Preparation and characterization of UV-cured polyurethane acrylate/ZnO nanocomposite films based on surface modified ZnO

A series of polyurethane acrylate (PUA)/ZnO nanocomposite films with different ZnO contents were prepared via a UV-curing system. To ensure good dispersion in the PUA matrix, ZnO nanoparticles were modified with a silane coupling agent and confirmed by FT-IR analysis. The morphological structures, thermal properties, mechanical properties and water transfer properties of the prepared films were investigated as a function of their ZnO concentration. WAXD and SEM analyses showed that the surface-modified ZnO nanoparticles were homogeneously dispersed in the PUA matrix and the molecular ordering increased with increasing ZnO content. Compared with neat PUA, the hardness and elastic modulus in films increased from 0.03 to 0.056 GPa and from 2.75 to 3.55 GPa, respectively. Additionally, the water uptake and WVTR in the PUA/ZnO nanocomposite films decreased as the ZnO content nanoparticles increased, which may come from enhanced molecular ordering and hydrophobicity in films. UV light below approximately 450 nm can be efficiently absorbed by incorporating ZnO nanoparticles into a PUA matrix, indicating that these composite films exhibit good weather ability and UV-shielding effects. The enhanced physical properties achieved by incorporating modified ZnO nanoparticles can be advantageous in various applications, whereas the thermal stability of the composite films should be increased.     

Aqueous PUA emulsion prepared by dispersing polyurethane prepolymer in polyacrylate emulsion

Waterborne polyurethane/polyacrylate (PUA) emulsions were prepared by dispersing polyurethane (PU) prepolymer in polyacrylate (PA) emulsion; therefore, the PU particles formed in the presence of PA nanoparticles. The particle size and its distribution of the composite PUA emulsion were determined by dynamic light scattering. The result shows that the average particle size increases initially and then decreases with increasing PA content, which is confirmed by transmission electron microscope characterization. The surface properties of PUA films were analyzed by water contact angle and atomic force microscope topography. It indicates that the water contact angle and the average roughness of the composite PUA films are larger than those of the PU film. Meanwhile, mechanical properties test, scanning electron microscopy, and thermogravimetric analyses disclose that the PUA films are characterized by enhanced tensile strength, rough fractured surface, and good thermal stability. The preparation method proposed in this article is an effective and convenient way to manufacture composite PUA emulsion. The composite PUA emulsion can be potentially used in coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43203.     

Preparation and properties of poly(urethane acrylate) (PUA) and tetrapod ZnO whisker (TZnO‐W) composite films

Tetrapod zinc oxide whiskers (TZnO‐Ws) were successfully synthesized via a thermal oxidation method and confirmed using Fourier transform infrared spectroscopy, X‐ray diffraction and scanning electron microscopy. A series of poly(urethane acrylate) (PUA)/TZnO‐W composite films with various TZnO‐W contents were prepared via a UV curing method and their physical properties were investigated to understand their possible use as packaging materials. The morphological, thermal, mechanical, antibacterial and barrier properties of the PUA/TZnO‐W composite films were interpreted as a function of TZnO‐W content. The thermal stability, barrier properties and antibacterial properties of the composite films, which were strongly dependent upon their chemical and morphological structure, were enhanced as the TZnO‐W content increased. The oxygen transmission rate and water vapor transmission rate decreased from 614 to 161 cm³ m^?2 per day and 28.70 to 28.16 g m^?2 per day, respectively. However, the mechanical strength of the films decreased due to the low interfacial interaction and poor dispersion with high TZnO‐W loading. The enhanced barrier properties and good antibacterial properties of the PUA/TZnO‐W composite films indicate that these materials are potentially suitable for many packaging applications. However, further studies are needed to increase the compatibility of polymer matrix and filler. © 2012 Society of Chemical Industry     

Preparation and properties of hydrophobic layered silicate-reinforced UV-curable poly(urethane acrylate) nanocomposite films for packaging applications

