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Medical catheters might cause a high morbidity of catheter-associated urinary tract infections (CAUTIs) because of the bacterial adhesion onto the surface. In addition, the inherent hydrophobicity of catheter materials exacerbates mechanical friction, leading to tissue damage. Therefore, coatings with integrated antibacterial and lubricative properties are appealing approaches to mitigate these challenges. In this study, a kind of polyurethane (PU)-based coatings were developed and prepared on medical catheters, which were modified with a cationic antibacterial agent, quaternized ammonium-modified methyldiethanolamines (QMDEAs). Due to the reaction among castor oil tertiary alcohols, isocyanates and QMDEAs, a polymer cross-linked network was fabricated, in which a hydrophilic polymer, polyvinylpyrrolidone (PVP), was added to form a semi-interpenetrating network. The structures of the coatings were regulated by adjusting the lengths of alkyl chain of QMDEAs, concentrations of pre-coated solutions, ratios of QMDEA:isocyanate, and parameters of preparation process. Among the coatings we prepared, PU-C10–46 possessed the optimized performances, which reduced the dynamic friction coefficient by 91.38 % and had the antibacterial efficiency of 99.9 % with good biocompatibility. The in vivo anti-infective properties of PU-C10–46 were also demonstrated by an infected animal model. Furthermore, PU-C10–46 was produced in an industrial equipment, and the large-scaled industrial products also had the same performances. This work could provide a promising strategy to deal with the challenges of medical catheter-associated infection. [Display omitted] • A strategy to develop a dual-functional coating with contact-killing and lubricative properties were designed. • PU-C10-46 exhibited optimized antibacterial and lubricative performance both in vitro and in vivo. • PU-C10-46 was manufactured using industrial equipment, and the industrial products demonstrated comparable performance. [ABSTRACT FROM AUTHOR]

The utilization of biomass resources for multifunctional bio-based waterborne polyurethane (WPU) development is receiving considerable attention. Phloretin (PRT) is considered to be a potential functional plant-based chain extender due to its unique molecular structure. Hereon, a commercial-grade castor oil-modified polyol was utilized as the soft segment. Through a molecular structure design strategy, PRT was incorporated into WPU skeleton to prepare a series of PWPU coatings with varying PRT contents. The results indicated that the addition of PRT resulted in a reduction in the length of cross-linking sites, an increase in the density of the cross-linking network, and significant enhancement of various properties, including mechanical properties, water resistance, adhesion, and anticorrosive performance. For instance, the PWPU-2 film exhibited a tensile strength of 38.2 MPa and an elongation at break of 608.8 %, while its toughness reached an even more remarkable value of 142.8 MJ/m3, surpassing all previously reported plant oil-based WPU systems. Interestingly, the water absorption rate of the PWPU-4 film decreased to 10.2 %, overcoming the challenge of simultaneously improving both water resistance and mechanical properties in plant oil-based WPU. Furthermore, the protective efficiency (IE) of the PWPU-10 coating reached up to 97.08 %. More importantly, the introduction of PRT had endowed PWPU coatings with a comprehensive range of UV shielding properties. The PWPU coatings prepared in this study have applications in various fields, such as anti-corrosion coatings, sunscreen coatings, and water-based ink connectors. These findings provided theoretical ideas for multifunctional WPU functional coatings. • Phloretin was introduced into castor oil-based WPU network. • The castor oil-based WPU films modified by phloretin exhibited strong toughness. • The castor oil-based WPU exhibited high transparency, and good water resistance. • The castor oil-based WPU showed outstanding UV resistance and anti-corrosion properties. [ABSTRACT FROM AUTHOR]

Wet-weaving and cluster braiding in industrial production processes generate irreversible defects and grooves in carbon fibre (CF) filaments, which reduce the service life and mechanical properties of the fibres. Additionally, the fibre surface covered with numerous inactive carbon-containing groups and presents chemical inertness, which limits the prospects of CF applications. Hence, the hyperbranched bio-based waterborne polyurethanes (SWPU) possessing the synergism of sulfamate and carboxylate complex hydrophilic units were adopted as sizing coatings to improve the flexural and tensile strengths of CF, as well as fibre surface roughness and wettability. The SWPU is designed on dihydroxymethylbutyric acid and sulfamates (A95) as per- and post-chain extenders, respectively, trimethylolpropane (TMP) as an intramolecular cross-linker, and plant-extracts castor oil (CO) replacing petroleum-based petrochemicals as the soft-segments. The construction of CO-TMP hyperbranched cross-linking networks and the strengthened hydrogen-bonding effects of the polar sulfamates positively affect the intermolecular interactions and configuration stability of SWPU sizing coatings. SWPU revealed favourable thermo-mechanical properties achieving a T5% decomposition temperature and toughness of 297.83 °C and 35.24 MJ/m3. The coating effects of the bio-based sizing agents not only repaired defects and improved surface roughness on CF, but the polar groups in SWPU comprising SO 3 Na, carbamate and polyurea promoted the chemotactic activity and wettability of the fibres. The surface energy and tensile strength of the SWPU sized CF reached 43.75 mN/m and 5.68 GPa, respectively, which were 45.4 % and 30.7 % higher compared to original CF. The research contributes to the development and industrial production of high-performance, eco-friendly bio-based sizing coatings. • Hyperbranched bio-based waterborne polyurethane sizing coatings • Synergism between carboxylate pre- and sulfamate post-chain extenders • Cross-linking networks and SO 3 Na-enhanced hydrogen-bonding • Emulsion characteristics and thermodynamic properties of sizing coatings • Surface energy, roughness, wettability and tensile strength of sized carbon fibres [ABSTRACT FROM AUTHOR]

Liquid-repellent fabrics have attracted significant attention due to their resistance to hazardous chemicals and reduced maintenance cost. Traditionally, Poly-Perfluoroalkyl substances (PFAS) have been widely used due to their intrinsic low surface energy, which renders them omniphobic (oil and water-repellent) properties. However, due to health hazard issues, there is a growing movement to phase out PFAS use in consumer and industrial products. Recent studies showed that coating low-surface tension flexible brushes to a flat glass substrate, results in the formation of liquid-like slippery surfaces, which impart repellency to various liquids. In this study, two PFAS-free liquid-like coatings were covalently attached to the porous, rough surface of cotton fabric: long alkyl chain silanes, and a hydrolysable trimethoxy silyl polydimethylsiloxane (TMS-PDMS). PDMS is non-toxic, biocompatible, and cost-effective. Importantly, it provides low surface energy of approximately 20 mN/m and has the added benefit of a very low glass transition temperature (T g = −127 °C), creating a highly smooth structure on the surface. Long alkyl chain silanes also feature low surface energy and flexible brush structures that offer a slippery surface. Silanes with different carbon chain lengths and PDMS brushes with different molecular weights were evaluated. PDMS-treated fabric with MW = 3600 g/mol (F-3600) and fabric treated with n-dodecyl triethoxy silane (F C12) showed superhydrophobic properties with a water contact angle>150° and oil repellency to castor oil with contact angle>80°. The mechanical properties of the PDMS-treated fabrics were comparable or even superior to the control sample. Using a novel toxicity assessment method (P2OAsys), linear PDMS demonstrated a moderate toxicity score of 4.5, in contrast to silanes, with a high toxicity score > 6, and PFAS>8. • Novel PFAS-free omniphobic fabric coatings are compared: long-chain silane and PDMS • The coatings have facile application methods and maintain mechanical properties • Durable liquid-like brushes on fabric show omniphobicity and alcohol repellency • Coated fabrics exhibit liquid-repellency even after abrasion and washing cycles • Both omniphobic coatings were less toxic than PFAS (P2OAsys toxicity assessment) [ABSTRACT FROM AUTHOR]

