the interfacial adhesion between UHMWPE fiber and rubber. At the same time, the PANI layer can also form a conductive path at the interface to monitor the damage of the composites in real time. Compared with the untreated UHMWPE fiber, the H pull‐out force of the PANI‐deposited UHMWPE fiber with rubber is increased by 67.9%, which is due to good mechanical interlocking and chemical bond between the fiber and the matrix. Moreover, the electrical resistance change during the fiber pull‐out process has a good correlation with the pull‐out force curve, which provides a new idea for in‐situ monitoring of the damage of composites. [ABSTRACT FROM AUTHOR]

In order to improve the interfacial adhesion between aramid fiber (AF) and rubber matrix, a simple and facile method of aramid nanofiber (ANF) coating is demonstrated in this article. Tannic acid (TA) and polyethyleneimine (PEI) are polymerized in an alkaline solution to form a thin TA/PEI (TP) layer that is deposited on the surface of AF to introduce functional groups such as hydroxyl and amino groups. Then, the ANF coating is utilized to construct nanostructures on the surface of AF to improve the interfacial adhesion between the fiber and the rubber. Through hydrogen bonding and/or π‐π stacking between the TP layer and the ANF, the ANF coating is firmly attached to the surface of AF. Compared with the untreated fiber, the interfacial adhesion of AF coated with ANF after 1, 3, 5, 7, 9 deposition cycles is increased by 27.8%, 29.1%, 31.5%, 43.1%, and 30.3%, and the mechanical properties of the fibers remain almost unchanged. This method shows its advantages of simple, facile, and time‐effective, which is of great significance for industrial applications. [ABSTRACT FROM AUTHOR]

It is a significant but challenging task to simultaneously reinforce and functionalize diene rubbers. Inspired by 'sacrificial bonds', the authors engineer sacrificial hydrogen bonds formed by pendent urazole groups in crosslinked solution-polymerized styrene butadiene rubber (SSBR) via triazolinedione click chemistry. This post-crosslinking modification reveals the effects of the sacrificial bonds based on a consistent covalent network. The 'cage effect' of the pre-crosslinked network facilitates the heterogeneous distribution of urazole groups, leading to the formation of hydrogen-bonded multiplets. These multiplets further aggregate into clusters with vicinal trapped polymer segments that form microphase separation from the SSBR matrix with a low content of urazole groups. The clusters based on hydrogen bonds, serving as sacrificial bonds, promote energy dissipation, significantly improving the mechanical properties of the modified SSBR, and enable an additional wide transition temperature region above room temperature, which endows the modified SSBR with promising triple-shape memory behavior. [ABSTRACT FROM AUTHOR]

In this study, polyamide-12 (PA12)/brominated isobutylene-isoprene (BIIR) TPVs with good mechanical properties and low gas permeability were prepared by dynamic vulcanization in a twin-screw extruder. The effects of three kinds of compatibilizers on the microstructure and properties of BIIR/PA12 TPV were studied. The compatibility between BIIR and PA12 was improved when maleated hydrocarbon polymeric compatibilizer is added. The reaction between maleic anhydride and amine in polyamide leads to the in situ formation of hydrocarbon polymer grafted polyamide which subsequently can be used to lower the interfacial tension between BIIR and polyamide. The compatibilizing effect of maleic anhydride modified polypropylene (PP-g-MAH) on BIIR/PA12 blends is the best among these compatibilizers because the surface energy of PP-g-MAH is very close to that of BIIR. The dispersed rubber phase of the blend compatibilized by PP-g-MAH shows the smallest size and more uniform size distribution, and the resulting TPVs show the best mechanical properties. The effects of fillers on the properties of BIIR/PA12 TPV were also investigated. The size of the BIIR phase increases with the increase in the content of CaCO3. The modulus and tensile strength of TPVs increased with the increase in the content of CaCO3 because of the reinforcing effect of CaCO3 on TPVs. [ABSTRACT FROM AUTHOR]