A series of poly(urethane acrylate)/Cloisite 15A (PUA/C15A) nanocomposite films were successfully prepared via a UV-curing system, and their physical and barrier properties were investigated as a function of clay content. The physical properties were strongly dependent upon the chemical and morphological structures originating from differences in Cloisite 15A content. With high clay content, the PUA/C15A nanocomposite films displayed an intercalation/exfoliation combined structure. However, no strong interfacial interactions occurred between the PUA and clay, possibly leading to poor dispersion with relatively high clay content. The thermal stability displayed some enhancement with the introduction of clay into PUA, while the gas and moisture barrier properties showed significant enhancement. The oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) decreased with increasing contents of Cloisite 15A, and varied within the range of 714.0–71.1 cm³/m² day and 29.9–13.9 g/m² day, respectively. Thus the enhanced gas and moisture barrier properties of PUA/C15A nanocomposite films make them promising candidates for food and pharmaceutical packaging applications. However, further studies will be performed to increase the compatibility and dispersion of clay particles in the PUA polymer matrix.     

丙烯酸酯改性非离子型水性聚氨酯的合成及性能

以异佛尔酮二异氰酸酯(IPDI)、聚氧化丙烯二醇(N-210)、聚氧化乙烯二醇(PEG)等为基本原料,丙烯酸羟乙酯(HEA)为封端剂,合成了非离子型双键封端水性聚氨酯(HPU)自乳化乳液,然后与甲基丙烯酸甲酯(MMA)及丙烯酸丁酯(BA)进行自由基聚合,得到丙烯酸酯改性非离子型水性聚氨酯(PUA)乳液.对这种材料进行了耐水性、粒径及热力学等方面的测试,结果表明:PUA乳液粒子有明显核壳结构,乳液的平均粒径增大;胶膜耐水性随着HPU添加量的提高而降低,胶膜的耐热性有明显提高.     

聚氨酯-丙烯酸酯复合乳液的结构与性能研究进展

综述了聚氨酯一丙烯酸酯(PUA)复合乳液的结构与性能的研究进展,包括乳液的稳定性、流变性．胶粒的粒径、结构形态、胶膜的表面结构、热学性能、力学性能和耐化学品性能等;讨论了PUA复合乳液结构与性能的影响因素,指出PUA复合乳液的优异性能在很大程度上取决于胶粒的核壳结构,深入研究结构与配方、合成工艺,结构与性能之间的相互关系将会大力促进PUA复合乳液的发展。     

聚氨酯丙烯酸酯浸渍固化对淀粉-纤维素复合膜性能的影响

利用聚氨酯丙烯酸酯树脂（PUA）对淀粉-纤维素膜进行改性,以改善材料性能。先以玉米淀粉和纤维素为主要原料,在无机盐氯化锌水溶液中溶解,用流延法制备淀粉-纤维素混合膜（RSC）;再以PUA为浸渍树脂,采用浸渍固化法制备淀粉-纤维素-聚氨酯丙烯酸酯复合膜（RSC-PUA）,考察树脂浓度、光固化时间等因素对复合膜力学性能、吸水性能的影响,并通过扫描电镜、X射线衍射仪、热重分析等手段表征复合膜形貌和结构。实验结果表明：最适宜树脂质量分数为30%,光固化时间为120s;RSC-PUA复合膜比RSC膜拉伸强度提高2.4倍,断裂伸长率提高6倍,吸水率降低了53.6%,热裂解温度增高113℃。以上结果表明,经PUA树脂改性后的复合膜的力学性能、耐湿性、热稳定性提高。     

聚含氟丙烯酸酯/聚氨酯共聚物细乳液的制备及表征

以甲苯二异氰酸酯(TDI)和甲基丙烯酸羟乙酯(HEMA)为原料,合成了丙烯酸酯/聚氨酯(PUA)预聚体;采用细乳液聚合法,合成了聚含氟PUA细乳液。使用红外光谱(FT-IR)和核磁共振(1H-NMR)表征了PUA预聚体及共聚物的结构组成,用激光光散射粒度仪(PCS)分析了乳胶粒的粒径及其分布,并考察了氟单体用量对乳胶膜的吸水率和表面性能的影响。研究结果表明,乳胶粒的粒径随着PUA预聚体用量的增加而增大;当氟单体质量分数由0增至20%时,乳胶膜的吸水率由10.3%降至4.2%,表面自由能由34.89mJ/m2降至15.66mJ/m2,说明氟单体的加入较好地改善了乳胶膜的表面性能。     