Urea coated with only sulfur is prone to cracking and exhibits poor controlled-release characteristics. Conversely, employing polymers as the sole coating material is expensive and not easily biodegradable. To address these challenges, polysulfide castor oil–based polyols with varying sulfur contents (PSOPs-30 %, PSOPs-40 %, PSOPs-50 %, and PSOPs-60 %) were successfully synthesized using a simple chemical process. This process utilized castor oil and elemental sulfur as primary raw materials. Subsequently, PSOPs-30 % and PSOPs-40 % were cured to form films (P-30 % and P-40 %) and coated urea (PSCUF-30 % and PSCUF-40 %). The synthesis process, mechanism, and physical and chemical properties of PSOPs revealed that the amount of sulfur involved in polymerization was not proportional to the initial amount of sulfur added. The structure and thermal stability of PSOPs were characterized using Fourier-transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR), and thermogravimetric analysis (TGA). Minor variations in crosslinking degree and sulfur content between P-30 % and P-40 % caused some differences in mechanical properties, shore hardness, water absorption, and water contact angles. TG-FTIR analysis of P-30 % and P-40 % indicated the generation of carbonyl sulfide throughout the process, predominantly in the early stage and very few in the later stage. The cumulative nitrogen release times for PSCUF-40 %–7.0 % and PSCUF-30 %–7.0 % were 50 and 60 days, respectively. In terms of degradability, whether in distilled water or NaOH solution with pH 8, the degradation rate of P-40 % was higher than that of P-30 %, reaching 6.55 % and 6.92 % over 70 days. In addition, methyl ricinoleic (MCO) was utilized as a polyol to prepare PCUF-MCO for comparative analysis. • Polysulfide castor oil-based polyols with a low cost were prepared using castor oil and elemental sulfur. • The film has the advantages of low cost, good mechanical properties, low water absorption, and good thermal stability. • Degradation rate reached 6.92 % for 70 days in NaOH solution. • The cumulative nitrogen release time of coated urea was more than 60 days. [ABSTRACT FROM AUTHOR]

The mechanical properties and water resistance of castor oil-based waterborne polyurethane are mutually limited due to the presence of a hydrophilic chain extender. Herein, Arbutin (AT) was used as a crosslinking agent, and benzimidazole (CR-455) was utilized as an ultraviolet absorber, sustainable long fatty hydrophobic chain extenders, sorbitan monooleate (SP), glycerol laurate (GML), glycerin monostearate (GMS), and trimethylolpropane monooleate (TPM), were introduced into castor oil-based waterborne polyurethane (CWPU) backbones through molecular structure design respectively. Subsequently, the amount of SP was changed to prepare a series of waterborne polyurethane dispersions, and their emulsion and film properties were thoroughly investigated. The finding showed that the incorporation of long fatty hydrophobic chain extenders led to an increase in crosslinking density, thereby endowing CWPU films with good mechanical properties, water resistance, and anti-corrosion efficacy. Moreover, the bio-based content in the CWPU film had reached an impressive 90.9 %. The addition of SP content resulted in a gradual improvement in the mechanical properties, water resistance, and corrosion resistance of CWPU-SP films. When the SP content was 40 %, due to the high strength of hydrogen bonds and the density of crosslinking in systems, the tensile strength, toughness, water absorption rate, and corrosion protection efficiency of the CWPU-SP40 film reached 18.1 MPa, 20 MJ/m3,7.7 %, and 98.47 %, respectively. Particularly, the prepared transparent CWPU films exhibited complete UV shielding. This work would pave the way for the application of bio-based waterborne polyurethanes in high-performance coatings, such as anti-corrosion and sunscreen. [Display omitted] • A novel multifunctional highly crosslinked bio-based WPU networks were successfully prepared. • Various types of long fatty hydrophobic chain extenders were incorporated into the molecular chain of bio-based WPU. • The bio-based WPU films showed the mechanical performance and water resistance. • The prepared bio-based WPU films possessed good UV resistance and corrosion resistance. [ABSTRACT FROM AUTHOR]

Castor oil-based polyols with high OH values are synthesized through the low odor thiol-ene reaction and then are used for preparing UV-curable acrylate-urethane resins (AUCORs). The structure of the AUCORs is confirmed by 1H NMR and IR. The AUCORs based resins containing diluents can rapidly form cured films under UV light irradiation in air, with a very high gel ratio of over 95 %. The UV-curing dynamics shows that polymerization rate and final acrylate conversion under the N 2 atmosphere both depend on C C bond content, but they are reduced under air due to oxygen inhibition effect. All the cured films have good heat stability with an initial decomposition temperature over 300 °C. The cured films can display different T g within the region of 55–85 °C depending on the crosslink density tuned by the acrylate/urethane content. The urethane content/diluter can affect some general properties of the coating films, for instance water absorption ability, wettability, hardness and adhesion force. Interestingly, the cured films have a very good light transmittance in the visible light region, as high as that of glass slides. • New castor oil-based polyols with high OH values were easily synthesized by an eco-friendly method. • UV-curable acrylate-urethane resins can be rapidly prepared by the castor oil-based polyols. • The AUCORs resins show the acrylate/urethane dependent UV curing dynamics and properties. • The AUCORs resins can form extremely transparent films under UV irradiation. [ABSTRACT FROM AUTHOR]

Fire safety of polyurethanes (PUs) has limited their further practical applications. To address this problem, we designed novel phosphorus-based flame retardants (P-FR) by incorporating aryl (Ar) groups via Kabachnik–Fields reaction, realizing π–π interaction-reinforced Ar2 and Ar5. Total heat release and peak heat release rate of PU/Ar5, whose flame-retardancy-index of 5.02 due to reduced combustion time, decreased 23.24 and 9.23 %, respectively, compared with neat PU. Moreover, UL94 rating for PU/Ar5 was improved from V-2 to V-0. These results demonstrate that Ar5 effectively generate a barrier effect that blocks oxygen, fuel, and heat. Sluggish mobility and phase transition are responsible for such enhancement due to a delay effect with the existence of π–π interactions and steric hindrance. Encouragingly, tensile strength and toughness of PU/Ar5 were greatly improved by 1345.8 and 670.3 %, respectively, compared with neat PU. We believe that this study could provide a promising method for introducing specific function to flame retardants to enhance fire safety and mechanical properties of composites. [Display omitted] • Ar–P–N flame retardant (Ar5) was synthesized using Kabachnik–Fields reaction. • Synergetic effects of Ar5 and flame retardancy mechanism of aryl were identified. • Flame retardancy index of PU/Ar5 increased due to the reduced combustion time. • PU/Ar5 composite exhibited significantly improved tensile strength and toughness. • Modified-flame retardancy index was introduced with time-to-extinction factor. [ABSTRACT FROM AUTHOR]