ABSTRACT Dynamic vulcanization to prepare blended thermoplastic vulcanizates (TPV) is a kind of complicated blending technology, where the breakup of the rubber phase happens accompanying with the crosslinking of rubber. In this study, we aim to investigate the effect of crosslinking on the breakup of chlorobutyl rubber (CIIR) phase in thermoplastic polyamide 12 (PA 12) matrix by purposely using pre-crosslinked CIIR with different crosslink degrees and plasticizer contents. Besides, the effect of blending conditions on the breakup of crosslinked CIIR phase was studied. The results show that a low crosslink degree, a high content of plasticizer, a low blending temperature and a morderate rotor speed of 70 rpm facilitate the breakup of pre-crosslinked CIIR in PA 12 matrix. This is ascribed to the decrease in the modulus of pre-crosslinked CIIR phase because of either a low crosslink degree or a high content of plasticizer, the increase in the molten viscosity of thermoplastic matrix because of a low blending temperature and a moderate rotor speed. It is indicated that the breakup of pre-crosslinked rubber is mainly dominated by the modulus of crosslinked rubber phase as well as the molten viscosity of thermoplastic matrix and shear stress. This study will provide guidance for the preparation of CIIR/PA TPV. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40765. [ABSTRACT FROM AUTHOR]

The phase morphology and toughening behavior of impact polypropylene copolymer (IPC) with and without nucleating agent (NA), prepared at different processing melt temperatures ( Tp), were investigated. Interestingly, three different structures can be formed in the IPC samples by adding NA or tuning Tp. A well-defined core-shell structure is obtained in samples with α-NA or without NA prepared at all Tp. A developing multilayered structure is mainly formed at high Tp with added β-NA, while an incomplete phase separation structure with interpenetrating chains is the dominant structure for IPC samples prepared at low Tp with added β-NA. In this case, because of the synergistic effect between phase morphology and relatively high β-form crystal content, the chain interaction among the components and chain mobility of the amorphous portion of IPC are distinctly improved, resulting in a largely improved toughness under 0 °C. This improvement in toughness is very important for applications. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In our previous work, the formation of a nanohybrid shish kebab (NHSK) structure was successfully achieved in helical polymer systems promoted by using single-walled carbon nanotube (CNT) bundles with a unique 'groove structure', which is of great crystallographic interest. To further investigate the effect of surface groove structure of CNT bundles on the formation of NHSK structure in helical polymer systems, in the work reported here double-walled carbon nanotube (DWNT) fibers with bundle structure were used as nucleating agents and orientation templates for poly( L-lactide) (PLLA) crystallization. A fine NHSK structure with controlled lateral size and period of kebabs was successfully obtained under various experimental conditions by using DWNT bundles. This could be due to the geometric confinement effect of the surface groove structure of the DWNT bundles, which could facilitate the orientation of PLLA chains along the DWNT axis and the lateral formation of a stable nucleus. Our work suggests an efficient method for the functionalization of CNTs with biocompatible PLLA, which may have some potential applications in biomedical areas. In addition, it is demonstrated that the formation of NHSK structure can effectively improve the physical bonding between PLLA and nanotubes, thus significantly improving the mechanical properties of PLLA/CNT nanocomposite fibers. Copyright © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) is derived from oxidization of natural graphite and contains many active groups. These active groups make GO a potential compatibilizer for polymer blends or coupling agent for polymer composites. In this work, a novel core-shell structured hybrid submicroparticles of graphene oxide-encapsulated silica (GO-SiO2) were fabricated using GO sheets via an electrostatic assembly between ultrathin negatively charged graphene oxide sheets and positively charged amino-modified silica. The possible application of this new hybrid filler was explored in preparation of maleated polypropylene (PP- g-MA)/GO-SiO2 composites. The microstructure and interface enhancement of the prepared composites were analyzed by SEM, TEM, OM, TGA, FTIR, and DMA measurements. A uniform dispersion of GO-SiO2 hybrids, enhanced interfacial adhesion and improved mechanical property were evidenced. The reason might be that graphene oxide can be covalently assembled onto the amino-modified silica surface, and simultaneously it provides strong interaction with the PP- g-MA due to similar polarity or possible hydrogen bonding. This work suggests a potential application of graphene oxide-encapsulated particle in preparation of high performance polymer composites. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Interfacial interaction plays a key role in the preparation of high performance polymer composites. In this work, in order to explore the possibility to enhance the interfacial interaction via interfacial crystallization of polymer matrix onto the filler surface, interfacial crystallization structure and mechanical properties of linear low density polyethylene (LLDPE)/whisker composites were investigated. The composites were firstly prepared by melt compounding, followed by processing in both traditional and dynamic injection molding. DSC, WAXD, SEM were used to characterize the interfacial crystallization structure. And the mechanical properties were measured by tensile testing. An imperfect shish-calabash structure, with whisker served as shish, and irregular LLDPE spherulite as imperfect calabash, was formed during common injection molding processing. Such a structure was considered as the main reason for the strong interfacial adhesion and the obviously improved tensile strength and modulus. Furthermore, introducing shear could cause the formation of relatively perfect shish-calabash structure, leading to the stronger interfacial adhesion. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

