PS/PU硬核软壳核壳聚合物增韧改性聚苯乙烯

采用丙酮法合成了水性聚氨酯(PU),以核壳种子乳液聚合法合成了核壳质量比为1:1的聚苯乙烯(PS)/PU硬核软壳核壳聚合物。对核壳聚合物进行傅里叶变换红外光谱测试、动态热机械分析,并以核壳聚合物质量分数为变量设计了一系列质量分数梯度,对PS进行了增韧改性研究。结果表明:预期设计的核壳结构粒子形成;加入相容剂后形成了部分相容体系,PS/PU核壳结构增韧改性剂质量分数在20%以上时,共混体系熔体在受应力状态时更多表现为弹性形变,且随核壳结构增韧改性剂质量分数增加而上升。PS/PU核壳结构增韧改性剂质量分数为20%时,共混体系的冲击强度为纯PS的261.23%,达到最佳。     

聚氨酯/碳纳米管复合材料的制备与表征

采用预聚体法制备了聚氨酯/碳纳米管(PU/CNTs)复合材料,考察了该复合材料中CNTs含量对复合材料电性能、力学性能和热性能的影响及复合材料的微观结构。结果表明,碳纳米管在聚氨酯体系中能够较好地分散;扩链/交联剂对PU/CNTs复合材料的导电性能影响较大,TMP比MOCA交联的PU/CNTs复合材料导电性能好;用TMP作交联剂制备的PU/CNTs复合材料的力学性能明显低于以MOCA为扩链剂的PU/CNTs复合材料的力学性能;随着CNTs的加入,PU/CNTs复合材料储能模量和耗能模量明显增加,复合材料的阻尼性能大幅度提高。     

低密度PU发泡板在汽车内饰顶棚中应用及研究

介绍了汽车顶棚的结构组成和基本性能要求,并研制出一种全新的22kg/m3的低密度PU板。通过实验比较结构不同的汽车顶棚间在性能方面的差异,低密度PU发泡板的吸音降噪、储存时间、刚性强度等性能较原先聚氨酯(PU)材料有明显提升。     

V／PU共聚乳液用于纸张上光适应性研究

采用无皂乳液聚合技术合成了乙烯基-聚氨酯(V/PU)共聚乳液,要求该乳液微粒具有多层结构以适应纸张上光。初步研究了V/PU的比值对乳液涂层性能的影响,并以V/PU共聚乳液为成膜助剂配制出性能优异的水性上光涂料。     

氧化石墨烯增强聚氨酯阻燃及力学性能的研究

为提高聚氨酯(PU)材料的阻燃及力学性能,采用熔融共混的方法制备了含磷阻燃剂的氧化石墨烯/聚氨酯(GO/PU)复合材料。分析了GO/PU复合材料的微观结构及燃烧后碳层的形貌,研究了GO的用量对GO/PU复合材料阻燃性能及其老化前后力学性能的影响。结果表明:随着GO用量的增加,GO/PU复合材料的阻燃性能逐渐增加,加入5%的GO时,LOI值达到39.8%,垂直燃烧等级为V-0级;加入含磷阻燃剂后,GO/PU复合材料力学性能有所下降;添加GO后,对GO/PU复合材料的力学性能起到增强的作用,复合材料的耐老化性能也随着GO含量的增加而提高。     

相转化法制备聚氨酯/高纯铜粉微孔膜及性能研究

在聚氨酯(PU)中添加高纯铜粉(Cu),以N,N'-二甲基甲酰胺(DMF)为溶剂,采用相转化法制备了聚氨酯/高纯铜粉(PU/Cu)微孔膜。通过膜动力学测试仪、扫描电子显微镜(SEM)、热重分析仪(TGA)、毛细流孔径仪及电子万能试验机对PU/Cu微孔膜的结构和各项性能进行了研究。结果表明:加入Cu后,PU膜的热稳定性、成膜速率、力学性能、亲水性、透气性均有一定程度的改善,膜孔结构得到细化,孔隙率和吸湿率呈先减小后增大的趋势。综合各项性能,当Cu添加量为1.0%时,PU/Cu微孔膜的整体性能最好。     

废聚氨酯改性热塑性弹性体SBS的性能研究

以废聚氨酯(PU)改性热塑性弹性体苯乙烯-丁二烯-苯乙烯共聚物(SBS),探讨了废PU用量、相容剂对废PU/SBS复合材料的物理机械性能的影响以及废PU对含填料轻质碳酸钙(CaCO3)的SBS性能的影响;并采用相差显微镜观察了复合材料的亚微观结构.结果表明,废PU质量在15份左右时,废PU/SBS复合材料的综合性能最佳;相容剂虽然能够改善复合材料的界面,但是对宏观力学性能影响不大;废PU能够很好地改善CaCO3 /SBS的界面性质,同时大幅度提高了物理机械性能,用废PU改性的CaCO3/SBS材料具有较高的性价比.     