A novel ambient-cured coating film obtained via a Knoevenagel and Michael addition reaction between modified acetoacetylated castor oil and a crosslinker that contains both aldehyde and acrylate groups was developed. Compared to coating films obtained via Knoevenagel addition and Michael addition reactions, the Knoevenagel and Michael addition reaction coating film has a good balance of properties. • A novel ambient-cured coating film obtained using a Knoevenagel and Michael addition reaction was investigated. • The modified acetoacetylated castor oil was characterized by NMR, FTIR, and viscosity analyses. • The properties of Knoevenagel and Michael addition reaction coating films was discussed. A novel ambient-cured coating film obtained via a Knoevenagel and Michael addition reactions between modified acetoacetylated castor oil and a crosslinker that contain both aldehyde and acrylate groups was developed. The modified acetoacetylated castor oil was synthesized via thiol-ene coupling and transesterification reactions and was characterized by NMR, FTIR, and viscosity analyses. The coating films prepared by the Knoevenagel addition reaction, Michael addition reaction, and Knoevenagel and Michael addition reactions coating film are discussed. The tensile and thermal properties of the obtained coating films were investigated by dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results demonstrated that the Knoevenagel and Michael addition reactions coating film has a good balance of properties. Moreover, we also prepared films with different crosslinkers by Knoevenagel and Michael addition reactions and found that the films have good properties, including glass transition temperature (41%–54%), pencil hardness (3 H), and tensile properties (1.17 MPa – 2.23 MPa). Overall, the film made via Knoevenagel-Michael addition technology provides an excellent bio-based coating system. [ABSTRACT FROM AUTHOR]

A novel Michael addition reaction coating based on an acetoacetate-modified castor oil prepared by a thiol-ene coupling reaction and transesterification reaction was created, which had improved mechanical properties due to the structural properties resulting from the acetoacetate ratio of modified acetoacetylated castor oil. • We report a Michael addition reaction coating based on a acetoacetate-modified castor oil. • The acetoacetate-modified castor oil was prepared by a thiol-ene coupling reaction and transesterification reaction. • The coating films were prepared from an acetoacetate-modified castor oil and a 4,4-diaminecyclohexylmethane. • The mechanical properties were noticeably improved. The Michael addition reaction was used to create ambient curable film materials based on an acetoacetate-modified castor oil, and a multifunctional alamine was prepared. The thiol-ene coupling reaction could change the proportion of hydroxyl groups in the castor oil, thereby improving the crosslinking density and mechanical properties of the coating films. The acetoacetate-modified castor oil was achieved in two steps. First, the C C bonds of castor oil were coupled using a thiol-ene coupling reaction, which has a high conversion rate and few by-products. Second, acetoacetate-modified castor oil was prepared by a transesterification reaction between tert-butyl acetoacetate and modified castor oil. The acetoacetate-modified castor oil was characterized by Nuclear magnetic resonance (NMR), Fourier Transform infrared spectroscopy (FTIR), Gel Permeation Chromatography (GPC) and viscosity measurements. Finally, coating films were prepared from the acetoacetate-modified castor oil and 4,4-diaminecyclohexylmethane via a Michael addition reaction at room temperature (25 °C). The mechanical properties were noticeably improved compared to those of the unmodified castor oil film. The tensile properties increased from 0.68 MPa to 1.76 MPa, and the glass transition temperature (T g) increased by approximately 30 °C. [ABSTRACT FROM AUTHOR]

• A series of the thiol-ene UV-curable coatings based on a castor oil-based hyperbranched urethane acrylate were prepared. • Films with high optical transparent, excellent flexibility and water resistance were obtained via thiol-ene click reaction. • As more tetrathiol monomer was added, the double bond conversion of the thiol-ene system increased. • The ability to tune the flexibility makes these thiol-ene based materials suitable for application in flexible coatings. Thiol-ene click reactions are more oxygen tolerant alternative to the conventional (meth)acrylate chemistry that is frequently used for the rapid production of photopolymerized networks with numerous desirable properties. To attain a high curing efficiency while maintaining the advantages of thiol-ene systems, a castor oil-based hyperbranched urethane acrylate was employed in this work as a primary oligomer for UV-curable coating formulation. Subsequently, a tetrathiol monomer (PETMP) was introduced into the coating formulation to obtain a thiol-ene system. The effects of PETMP loadings on the UV-curing kinetics and final polymer properties were systematically investigated. Consequently, thiol-ene based films with excellent flexibility and water resistance were obtained as a result of the high efficient thiol-ene photopolymerization. The double bond conversion of the thiol-ene system was found to increase with the addition of more PETMP. Impressively, with the incorporation of 5 wt% PETMP, the resultant UV-cured film had the best acid resistance and exhibited a double bond conversion of 93.6%, a pencil hardness of 6H, a water absorption of 0.76%. Additionally, all of the prepared films were completely transparent and possessed good microstructures. These thiol-ene based films may provide insight into the preparation of high-performance UV-curable coatings with excellent flexibility. [ABSTRACT FROM AUTHOR]

• Sulfur and nitrogen containing biobased polyol has been synthesized from undecylenic acid. • A polyol containing phosphate group has been prepared form cardanol. • Biobased polyol and phosphorous containing cardanol based polyol combinedly used for the preparation of polyurethanes. • An improved mechanical and anti-corrosion properties have been observed for the prepared polyurethanes. Renewable resource based polyol derived from undecylenic acid, a by-product of castor oil, was successfully synthesized by three consecutive reactions: methylation, thiol-ene addition, and amidation. The biobased polyol is a sulfur- and nitrogen-containing polyol. The structure was confirmed by FTIR, NMR, and mass spectroscopic techniques. The undecylenic acid based polyol was used as a polyol along with phosphated cardanol-based polyol in the preparation of polyurethane coatings. The obtained polyurethanes were assessed for their properties by various techniques such as thermogravimetric analysis (TGA), dynamic mechanical and thermal analysis (DMTA), Universal testing machine (UTM) and electrochemical study. Interestingly, the biobased polyol improved mechanical property such as toughness of the material when it was incorporated in different weight percentages to the phosphated cardanol-based polyol. Moreover, the synergistic effect of the phosphorous and biobased polyol with the elements - sulfur and nitrogen, enhanced the anti-corrosion and antimicrobial natures of the polyurethane coating. The corrosion rate was drastically decreased from 3.0 × 10–4 to 1.8 × 10–7 mm per year for the prepared polyurethane coatings. [ABSTRACT FROM AUTHOR]

• Synthesized soft polyurethane coatings based on natural source-derived polyols. • Castor oil was epoxidized in the presence of ECO Al and ECO F catalysts. • Conversion of double bond to oxirane were 96 and 74% for ECO Al and ECO F. • Water-based polyurethane with 40 wt.% polyol had minimum particle size and PDI. Water-based polyurethane coatings give a soft feeling for surface engineering for advanced wear- and friction-resisted purposes. In this work, we synthesized three types of polyols from castor oil applying short- and high-efficiency method for potential soft coating uses, as an appropriate alternative for methods that use a rotary evaporation and a vacuum oven in polyol synthesis. Castor oil was epoxidized in the presence of two types of catalysts, i.e. γ-alumina (ECO Al) and formic acid (ECO F). Although we could not detect unwelcome reactions taking place in the reaction chamber that should reduce the content of oxirane oxygen, the relative percentages of double bond conversion to oxiran for ECO Al and ECO F were theoretically 96% and 74%, respectively. Ring opening reaction of ECO Al was performed by two types of saponified castor oil utilizing Dean–Stark trap, an appropriate alternative for methods that use a rotary evaporation and a vacuum oven in polyol synthesis. The synthesized polyols were characterized by FTIR (ATR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), viscometer and OH number evaluation. Different weight percentages of the polyol samples having Tg values of ca. -6.5 °C and OH number of 6.2 were applied in synthesis of water-based polyurethane (WPU). It was found that WPU with 40 wt.% polyol has a minimum particle size and minimum poly dispersity index. WPU with 60 wt.% polyol exhibited the highest molecular weight, while it had the lowest viscosity, water absorption, glossiness, hardness, adhesion and Tg. By such structural manipulations we provided a basis for enhancement of properties of coatings for future works. [ABSTRACT FROM AUTHOR]