二羟甲基丙酸用量对聚氨酯-丙烯酸酯离聚物乳液性能的影响

用甲苯二异氰酸酯、聚己二酸新戊二醇酯多元醇(PDGA)、二羟甲基丙酸(DMPA)和甲基丙烯酸-2-羟乙酯合成了聚氨酯-丙烯酸酯(PUA)离聚物乳液,讨论了DMPA用量对其性能的影响。结果表明,当DMPA与PDGA的摩尔比增大时,PUA离聚物乳液的平均粒径减小,粒径分布变窄,黏度增大,稳定性提高,但DMPA用量过高时,会使具有高表面能的小粒子团聚,从而给PUA离聚物的乳液性能带来负面影响。     

Kinetics analysis and physical properties of photocured silicate-based thiol-ene nanocomposites: The effects of vinyl POSS ene on the polymerization kinetics and physical properties of thiol-triallyl ether networks

The kinetics and thermal/physical properties of the trithiol-TAE (triallyl ether) system were measured with respect to increasing polyoligomeric silsesquioxane (POSS) concentrations in order to understand how the presence of POSS nanoparticles affects network formation at low loadings. Vinyl POSS monomer (vPOSS-Bu₄) with both vinyl and carboxylate pendant groups was synthesized via a thermally initiated, free-radical reaction to improve the compatibility of the inorganic particles with the trithiol and triallyl ether comomoners. Chemically modified vPOSS-Bu₄ particles were incorporated into the trithiol-TAE polymer networks by a thiol-ene free-radical photopolymerization at molar concentrations of 0, 1, and 5 ene mol%. The polymerization rates were analyzed using real-time FTIR and photo-DSC. The polymerization rates showed no significant changes with increasing vPOSS-Bu₄ concentration. Thermal analyses of the films by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) demonstrated that thermal stability improves without affecting T _g as the POSS concentration increased. Additionally, scratch resistance increased and flame spread decreased markedly with increasing POSS concentration for concentrations up to 5 mol% vPOSS-Bu₄.     

Effects of reactive and nonreactive POSS types on the mechanical,thermal, and morphological properties of plasticized poly(lactic acid)

The aim of this study is to investigate the effects of the reactive and nonreactive polyhedral oligomeric silsesquioxane (POSSs) types and their composition on the mechanical, thermal, and morphological properties of poly(ethylene glycol) plasticized poly(lactic acid) (PLA) composites prepared with melt compounding. The results showed that the incorporation of POSS decreased the melt viscosity of the compounds regardless of POSS type. The lowest viscosity was obtained with epoxy‐POSS, which is the only one that is liquid at processing temperature in comparison to the others. It was revealed from the mechanical tests that the toughness‐related properties such as impact strength and elongation at break improved by the addition of POSS without remarkable deterioration in stiffness. The chemical structure of the POSS influenced the level of dispersion and hence the mechanical performance of the composites. Octaisobutyl‐POSS, being the nonreactive and nonpolar one, had the best dispersion among the other reactive and polar POSS types. The glass transition temperature of the matrix decreased in the presence of POSS types. In addition, the POSS particles also had an impact on the crystallization of PLA. The thermal stability of the composites improved in the presence of POSS particles with respect to the POSS content and the POSS type. POLYM. ENG. SCI., 54:264–275, 2014. © 2013 Society of Plastics Engineers     

Characterization of waterborne polyurethane for ecofriendly functional floor plate

Three types of nonmetallic mineral particles (CaCO₃, TiO₂ and loess) were incorporated into waterborne polyurethane acrylate (PUA) to improve the surface properties of ecofriendly floor tiles. Several properties of PUA containing nonmetallic mineral materials were measured by Fourier transform infrared spectroscopy (FT-IR), a dynamic mechanical thermal analyzer (DMTA), swelling tests, and contact angle measurement. Upon decreasing the molecular weight between crosslinks (variation of molecular weight of the polyol), the modulus and glass transition temperature (T_g) of the PUA film increased because of the increase in crosslinking density. Resistance properties such as swelling and contact angle against water were enhanced with the addition of nonmetallic mineral particles because of the increase in the hydrophobic nature of the polymer matrix.     