废聚氨酯改性热塑性弹性体SBS性能的研究

研究了废聚氨酯(PU)改性热塑性弹性体苯乙烯-丁二烯-苯乙烯(SBS)共聚物的性能;探讨了废PU用量、相容剂和轻质碳酸钙(CaCO3)对废PU/SBS复合材料物理机械性能的影响;用相差显微镜观察了复合材料的亚微观结构.结果表明,废PU用量为15份时,废PU/SBS复合材料综合性能最佳;相容剂虽然能够改善复合材料的界面状态,但对力学性能影响不大;废PU能够很好地改善CaCO3 /SBS的界面性质,同时大幅度地提高了物理机械性能,是一种具有高性能价格比的热塑性弹性体材料.     

聚氨酯/氮化硼包覆改性玻璃纤维透湿导热膜的制备与性能研究

以聚氨酯(PU)为基体、N,N'-二甲基甲酰胺(DMF)为溶剂,同时添加氮化硼包覆改性的玻璃纤维(GF-BN),采用相转化法制备了聚氨酯(PU)透湿导热膜。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、膜性能测试仪、热重分析仪(TGA)及电子万能试验机对PU膜的结构和性能进行了表征。结果表明:添加GF-BN后,PU膜的孔结构得到细化,大孔结构明显减少,连通性增强,薄膜的热交换效率、水通量、热稳定性、力学性能均有所改善。其中当GF-BN的添加量为0.6%时,PU/GF-BN共混膜的综合性能最好。     

泡沫行业CFC-11整体淘汰计划

《中国PU泡沫行业CFC-11整体淘汰计划》(简称《泡沫行业计划》)在2001年12月3日召开的《议定书》多边基金执委会第35次会议上获得批准,共获赠款5384.6万美元。 泡沫行业包括四个子行业,PU软泡,PU硬泡、自结皮、PS/PE,本次批准的《泡沫行业计划》涵盖了所有PU     

Characterization of castor oil–based interpenetrating polymer networks of PU/PS

A series of interpenetrating polymer networks (IPNs) of polyurethane/polystyrene (PU/PS; 90/10, 75/25, 60/40, and 50/50) have been synthesized by condensation reaction of castor oil with methylene diisocyanate and styrene, employing benzoyl peroxide as initiator. Polystyrene is extracted from IPNs by the Soxhlet extraction method. The IPNs of PU/PS before and after PS extraction were characterized for physical, optical, and X-ray diffraction properties. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1739–1743, 1998     

Synthesis and characterization of interpenetrating polymer networks from polyurethane and poly(ethylene glycol) diacrylate

Interpenetrating polymer networks (IPNs) combining polyurethane (PU) and poly(ethylene glycol) diacrylate (PEGDA) networks were prepared with simultaneous polymerization. PU was synthesized from biocompatible and biodegradable poly(ε-caprolactone) diol, and the hydroxyl group of poly(ethylene glycol) was substituted with a crosslinkable acrylate group. The effects of the PU/PEGDA compositions and the crosslink density of PU and PEGDA on the thermal properties, swelling ratio, surface energy, mechanical properties, and morphologies were investigated. The mechanical properties of PEGDA networks were improved by the presence of PU networks, particularly in the 75% PU/25% PEGDA IPNs. All PU/PEGDA IPNs showed a microphase-separated structure with cocontinuous morphology, as observed by atomic force microscopy, which was in agreement with the results of swelling ratio and dynamic mechanical thermal analysis measurements. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mechanical properties of blocked polyurethane/epoxy interpenetrating polymer networks