• One-pot synthesis of castor and tung oil-based polyurethane-imides was developed. • The introduction of Diels-Alder adducts notably increases the mechanical properties. • The thermal stability improves with the incorporation of imide groups. • The resulting polymers have high bio-renewable content. Herein, castor and tung oil-based polyurethane-imides with tailored thermal and mechanical performance were developed by a one-pot method. First, tung oil (TO) was transformed into eleostearic acid diethanol amide (EADEA) by methyl-esterification and amidation. The resulting EADEA was then mixed with castor oil (CO), N -(2-hydroxyethyl)-maleimide (HEMI) and isophorone diisocyanate to prepare biobased polyurethane-imides. The formation of Diels-Alder (DA) adducts from EADEA and HEMI during the curing process was determined by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). The effect of DA adducts contents on the thermal and mechanical properties of corresponding polymers was investigated. The results show that the introduction of TO-maleimide DA adducts significantly increases the glass transition temperature, tensile strength, Young's modulus and gel content of the resulting polyurethanes. The highest tensile strength of the resulting polymers can reach 48.2 MPa. Besides, the thermal stability was also improved with the incorporation of imide groups. This technique reported here demonstrates several advantages, such as one-pot synthesis, high bio-renewable content, low cost and tunable performance, and it is promising to find application in coatings, adhesives and so on. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Novel industrially relevant flame retardant self-curable WPUs were synthesized. • Reactive-type phosphorus flame retardant diol (Exolit® OP560) was used to synthesize WPUs. • Bio-based polyol (castor oil) was added to the formulation to increase water resistance. • High flame retardancy was due to integral char formation and gas dilution effect. Abstract A series of novel industrially relevant halogen-free flame retardant self-curable silanized waterborne polyurethane (WPU) coatings were successfully synthesized. The effect of reactive-type phosphorus flame retardant diol (Exolit® OP560) incorporation into PU structure was investigated. High limit oxygen index (LOI) value of 30.4% accompanied by V0 classification of UL-94 vertical burning test confirmed promising flame retardancy of the WPU film containing 8.7 wt% OP560. Furthermore, microscale combustion calorimeter (MCC) indicated the obvious decrease in the heat release rate (HRR), the temperature of maximum HRR, total HR, and HR capacity (HRC) of WPUs by adding phosphorus diol. TGA, SEM, MCC, and TG-IR studies revealed that great improvement in flame retardancy was due to not only integral char formation through the synergistic effect of phosphorus and silicon but also gas dilution effect. Moreover, bio-based polyol (castor oil) was added to the formulation to increase water contact angle and water resistance. High flame retardancy and enhanced mechanical properties make this formulation highly relevant for industrial applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Alkyd was synthesized from the Bio-resource (castor oil). • Coating was made by incorporation of synthesized alkyd into the melamine-formaldehyde resin. • Various coating properties were studied and discussed including thermal, mechanical and anticorrosion. • Anticorrosive performance was improved with the incorporation of alkyd. Abstract The legislation pertaining to air pollution has led the paint and coating industries to develop ways to reduce the volatile organic content (VOC) of the solvent-borne coatings without compromising the film performance and application characteristics. This resulted in the emergence of solvent-free alkyd coatings which are the most potential solutions to reduce environmental problems. In the present work, hydroxyl functional castor alkyd (CA) was synthesized using a solvent-free process and cured with Melamine Formaldehyde (MF) resin. Structures of the formed product were confirmed by Fourier Transform Infrared (FTIR) spectroscopy and 1H and 13C Nuclear Magnetic Resonance (NMR) analysis. Thermal properties of the cured film samples were determined using Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) analysis which showed that Tg and degradation temperature values increased as the amount of MF increased. Also, the corrosion performance of the coating films was studied by using a salt spray test which revealed that the best corrosion resistance was shown by 70:30 ratio of MF: CA. All the results including mechanical properties of the coating film showed that the eminent role was played by the MF in the performance of CA. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Carbon Nano Particles (CNP) prepared from the leaves of Eucalyptus globulus. • The functionalized CNPs are used in castor based PU coatings. • The CNPs and PU coatings were characterized. • The synthesized PU-CNP coatings shows the improved properties. Abstract The usability of nanomaterials in various research endeavour has been on the front. burner in the past few decades. This is due to its high aspect ratio and steep electrical, molecular defined structure, mechanical and physical properties. This present study reports the synthesis of carbon nanomaterials (CNM) from Eucalyptus globulus leaves. Fresh green leaves of Eucalyptus globulus were collected and dried under the sun. The dried brown leaves were later incinerated completely under atmospheric oxygen. Obtained ashes were treated with acid piranha solution in other to modify the peripheral of the ashes with carboxyl groups (CNM-COOH). Scanning electron microscopy image divulges the presence of carbon nanorods in the ash. CNM-COOH materials in percentages were then incorporated within the polyurethane polymer matrix of which Castor seed oil (Ricinus communis) and trimethylopropane (TMP) provided the hydroxyl base for urethanation. Infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis was used to confirm material modification. Synthesized urethane composites of CNM-COOH material shows improved thermal, mechanical, hydrophobicity and anticorrosion properties when compared with that of pristine polyurethane (PU). [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • An ambient temperature curable coating based on the Knoevenagel condensation was developed. • The coatings had a high gloss, a high transparency. • Different aromatic dicarboxaldehyde cross-linkers can be used to prepare films. • Characterized the mechanical and thermal properties of these films. Abstract Using a Knoevenagel condensation cross-linking technique, we developed new ambient curable coatings based on acetoacetylated castor oil. The acetoacetylated castor oil was synthesized via the reaction of castor oil with t -butyl acetoacetate, and the films were cured at ambient temperatures (25°C) using aromatic dicarboxaldehydes as crosslinkers. In this article, we optimized the curing conditions of the coating and found that a ratio of acetoacetylated castor oil to dicarboxaldehyde groups of 1:0.75 and a catalyst loading of 7.5 wt % provided an appropriate curing time and the coating with the best performance. Moreover, we prepared films with different aromatic dicarboxaldehyde cross-linkers and characterized the mechanical and thermal properties of these films. [ABSTRACT FROM AUTHOR]

Biobased thermosetting polymers have attracted interest owing to their renewable source materials, long service life, and properties comparable to those of petroleum-based materials. However, the fabrication of those that merge exquisite mechanical properties with fast self-healing performance has not been demonstrated to date. In this work, a biobased polyurethane coating was constructed using curcumin dioxime (CD), castor oil (CO), and isophorone diisocyanate (IPDI) to fulfill these features. The biobased CD monomer was prepared using curcumin and hydroxylamine hydrochloride and confirmed by nuclear magnetic resonance, flourier-transform infrared (FT-IR) spectra, and high-resolution mass spectrometry (HR-MS). To investigate the correlation between the mechanical properties and self-healing performance, a series of polyurethane coatings were fabricated by varying the ratio of CO to CD. The results showed that the crosslinking density (v e), glass transition temperature (T g), and Young modulus of these coatings increased with the decrease in the ratio of CO to CD, leading to tunable mechanical properties. In particular, the tensile strength and elongation of the COPU-4 coating were as high as 17.2 MPa and 295 %, respectively. The stress relaxation experiments revealed that these coatings exhibited low activation energy (E a), as low as 28.3 kJ/mol for COPU-5. Besides, all COPU-X coatings demonstrated self-healing efficiency higher than 71 % within 1 min at 90 °C, and some of them even reached >90 % after 8 min. The results demonstrate the promising tunable mechanical and excellent self-healing properties of these novel biobased polyurethane coatings and pave the way for the development of bioderived sustainable thermosetting polymers. [Display omitted] • A fully biobased CAN was fabricated using curcumin dioxime (CD) and castor oil (CO). • The CD/CO ratio was varied to investigate the relationship between mechanical properties and self-healing performance. • All the synthetic polyurethane coatings displayed impressive self-healing efficiency of >71 % in only 1 min at 90 °C. [ABSTRACT FROM AUTHOR]