As part of a continuous effort to develop high performance isotactic polypropylene (iPP) based on β-form crystalline and morphological change induced by rare earth nucleator (WBG), various WBG contents (from 0.025 to 1.0 wt%) were adopted to prepare β-nucleated iPP at a fixed final molten temperature (240°C) in this study. The crystallinity, polymorphic composition, and crystalline morphology were inspected in detail by a series of crystallographic characterizations, including calorimeter, X-ray diffraction, polarized light microscopy (PLM), and electron microscopy. Furthermore, the self-organization and re-crystallization behavior of β-nucleating agent occurred during cooling was characterized by rheometry. Finally, the dependence of mechanical properties, including tensile strength, elongation at break, and impact strength, on WBG content was discussed based on the variations in β-form content and crystalline morphology. Interestingly, it is found that while the WBG content is below 0.1 wt%, the toughness of β-nucleated iPP increases with increase in WBG content due to additional β-form content; as the WBG content is in range of 0.1-0.5 wt%, the toughness increases at a lower rate with increase in WBG content due to β-crystalline morphological change. However, a decrease in toughness is observed while nucleator content is above 0.5 wt% as WBG remains undissolved in iPP upon the adopted processing conditions. The result of this study provides valuable information for potential industrial applications. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A versatile double‐network (DN) hydrogel with two noncovalent crosslinked networks is synthesized by multiple hydrogen bonding (H‐bonding) interactions. The DN hydrogels are synthesized via a heating–cooling photopolymerization process by adding all reactants of agar, N‐acryloyl glycinamide (NAGA) and N‐benzylacrylamide (NBAA) monomers, UV initiators to a single water pot. Poly(N‐acryloyl glycinamide‐co‐N‐benzyl acrylamide) (P(NAGA‐co‐NBAA)) with a triple amide in one side group is synthesized via UV‐light polymerization between NAGA and NBAA, forming a strong intermolecular H‐bonding network. Meanwhile, the intramolecular H‐bonding network is formed between P(NAGA‐co‐NBAA) and agars. The sol–gel phase transition of agars at 86 °C generates the molecular entanglement network. Such a double network enables the hydrogel high self‐healing efficiency (about 95%), good shape memory ability, and high mechanical strength (1.1 MPa). Additionally, the DN hydrogel is completely crosslinked by multiple hydrogen bonds (H‐bonds) and the physical crosslinking of agar without extra potential toxic chemical crosslinker. The DN hydrogels find extensive applications in the biomedical materials due to their excellent biocompatibility. Poly(N‐acryloyl glycinamide‐co‐N‐benzyl acrylamide)/agar double‐network hydrogels crosslinked by multiple hydrogen bonds are synthesized. The double network gives the hydrogel high self‐healing efficiency (about 95%), high mechanical strength (1.1 MPa), and good shape memory ability. [ABSTRACT FROM AUTHOR]