The mechanical properties of blocked polyurethane(PU)/epoxy interpenetrating polymer networks (IPNs) were studied by means of their static and damping properties. The studies of static mechanical properties of IPNs are based on tensile properties, flexural properties, hardness, and impact method. Results show that the tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs decreased with increase in blocked PU content. The impact strength of IPNs increased with increase in blocked PU content. It shows that the tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (CaCO₃) content to a maximum value at 5, 10, 20, and 25 phr, respectively, and then decreased. The higher the filler content, the greater the hardness of IPNs and the lower the notched Izod impact strength of IPNs. The glass transition temperatures (T_g) of IPNs were shifted inwardly compared with those of blocked PU and epoxy, which indicated that the blocked PU/epoxy IPNs showed excellent compatibility. Meanwhile, the T_g was shifted to a higher temperature with increasing filler (CaCO₃) content. The dynamic storage modulus (E′) of IPNs increased with increase in epoxy and filler content. The higher the blocked PU content, the greater the swelling ratio of IPNs and the lower the density of IPNs. The higher the filler (CaCO₃) content, the greater the density of IPNs, and the lower the swelling ratio of IPNs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1826–1832, 2006     

Effect of charge groups in polyurethane and polystyrene interpenetrating polymer networks

Opposite charges, namely tertiary amine and carboxyl groups, were introduced into polyurethane (PU) and polystyrene (PS), respectively, to prepare PU/PS interpenetrating polymer networks (IPNs) by means of simultaneous bulk polymerization. Four IPNs were synthesized: a full-IPN, two semi-IPNs and a linear blend. The effect of charge groups on the mechanical properties and morphology of the four polymer alloys was investigated. It is found that the PU/PS IPN which was incorporated with charge groups is free of any phase-separation, and sufficiently uniformly distributed, as can be seen from the corresponding scanning electron microscopy (SEM) photographs. Dynamic mechanical analysis indicates that the transition peak of the loss modulus E″ will move towards the centre between the two transition peaks of both components in the absence of charge groups, as a function of an increase in the contents of the opposite charge groups. Meanwhile the storage modulus E′ will decrease in a single-stage way from the previous two-stage mode. The tensile strength in all the four polymer alloys increased markedly along with an increase in the contents of acrylic acid (AA) in the poly(styrene-acrylic acid) (PSAA), which clearly can be seen for the PU/PSAA full-IPN.     

Interpenetrating polymer networks from castor oil-based polyurethanes and polystyrene,XXV

Interpenetrating polymer networks (IPNs) of castor oil-based polyurethanes and polystyrene were prepared by simultaneous polymerization. The liquid prepolyurethanes were formed by reacting the hydroxyl functionality of castor oil with isophorone diisocyanate using different stoichiometric NCO/OH ratios. These prepolyurethanes were mixed with styrene monomer and subsequently polymerized by free radical polymerization initiated by benzoyl peroxide in the presence of the crosslinker 1,4-divinyl benzene. The interpenetrating polymer networks. PU/PS IPNs, were obtained as tough and transparent films by the transfer moulding technique. These IPNs were characterized by the static mechanical properties (tensile strength, Young's modulus and % elongation), thermal properties and morphology. The dielectric relaxation properties (σ, E′, E″ and tanδ) of the IPNs at different temperatures were studied.     

Synthesis and characterization of polyurethane/epoxy interpenetrating network nanocomposites with organoclays

Summary Novel nanocomposites with varying contents of organophilic montmorillonite (oMMT) were prepared by intercalating oMMT to interpenetrating polymer networks (IPNs) of polyurethane and epoxy resin (PU/EP). The PU/EP networks and the oMMT modified PU/EP IPNs nanocomposites were studied with Fourier transform infrared spectrometry, scanning electronic microscopy, transmission electronic microscopy, wide-angle X-ray diffraction, water absorption and tensile test. The results show that oMMT and the IPNs of polyurethane and epoxy resin exhibit synergistic effect on the phase structure and morphology of the IPNs nanocomposites. The addition of oMMT to the PU/EP IPNs matrix provides two fold benefits to the properties of the IPNs nanocomposites. oMMT has not a distinct effect on chemical structure of PU/EP IPNs but promotes the compatibility and phase structure of the IPNs, and the forced compatibility of PU and EP in interpenetrating process improves the dispersion degree of oMMT. Both the mechanical properties and water resistance of the PU/EP IPNs nanocomposites are superior to those of the pure PU/EP IPNs.     