Oil-repellency of fabric is essentially based on perfluoroalkyl substances (PFAS, or called perfluorochemicals (PFCs)). However, plans to phase out the use of these chemicals, even those short-chain ones (C4-C6), have been announced because they accumulate in the human body and are extremely persistent in the environment. It is urgent to develop non-fluorine surface chemistry for oil-repellent fabric finishing. Here, we report the non-fluorine oil repellency of brush-like polydimethylsiloxane (PDMS) coating (g-PDMS), and the comparison of its oil repellency with that of a common PFAS crosslink polysiloxane coating (C 4 -PFAS). A catalyst-free, solvent-free chemical vapor deposition (CVD) process was used to prepare the g-PDMS coating. For smooth glass, g-PDMS coating exhibits ultralow contact angle hysteresis (∆ θ) for various oils (1.3–7.3°), while the ∆ θ of C 4 -PFAS coating is much higher (30.7–49.7°). For fabrics, g-PDMS and C 4 -PFAS achieved almost the same contact angles to castor oil (~134°). According to GB/T 19977-2014 standard, the oil repellency of coated fabrics was rated Grade 5 for both g-PDMS and C 4 -PFAS. Therefore, the non-fluorine oil repellency of g-PDMS is able to meet the basic requirement of oil-repellent fabric finishing, and it is expected that the oil repellency can be further improved by the rational design on surface topography. A linear polysiloxane brush coating shows the same oil repellency grade as that of a crosslink C4-fluorinated polysiloxane coating (Grade 5, GB/T 19977-2014 standard). [Display omitted] • For fabric, g-PDMS shows the same oil repellency grade as C 4 -PFAS, according to GB/T 19977-2014 standard. • For fabric, g-PDMS and C 4 -PFAS show almost the same contact angle to castor oil (~134°). • For smooth glass, g-PDMS shows much lower oil contact angle hysteresis (∆ θ) (1.3–7.3°) than C 4 -PFAS (30.7–49.7°). • Surface energy of g-PDMS (24.7 mN/m) is slightly higher than that of C 4 -PFAS (22.3 mN/m). [ABSTRACT FROM AUTHOR]

In last decade study on anticorrosive performance of hyperbranched polymer nanocomposites attracted the overwhelming attention of researchers. However, scanty work on oleo hyperbranched polymer coatings are reported in the literature, while no work has been reported on castor oil-TiO 2 nanoparticle dispersed hyperbranched poly (ester amide) nanocomposite coatings. Thus, herein we report the synthesis and performance of TiO 2 nanoparticle dispersed hyperbranched poly (ester amide) nanocomposite coatings on Physico-mechanical and anticorrosive coatings on carbon steel in 3.5 wt. % HCl, NaCl and NaOH solutions. The synthesis of hyperbranched polymer is based on the simple A 2 +B 3 polycondensation reaction. The structural elucidations of these were done using FTIR and NMR ( 1 H and 13 C) spectroscopy while the physico-mechanical tests were conducted by standard ASTM methods. The electrochemical corrosion techniques such as open circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy and salt spray tests were used to analyse the anticorrosive activity of these coatings. These studies revealed that the TiO 2 dispersed hyperbranched poly (ester amide) coatings exhibit far superior physico-mechanical, hydrophobic (contact angle values from 98° to 107°) and anticorrosive properties (i corr 9.89 × 10 −7 Acm -2 , E corr -0.192 V, impedance ∼ 10 5   Ω  cm 2 , phase angle 77° and R pore 3.7 × 10 6 ) than those of hyperbranched poly (ester amide) and other such earlier reported coating systems. [ABSTRACT FROM AUTHOR]

A new polyfunctional acrylate monomer (COPERAA) was synthesized from castor oil and utilized as a sustainable reactive diluent for UV-curable materials. Firstly, experimental conditions for the synthesis of the monomer were optimized and its chemical structures were confirmed by FT-IR, 1 H NMR, and ESI–MS. Subsequently, the effect of COPERAA on biobased content, viscosity, and volumetric shrinkage of the obtained AESO resins were studied. After that the effect of COPERAA on thermal, mechanical, coating, and swelling properties of the resulting UV-cured bioresins were investigated. Furthermore, UV-curing behaviors of the resultant bioresins were evaluated by real-time IR. Compared with the petroleum-based trimethylolpropane triacrylate (TMPTA) diluent, the biobased COPERAA diluent showed better performance on the biobased content, volumetric shrinkage, adhesion, and final C C conversions of the resulting AESO materials and better compatibility with the AESO prepolymer. Therefore, the developed oil-based diluent shows promise to be applied in UV-curable materials. [ABSTRACT FROM AUTHOR]

Castor oil (CO) and dehydrated castor oil (DCO) were used for the synthesis of new alkyd-urethane resins via a two-stage process: synthesis of the alkyd resin flowed by urethanization. 1HNMR and FTIR analyses showed that the synthesized DCO and CO alkyd resins still have a large amount of hydroxyl groups that make then useful as polyols for the further urethane linkages. FTIR analyses confirmed the formation of the urethane bonds when the previous alkyd resins reacted with isophorone diisocyanate. The cured films from both alkyd-urethane resins exhibited similar hardness, adhesion, chemical and water resistance, and gloss. Gouge hardness and scratch hardness were 3H and 4H, respectively. The adhesion of both films was good. Cured films were resistant to water, xylene and H 2 SO 4 , but they were slightly affected by NaOH and strongly affected by acetone. The films exhibited significantly high gloss values (120.1 at 60°), associated with the urethane linkages. DCO resin showed lower drying times than those of CO resin and the addition of dryers diminished these times, indicating a strong contribution of double bonds on the drying. Acetone as solvent further improved the drying times due to a better mobility of the molecules. Drying of the resin is due to the formation of more urethane linkages andto the double-bond curing by air-oxidation. A higher synthesis temperature favors the formation of urethane linkages, making the resin more rigid and this hinders the final double-bond curing. Drying times significantly decreased by increasing the drying temperature from 25 to 100 °C. TGA indicated that the cured films were stable up to 220 °C. [Display omitted] • New alkyd-urethane resins from castor oil and dehydrated castor oil • Both resins exhibited similar coating performances. • Cured films exhibited significantly high gloss value of 120.1 at 60°. • There is a strong contribution of double bonds on the drying. • Acetone as solvent further improved the drying times. • Drying time remarkably decreased by increasing the drying temperature. [ABSTRACT FROM AUTHOR]