In-situ polyurethane/polyacrylate microemulsion formation: the effects of acrylic content in wood coating application

In-situ surfactant-free emulsion polymerization was utilized to prepare polyacrylate/polyurethane (PUA) microemulsions in the absence of surfactant and organic solvent. For this purpose, PUA with higher acrylate content was successfully prepared, with the aim to reduce the coating cost. The dynamic light scattering results showed that the particle size of PUA microemulsion displayed a unimodal distribution and the particle size was ranged from 33 to 61 nm. In comparison with PUA prepared with conventional miniemulsion polymerization, the particle size distribution coefficient dropped by one order. Atomic force microscopy, together with thermogravimetric analyzer, demonstrated good compatibility and interaction between PU and acrylic components, and no phase separation was detected even at 58 wt% acrylic content. With the incorporation of acrylic component, the thermal stability and maximum stress were improved. The maximum stress greatly increased from 4.6 to 30.9 MPa, and the maximum stress of in-situ PUA was nearly three times larger than that of PUA prepared by miniemulsion polymerization. The effects of acrylic content on water resistance, pencil hardness, adhesion, and impact strength of wood coating were evaluated. With increasing the acrylic content, the water resistance and pencil hardness increased, though the impact strength of in-situ PUA films was slightly reduced.     

Synthesis and characterization of UV-curable waterborne polyurethane–acrylate ionomers for coatings

A new kind of ultraviolet (UV)-curable waterborne polyurethane–acrylate (PUA) ionomer, prepared from toluene diisocyanate (TDI), polyethylene glycol (PEG), dimethylolpropionic acid (DMPA), triethylamine (TEA), and 2-hydroxyethyl methacrylate (HEMA), was synthesized by the modified prepolymer mixing process in which water serves as a chain-extender and dispersant. Fourier transform infrared (FTIR) spectra demonstrated the formation of the PUA ionomers both in dispersions and in their corresponding cured films. Surface tension of the PUA dispersions decreased as the DMPA-to-PEG mole ratio increased. The investigation of rheological behavior of the PUA dispersions suggested that all the dispersions belong to pseudoplastic fluid and display the characteristic of common polymer dispersions. Differential scanning calorimetry (DSC) analysis showed that the increasing DMPA-to-PEG mole ratio may result in a higher T_g and a broader transition zone for the hard segment. The results of TGA for the PUA-cured films indicated good thermal stability with no appreciable weight loss until well above 200°C. Measurement of physical properties showed that all the PUA-cured films exhibited excellent adhesion, gloss, flexibility, and impact strength, as well as pendulum hardness, depending upon hard segment content. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2869–2876, 1999     

聚脲/丙烯酸酯乳液的合成及性能研究

以异佛尔酮二异氰酸酯(IPDI)、聚醚胺D-2000、二羟甲基丙酸(DMPA)、丙烯酸羟乙酯(HEA)为原料,合成双键封端的聚脲预聚体,再通过种子乳液聚合法,与丙烯酸酯单体聚合,制备聚脲/丙烯酸酯(PUAA)乳液。研究了R值、DMPA用量以及聚脲(PUA)与聚丙烯酸酯(PA)质量比对合成乳液稳定性、耐水性、力学性能等的影响。红外光谱分析表明聚脲与丙烯酸酯成功接枝。实验结果表明:R值为1.6时,乳胶膜吸水率最低;而随R值增大,乳胶膜的拉伸强度增大,断裂伸长率减少。实验优选DMPA的用量占PUA预聚体的5.0%,PUA与PA质量比为2∶3~1∶2,制得的PUAA乳液稳定,吸水率低,力学性能好。     

Novel elastomer‐dumbbell functionalized POSS composites: Thermomechanical and Morphological Properties

Nanocomposites consisting of poly(styrene‐b‐butadiene‐b‐styrene) (SBS) and polyhedral oligomeric silsesquioxanes (POSS) were prepared using a solvent dispersion method. Dumbbell‐shaped POSS fillers were prepared using diacyl chlorides to bridge the POSS molecules. Infrared spectroscopy confirmed functionalization. Scanning electron microscopy revealed an increase in filler aggregation with concentration, with preferential phase selectivity. Polydispersity increased with filler concentration while d spacing was influenced by phase selectivity and domain‐filler compatibility. Functionalized POSS improved thermal stability by imparting restrictions of SBS chain motions. Tensile stress–strain analysis revealed an increase in modulus, yield strength, and strain hardening with filler concentration, while creep deformation decreased and permanent strain increased with POSS content. Storage modulus, loss modulus, and glass transition temperature increased with filler content due to effective SBS–POSS interaction. Nanocomposite properties were influenced by filler concentration, the phase of the filler was dispersed throughout and the length of the alkyl “barbell” on the dumbbell‐shaped POSS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