Computer simulation method for calculating concentration profiles in polyurethane/polystyrene interpenetrating polymer network membranes

Interpenetrating polymer networks (IPNs) of polyurethane (PU) and polystyrene (PS; 90/10 and 75/25) were synthesized by the condensation reaction of castor oil with methylene diisocyanate and styrene, with benzoyl peroxide as an initiator. The IPN membranes were characterized for physicomechanical, optical, and X‐ray diffraction properties. Computer‐simulated concentration profiles of aqueous salt solutions through PU/PS IPN membranes were generated with Fick's second‐order differential equation, and the results were examined in terms of diffusion anomalies. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 122–128, 2003     

Studies on interpentrating polymer networks of polyurethane and polybismaleimide. I. Polyurethane and bismaleimide-urethane copolymer

The interpenetrating polymer networks (IPNs) of polyurethane (PU) and the mixture of bismaleimide (BMI) and the 2-hydroxylethyl methacrylate (HEMA)-terminated PU prepolymer (HPU) were prepared by using a simultaneous polymerization technique. The effects of the PU molecular weight and the amounts of the PU on the mechanical properties, thermal stability, and dynamic mechanical properties are discussed. The IPNs exhibited superior ultimate tensile strength as the polyol of PU and HPU in the IPNs is based on poly(tetramethylene oxide) (PTMO) glycol of molecular weight 1000 (PTMO1000). Izod impact property of the IPNs indicated that the PU(PTMO1000)/BMI-HPU(PTMO1000) IPNs had much more significant improvement than that of the PU(PTM02000)/BMI-HPU(PTMO2000) IPNs. Better thermal stability was shown by the IPNs as compared with the components of the networks, i.e. PU or BMI-HPU copolymers. The dynamic mechanical analysis (DMA) indicates that these IPNs show various shifts in the loss moduli(E) at the high and low temperature transition peaks for various molecular weight of the polyol employed in the PU. Better compatibility between BMI and PU was found as the PU(PTMO1000) was employed.To whom all correspondence should be addressed.     

Recent studies on interpenetrating polymer networks

Recent investigations on interpenetrating polymer networks (IPNs) have included two component IPNs from polyurethanes and poly(methacrylates) and two component IPNs from polyurethanes and epoxies. All the IPNs were prepared by the simultaneous polymerization technique (SIN-IPNs). Two types of IPNs, polyurethane-poly(methyl methacrylate) (PU/PMMA) and polyurethane-poly(methyl methacrylate-methacrylic acid) (PU/PMMA-MAA) were prepared. Improved phase miscibility and decreasing extent of phase separation was observed in both types of IPNs with increasing the NCO/OH ratio, decreasing molecular weight of the polyol in the PU and introduction of charge groups. A comparison was made between full-IPNs, pseudo-IPNs, graft copolymers and related homopolymers from polyurethanes and epoxies. Increased compatibility in full-IPNs and graft copolymers was observed by means of DSC, SEM and was also further substantiated by a shift toward single T_gs as determined by dynamic mechanical spectroscopy. The introduction of opposite charge groups in two-component IPNs from polyurethanes and epoxies led to improved compatibility (no phase separation) and enhanced mechanical properties.     

Damping properties of interpenetrating polymer networks of polyurethane‐modified epoxy and polyurethanes

Interpenetrating polymer networks (IPNs) were prepared from polyurethane (PU)‐modified epoxy with different molecular weight of polyol and polyurethanes based on the mixture of polydiol and polytriol by a one‐shot method. Two types of PU‐modified epoxy: PU‐crosslinked epoxy and PU‐dangled epoxy were synthesized, and the effects of the different molecular weights of polyol in the PU‐modified epoxy/PU IPNs on the dynamic mechanical properties, morphology, and damping behavior were investigated. The results show that the damping ability is enhanced through the introduction of PU‐modified epoxy into the PU matrix to form the IPN structure. As the molecular weight of polyol in PU‐modified epoxy increases, the loss area (LA) of the two types of the IPNs increases. PU‐dangled epoxy/PU IPNs exhibit much higher damping property than that of the PU‐crosslinked epoxy/PU IPNs with 20 wt % of PU‐crosslinked epoxy. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 328–335, 1999