In this work, a novel vegetable oil-based polymers were prepared by epoxidation of soybean oil (SBO) and castor oil (CO) followed by ring opening reaction of epoxidized oil with polyether amine and poly propylene glycol. The prepared polymers were characterized by FTIR and GPC. The properties of vegetable oils and epoxidized vegetable oil (EVO) were studied. The prepared polymers were employed as novel polymeric dispersants for pigment dispersion in solvent based printing ink application. The mechanical and optical properties of prepared ink were studied. The net technical properties of the new ink formulations are relatively comparable to the prepared printing ink from standard polymeric dispersant. The polymeric dispersant 2 (PD2) and polymeric dispersant 4 (PD4) gave the best optical and mechanical properties among the prepared polymers. [ABSTRACT FROM AUTHOR]

Two bio-based organophosphorus-containing epoxy curing agents (MMDOPO and MAPDGR) with different rigid or flexible characteristics were synthesized from myrcene and castor oil, respectively. Their molecular structures were characterized by Fourier transform infrared spectroscopy (FTIR), 1 H and 31 P nuclear magnetic resonance ( 1 HNMR). Then they were mixed at different weight ratios to form new curing agents for epoxy resin (E-51). Results show the tensile and flexural strength of the cured epoxy materials first increase and then decrease with the increase of MMDOPO content. Dynamic mechanical analysis (DMA) shows the glass transition temperature (T g ) rises significantly with the increase of MMDOPO content. The material’s thermal stability and flame retardant properties were also investigated. The initial decomposition temperature (T i ) and limiting oxygen index (LOI) both are elevated while the residue decreases with the increase of MMDOPO content. When the MMDOPO/MAPDGR weight ratio is 25/75, the mechanical properties are relatively balanced with a high elongation at break of 160.8% and a moderate tensile strength of 9.95 MPa, and bending test indicates that the sample exhibits a flexible failure behavior with a yielding point. [ABSTRACT FROM AUTHOR]

Novel biobased poly(ester-urethane)s (PUDs) were synthesized by solvent free homogeneous solution polymerization of poly(caprolactone) diol (PCL), castor oil-based polyols (COLs), dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI) and 1,4-butane diol (BD) as the chain extender. The polyurethane dispersions were prepared by adding required amount of triethylamine (TEA) and water. In this work, castor oil-based polyols have been synthesized using the depolymerized oligoester obtained from glycolysis of PET waste with poly(ethylene glycol) (PEG 400) and castor oil. The effects of the soft segments content on the thermal and coatings properties of resulting polyurethane films have been examined by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and measurement of the coatings properties. Phase separation of polyurethane shows a strong correlation with crystallization behaviour of the polyurethane prepared. It is established that all PUD samples containing PCL as a part soft segment with different molar ratio of castor-oil polyol are crystallisable polymers. The results from XRD analysis have showed that highest degree of crystallinity (23 and 22%) is reached in polyurethanes based on the largest content PCL diol (CPU77 and CPU73). The thermal stability of samples based on (COL/PCL molar ratio 0.25:0.75) possesses the best thermal properties but less values hardness coatings which can be ascribed to a decrease of the hard segment i.e. DMPA content in polyurethane dispersions. The long-term stability of polyurethane dispersions has been investigated using UV–vis spectroscopy. The physico-mechanical properties such as hardness adhesion test and gloss of the dried films have also been determined considering the effect of soft segment content on coating properties. [ABSTRACT FROM AUTHOR]

Although controlled-release fertilizer (CRF) is a safer and more efficient strategy to administer nutrients for plant growth, it is still a daunting task to reduce the cost and improve the degradability of the synthetic resin coatings. In this paper, an inorganic/organic composite coating for urea fertilizer was prepared from a biodegradable castor oil-based polyurethane (PU) filled with the layered Na-bentonite (Na-BT), which was ultrasonically treated by a series of green PEG surfactants. Synergistically influenced by various intercalation ability, cation-hosting ability and hydrophilicity of the PEGs, the porous structures of the modified Na-BT (MBT) fillers were simply tuned by varying the Mn molecular weights of the PEGs, resulting in the adjustable water swelling and mechanical properties of the MBT/PU composites. Moreover, it was confirmed that the water swelling property played a critical role in controlling the early stage of nutrient release, and the mechanical properties were important for the longevity of nutrient release from the CRFs. The best MBT/PU composite supported a CRF with a long-term release of 75 % in 38 days, which was much longer than the one based on pure PU (20 days). The porous structures of the modified Na-BT (MBT) samples were tuned under the synergistic effects of PEG-intercalation interaction, particle surface charge and water replacement, which promoted the intrusion of the mixture precursor of TDI and castor oil into the internal pores of the MBT filler. After coating on the urea granules, the comprehensive performance of the coating fertilizer can be enhanced due to the improved interfacial interactions. [Display omitted] • Green modification, structure control and investigation of Na-bentonite via PEGs • The effects of PEG-intercalation, particle surface charge and water replacement • Improving water absorbency and mechanical properties of composite film • Optimizing controlled-release performance of coated fertilizer [ABSTRACT FROM AUTHOR]

Halogenated flame retardants are under regulatory scrutiny despite their outstanding flame retardancy. The present study focuses on the development of non-halogenated flame retardant and corrosion-resistant polyurethane coatings from castor oil. Towards this attempt, a non-halogenated, hydroxy functionalized, triazole and phosphorus-containing reactive flame retardant (HTP-FR) with anti-corrosive properties was designed and synthesized by azide-alkyne cycloaddition of 2-azidoethanol, and Diphenyl prop-2-yn-1-yl phosphate. By adding HTP-FR to castor oil in 50 and 100 weight percentages, CO-HTP-PUs (CO-HTP-50, CO-HTP-100, where HTP-FR was loaded as 50 and 100 wt%, respectively) were made and their flame-retardant and corrosion resistance properties were tested. The parent castor oil and MDI-based polyurethane (CO-PU) was concurrently synthesized and investigated as control for comparative appraisal. The FR behaviour of the PUs was examined using bomb-calorimetric testing and lab-scale flame tests. From the lab-scale flame test, it was found that the intumescent char length of the CO-HTP-100 after burning is longer than that of the CO-HTP-50 due to its high HTP-FR content. A substantial decrease in gross heat of 8.23, and 13.17 % was observed for the CO-HTP-50, and CO-HTP-100, respectively compared to the control CO-PU. The intumescent FR mechanism of CO-HTP-PUs was studied using Thermogravimetric Analysis coupled with Mass Spectroscopy (TGA-MS) analysis and Energy-dispersive X-ray spectroscopy (EDX) elemental analysis with mapping. The increase in P content of the post-burn sample in comparison to their unburn counterparts, and the expulsion of nitrogen gas from the triazole moiety from CO-HTP-PUs corroborated the intumescent FR mechanism. High char yields at 700 °C of CO-HTP-100 (20.3 wt%) and CO-HTP-50 (15.5 wt%) when compared to control CO-PU (3.6 wt%) also substantiated the FR behaviour of CO-HTP-PUs. The performance of these protective coatings against corrosion was investigated by the electrochemical methods. The significantly low corrosion current (I corr) values (2.60 × 10−9 A/cm2), high polarization resistance (42.7 × 104 Ω cm2), bulk resistance values (10.4 × 106 Ω cm2) and low corrosion rate (3.0 × 10−5 mm/year) of CO-HTP-100 demonstrate the excellent corrosion resistance property of HTP-FR. [Display omitted] • Design & synthesis of non-halogenated reactive flame retardant with anti-corrosive properties • The hydroxy functionalized FR is comprised of both triazole and phosphorus moieties. • FR Grafted on castor polyurethane showed intumescence & superior flame retardancy. • Demonstrate excellent corrosion resistance property of HTP-FR [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) acted as an inorganic filler has attracted great attention in the construction of polymer-based composite coating film. Nevertheless, the high surface area, obvious van der Waals forces, and abundant hydrophilic groups of GO result in its poor dispersion behavior and compatibility in hydrophobic polymer, which greatly limits its widespread practical application. To solve the above issue, we have prepared SiO 2 -decorated GO (GO-SiO 2) nanoparticles using the sol-gel hydrolysis method. The FTIR, Raman spectra, XPS and SEM analysis displayed that GO-SiO 2 nanoparticles were successfully constructed and the SiO 2 nanoparticles are covalently grafted onto GO sheet surfaces. Moreover, the GO-SiO 2 nanoparticles are further employed as inorganic fillers into the non-solvent UV-curable castor oil-based polyurethane acrylate (COPUA) systems for the preparation of composite coating films. Herein, the GO-SiO 2 nanoparticles can be uniformly dispersed in hydrophobic COPUA-based coating precursor, and have favorable compatibility with COPUA resin. The incorporation of GO-SiO 2 nanoparticles into the coating film matrix would slightly decrease the gel content of coating films (all gel contents are above 91.5 %) while improving the hydrophobic property of coating films. Furthermore, the thermal stability and mechanical performance of coating films have reasonably enhanced trends by the incorporation of GO-SiO 2 nanoparticles. The prepared coating films display favorable acid, alkali, and solvent resistance, and the high content of GO-SiO 2 nanoparticles is beneficial to aggrandize the anticorrosion performance of coating films. This work provides a universal approach to modify GO sheets and construct multifunctional modified GO/polyurethane composite film for coating application. [Display omitted] • SiO 2 -decorated GO sheets (GO-SiO 2) are prepared by the sol-gel hydrolysis method. • GO-SiO 2 has nice suspendability and compatibility in hydrophobic coating system. • GO-SiO 2 /castor oil-based polyurethane film is formed by non-solvent UV-curing way. • GO-SiO 2 avails to enhance thermal, mechanical and anticorrosive properties of film. • This work provides a facile method to prepare GO/polyurethane-based coating film. [ABSTRACT FROM AUTHOR]