四配位硅/丙烯酸醋改性水性聚氨醋的制备及性能

采用四配位硅单体对丙烯酸酯、聚氨酯杂合水分散体进行改性,制备出具有核壳结构的共聚乳液(Si-PUA).研究了MMA添加量对Si-PUA乳液及涂膜性能的影响.并利用红外光谱(IR)、热失重(TG)、差示扫描量热(DSC)分析等手段分别进行了表征.研究表明:随着MMA含量的增加,体系聚合稳定性变差,MMA的适合添加量为Si-PUA总质量的20%～30% ; PUA涂膜的耐水性和耐溶剂性明显优于PU涂膜,而用四配位硅单体改性后的Si-PUA涂膜,改性效果更加显著.IR表明,MMA、四配位硅单体是参加了聚合反应;DSC表明通过MMA和四配位硅的改性,使得PU的软段和硬段的相容性增加.TG表明改性后的水性聚氨酯耐高温性能有所提高.     

Thermal,optical, and water sorption properties in composite films of poly(ether imide) and bismaleimides: Effect of chemical structure

Two series of semi‐interpenetrating polymer network (semi‐IPN) composite films, PEI/bismaleimide (UTBM) and PEI/fluorinated BMI (UTFBM) were prepared using a thermoplastic PEI and two different crosslinkable imide moieties. The effects of chemical structure and content of crosslinkable imide moieties on thermal stability, dielectric properties, and water sorption have been investigated. Glass transition temperature and weight loss temperatures increased with increase in the content of crosslinkable imide moieties, indicating the enhanced thermal stability of the semi‐IPN composite films. The refractive indices of the semi‐IPN composite systems increased with increasing crosslinkable imide moieties due to the higher polarizabilities of atoms. The water sorption of the semi‐IPN composite films was significantly decreased by the incorporation of crosslinkable imide moieties, which are interpreted by morphological structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

聚氨酯-丙烯酸酯复合乳液研究进展

论述了聚氨酯一丙烯酸酯（PUA）复合乳液研究进展,包括制备方法、乳液粒径大小及分布、粘度、乳胶粒形态结构,胶膜的表面结构、形态结构、热性能、热稳定性和物理机械性能等。探讨了影响PUA复合乳液结构与性能的主要因素。最后指出,深入研究PUA胶膜微观结构,制备纳米级、高固含量PUA复合乳液是今后发展方向。     

Preparation,properties, and applications of acrylic–polyurethane hybrid emulsions in extinction electrophoresis

Aqueous acrylic–polyurethane hybrid emulsions (PUA) were fabricated by semibatch emulsion copolymerization using a mixture of acrylic (AC) monomers in the presence of an isocyanate terminated polyurethane (PU). The effects of PU content on the morphology of the hybrid emulsions and film properties were here investigated in detail using FT‐IR, UV, TEM, and SEM. TEM images clearly showed that hybrid emulsions exhibited a core‐shell structure before neutralization. However, after neutralization with N,N‐dimethylethanolamine, the typical particles exhibited phase inversion, producing particles with irregular hemispheres shapes and diameters about 0.5 μm. SEM images showed that the film surface became rougher as PU content increased, peaking at 10 wt %, the gloss of this film was 23.1 (60°). The UV transmittance spectra of the PUA hybrid emulsion within a wavelength range 700–200 nm decreased as PU content increased. This was consistent with the changes in the surface roughness of the film. Electrophoresis took place on an aluminum alloy surface and the product was dried at 120°C. The film exhibited excellent mechanical performance due to curing reaction between the N?C?O group on PU and hydroxyl group on the AC copolymer. The gloss of the film was found to be as low as 4.0 after electrophoresis testing. These films may be useful in practical extinction electrophoresis. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40078.