There are numerous noxious bacteria, fungi and parasites in environment for human survival, so antibacterial materials are significant for medical devices, food packaging, and personal care. UV–curable silicone modified antibacterial materials were prepared from Schiff base–containing silicone modified hyperbranched thiol and castor oil based polyurethane acrylates (PUAs) by UV initiated thiol–ene click reaction. It exhibited that these UV–curable materials show fairly good antimicrobial activity of Escherichia coli (E. coli) and Neurospora crassa. A contact–kill antibacterial mechanism was proposed according to the antibacterial behavior of these UV–curable materials. These materials also exhibit a fairly high transparency over 92 % and pencil hardness can reach 4H. It need to be pointed out that the surface water contact angle of these materials is in the range of 84.1°–74.7°, which means these materials exhibit a certain degree of hydrophilicity, which can overcome the shortcoming of traditional polydimethylsiloxane(PDMS) to some content. These UV–curable materials show quite good mechanical performance because the tensile strength of them can reach 11.6 MPa. It denotes that the UV–curable Schiff base–containing antibacterial silicone modified materials may be a good candidate of antibacterial materials. [Display omitted] • UV–curable Schiff base–containing silicone modified materials exhibit fairly good antimicrobial activity follow a contact–kill antibacterial mechanism. • The materials show quite good mechanical performance with the tensile strength of 11.6 MPa. • The materials are with fairly high transparency over 92 %. • The materials have fairly high Pencil hardness of 4 H. [ABSTRACT FROM AUTHOR]

The paper describes coating properties (pencil hardness, adhesion, flexibility, solvent resistance) of a flexible biobased polyepoxide network from diglycidyl ether of bisphenol A crosslinked with castor oil maleate. Curing kinetics, electrical and photochemical behaviour were described. The structure was confirmed by Fourier transform infrared spectroscopy (FTIR). Global kinetic curing parameters values were determined via differential scanning calorimetry (DSC), by applying the Ozawa, Kissinger and non-linear regression methods. Kinetic parameters of each individual stage, obtained through multivariate non–linear regression method, indicated a three stage curing mechanism. A good correlation was found between experimental data and that simulated by the applied software. The material was further characterized by DSC and dielectric measurements. Crosslinking density and Shore hardness were determined from swelling and mechanical tests. 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol photostabilizer was added and photochemical behaviour was assessed at two different wavelengths. [ABSTRACT FROM AUTHOR]

The present study describes the synthesis of polyurethane and polyurethane/nanosilica (MBPU/NS) hybrid films and coatings based on castor oil, transesterified castor oil, palm oil based isocyanate and 1,4 butanediol. As a feasible alternative to the petrobased isocyanate a candid approach has been undertaken to synthesize polyurethane nanocomposite from palm oil based isocyanate. The results indicate that the polyurethanes derived from transesterified castor oil presents improved properties as compared with polyurethanes derived from castor oil owing to higher crosslinking density. Further, improvement in the properties of transesterified polyurethane was achieved through the incorporation of nanosilica. The formation of MBPU/NS composite was confirmed through Fourier transform infrared spectroscopy (FTIR). Atomic force microscopy (AFM) and transmission electron microscopy (TEM) studies indicated well dispersed nanosilica within the polyurethane matrix along with formation of phase segregated morphology and rough surface. The MBPU/NS composite exhibited higher thermal, swelling and coating properties owing to extensive crosslinking, phase segregation and H-bonding. Thus, the above synthesis method can be utilized for developing eco-friendly polyurethane nanocomposite coatings with high end application. [ABSTRACT FROM AUTHOR]

In this paper, UV-curable castor oil-based polyfunctional polyurethane acrylate (COME-PUA) was synthesized via photo-click chemistry and isocyanate polyurethane reaction. Facile and highly efficient side-chain functionalization of castor oil (CO) was first achieved via thiol-ene photo-click chemistry with β-mercaptoethanol (ME). 1 H NMR result indicated that almost 100% conversion of double-bond in CO was observed within 10 min, and the average hydroxyl functionality of the obtained polyol COME was about 6. Next, COME was modified by isocyanate polyurethane reaction with hydroxypropyl acrylate (HPA), isophorone diisocyanate (IPDI) and PEG-200 as the chain extender in order to prepare the resin COME-PUA. Results of both 1 H NMR and FTIR revealed that the targeted COME and COME-PUA were successfully synthesized. Furthermore, UV-curing kinetic of COME-PUA was revealed by real-time FTIR, showing a higher UV-curing rate than the common CO-PUA. Finally, some physical properties of curing films were studied. [ABSTRACT FROM AUTHOR]

Polymeric coating technology provides a cost-effective and convenient solution for the surface pollution and corrosion issues on various substrates. Herein, a series of transparent and omniphobic bio-based polyurethane (PU) coatings with high hardness, excellent anti-smudge and anti-corrosion properties were prepared by using castor oil as bio-polyol, hexamethylene diisocyanate trimer (HDIT) as a cross-linking agent, and a small amount of monocarbinol terminated polydimethylsiloxane (PDMS-OH) as an eco-friendly anti-fouling agent. Effects of the R-value (mole ratio of isocyanate groups to hydroxyl groups) and dosage of PDMS-OH (wt%) on the PU-PDMS coating's hardness, surface wettability, anti-smudge and anti-corrosion performance have been thoroughly investigated. It was found that the higher R-value led to increased coating hardness. The element content of silicon on the coating surface was confirmed to be higher than the theoretical value since the grafted PDMS chains partially enriched from the inner matrix to the coating surface for reducing overall surface energy. Various simulated water-based contaminants could quickly slide off from the coating surface without leaving any traces. Writing traces of oil-based marker could be shrunk immediately after writing and wiped clean from coating surface completely. Such anti-smudge properties could be maintained even after 1000 cycles of polishing. Moreover, the anti-corrosion performance of these PU-PDMS coatings has been investigated through electrochemical tests. The capacitance circular arc radius of PU 1.5 -PDMS 4.0 is 10 times of tinplate and 4 times of PU 1.5 , indicating the obtained coatings could offer better corrosion protection for tinplate than the regular PU coatings. This work would broaden the polyurethane application in omniphobic anticorrosion coatings. [Display omitted] • PU coating was prepared using castor oil as polyol directly without modification. • Pencil hardness enhanced greatly from 3H of previous anti-smudge PU coating to 7H. • Anti-smudge property induced by PDMS migration to form a thin layer on the surface of coating. • Transparent PU-PDMS coating has excellent anti-corrosive performance. [ABSTRACT FROM AUTHOR]

Waterborne castor oil-based polyurethane-silica hybrid materials with chemically bonded polymer matrix and silica nanoparticles were designed and prepared. The formation of cross-linking structures in the waterborne polyurethane system was confirmed by Fourier transform infrared spectroscopy. Transmission electron microscopy images indicated that nano-silica was encapsulated by polyurethane and exhibited an apparent core–shell structure. The nano-silica in the polyurethane matrix was vital in improving both the hydrophobicity and thermal stability of the resulting hybrid polyurethane films. With increased silicone content, the roughness, hydrophobicity, and thermal stability of the films were enhanced, but the transparency of the films in the 300–800 nm region was decreased. These results can aid in the design of bio-based hydrophobic waterborne polyurethane films with favorable thermal stability and optical transmittance. [ABSTRACT FROM AUTHOR]

The use of new materials from natural origin in the synthesis of urethane-derived polymers is recently drawing eminent care from social, environmental and also economic viewpoints. In this work, NCO-terminated castor oil-based polyurethane prepolymer (COPUP) is synthesized through the reaction between the isophorone diisocyanate (IPDI) and castor oil (CO) with a variable ratio of the isocyanate ( NCO) and hydroxyl ( OH) groups (0.5:1; 1:1; 1.5:1; 2:1) analyzed by nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy. Furthermore, the polyurethane prepolymers synthesized from IPDI played a significant role of inter-mixing between the soft polyether segments and the hard urethane groups, as shown by the analysis of hydrogen bonding in FT-IR deconvolution. A detailed study of the relationship between structure–property of cured prepolymers was carried out. As a result, COPUP obtained from biomass-derived polyols may enhance a promising alternative to the use of other petrochemicals in the paving industry. [ABSTRACT FROM AUTHOR]

Glycolysis of poly(ethylene terephthalate) (PET) waste using different molar ratio of poly(ethylene glycol) (PEG400), was used to produce saturated hydroxyl-functional polyester polyols with castor oil (CO) by transesterification process. The waterborne polyurethane (WBPU) adhesives were synthesized from these saturated polyester polyols, isophorone diisocyanate (IPDI), dimethylolpropionic acid (DMPA), and hexamethoxymethyl melamine (HMMM) as cross-linking agent by a conventional prepolymer process. The glycolyzed polyols and polyester polyos formations were characterized using Fourier transform infrared spectroscopy (FTIR) and the molecular weights were determined using gel permeation chromatography (GPC). The cross-linking reaction between WBPU and HMMM was verified using FTIR and 1 H NMR analysis. Thermal properties were investigated by thermogravimetric analysis (TG). Thermal stability of cross-linked WBPU significantly increased with decreasing castor oil content in the process of transesterification to obtain polyester polyol as a soft segment. The T 15% and T 50% (the temperature where 15 and 50% weight loss occurred) of WBPU increased with the decreasing of castor oil content in the obtained polyester polyols, caused by the steric hindrance of polyester polyol with higher castor oil content, in the process of cross-linking reactions with HMMM. The physico-mechanical properties of WBPU, such as hardness, adhesion test, and gloss of the dried films were also determined considering the effect of participation of HMMM in cross-linking reactions with polyurethane, on coating properties. [ABSTRACT FROM AUTHOR]

In this paper, the sapium sebiferum oil-based polyols (SOP) were prepared by thiol-ene photo-click reaction with mercaptoethanol and inedible sapium sebiferum oil with high iodine value. The molecular structure and hydroxyl values of the SOPs were determined. Then, modified castor oil based waterborne polyurethane was prepared by using SOP, castor oil and isocyanate as raw materials. The particle size and the chemical structure of the emulsions were characterized. Anti-graffiti properties, water contact angle, mechanical properties and thermal properties of the films were tested. When the mass ratio of the SOP to castor oil increased, the water contact angle of the modified film increased by nearly 20°, and it showed good anti-graffiti performance, which can be erased by dry bumf without leaving trace after being written by marker. In addition, the temperature of 50% weight loss of modified film increased by 12 °C and the tensile strength and elongation at break can be improved 2.2 and 2.8 times than before, respectively, which may be related to the addition of crosslinking in the polyurethane by polyhydroxy SOP. [Display omitted] • A novel bio-based crosslinking agent SOP can improve the performance of CWPU. • The two kinds of vegetable oils and emulsifier used in the preparation of CWPU-SOP are environmentally friendly and renewable. • By thiol-ene photo-click reaction, the SOP was prepared by inedible SO which with high iodine value. [ABSTRACT FROM AUTHOR]

To obtain eco-friendly high solid and excellent anti-corrosive polyaspartic (PAS) coating, a novel self-thixotropic nanofiller, hydrogenated castor oil modifying graphene oxide (HMGO) nanosheet, was fabricated and blended into the PAS coating to enhance its corrosion resistance. The self-thixotropic HMGO nanosheets were synthesized from 3-aminopropyltriethoxysilane (APTES) modified graphene oxide sheets by grafting the hydrogenated castor oil (HCO) with long alkyl chain molecular structure. HMGO could form a three-dimensional hydrogen network, separating and stabilizing the nanosheets in the polyaspartic coating matrix homogeneously, so that the HMGO/polyaspartic nanocomposite coating did not contain free low molecules or free inorganic nanofillers. Electrochemical impedance spectroscopy (EIS) and salt spray testing of HMGO/polyaspartic nanocomposite coatings with 86 wt% high solids have shown that corrosion protection properties have been significantly improved with the addition of self-thixotropic HMGO nanofiller. Compared with other nanofillers, including graphene oxide and APTES modified graphene oxide, HMGO nanosheets presented an impressive improvement in corrosion resistance of polyaspartic coatings. The superiority of HMGO/polyaspartic nanocomposite coating is owing to the self-thixotropic effect of HMGO promoted homogeneous distribution and high compatibility of HMGO nanosheets in polyaspartic polymer matrix. • Preparation of high-solid anticorrosive coating with self-thixotropic HMGO and polyaspartic resin • The HMGO nanofillers are fabricated by modified graphene oxide grafting hydrogen castor oil. • HMGO nanofillers exhibit excellent rheology, dispersion and hydrophobic properties. • Robust and long-term anticorrosion property of coating are achieved. [ABSTRACT FROM AUTHOR]