环氧树脂/丙烯酸酯互穿网络聚合物及其流变性能研究

采用甲基六氢邻苯二甲酸酐( MeHHPA)作为新型脂环族环氧树脂(CER)的固化剂,选用过氧化二异丙苯为三羟甲基丙烷三甲基丙烯酸酯( TMPTMA)的引发剂,制备了一种新的CER/TMPTMA互穿网络聚合物( IPNs).通过扫描电子显微镜表征并证实了IPNs的形成过程.研究发现,由于TMPTMA的自由基聚合反应先于C...     

外电场对CER/TMPTMA IPNs形成过程的在线监测

利用自制装置研究了脂环族环氧树脂(CER)/三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)互穿网络聚合物(IPNs)的固化过程.通过在线测试CER/TMPTMA体系固化过程中的交流电阻和电容,发现电阻和电容的变化反映出CER/TMPTMA体系的固化过程是一个分步IPNs的形成过程,而且电阻和电容变化趋势与体系的粘度、离子浓度以及偶极子的数量息息相关.利用自制电极和装置可以远距离在线监测热固性树脂的固化过程,在外磁场干扰下,利用CER/TMPTMA固化体系的电阻波动可以表征体系的固化反应情况.     

接枝改性环氧树脂/不饱和聚酯互穿聚合物网络的研究

研究了双酚A双烯丙基醚(ABE)对脂环族环氧树脂(CER)/三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)分步互穿聚合物网络(SIPNs)的改性.利用扫描电子显微镜(SEM)考察了改性SIPNs形成的过程及最终固化物的微观结构,在此基础上研究了ABE用量对CER/TMPTMA SIPNs固化过程中的凝胶时间、最终固化物的力学性能及介电性能的影响.结果表明,ABE的加入没有改变CER/TMPTMA所形成SIPNs的结构,制得的改性SlPNs没有出现明显相分离现象.随着ABE用量的增加,改性SIPNs的冲击性能逐渐提高;当ABE用量为lO份时,改性SIPNs的弯曲性能最佳.ABE的加入还改善了改性SIPNs的介电性能,提高了改性SIPNs的电气强度.当ABE用量为20份时,改性SIPNs的电气强度最高.     

助交联剂三（甲基丙烯酸）三羟甲基丙烷酯在丁腈橡胶/热塑性聚酯弹性体共混物中的应用

研究了助交联剂三（甲基丙烯酸）三羟甲基丙烷酯（TMPTMA）的用量对丁腈橡胶/热塑性聚酯弹性体共混物性能的影响。结果表明,助交联剂TMPTMA不仅有加快硫化速率的作用,也具有一定的增塑效果,使混炼胶的门尼黏度降低,改善了胶料的加工性能;随着TMPTMA用量的增加,丁腈橡胶/热塑性聚酯弹性体共混物的拉伸强度、撕裂强度、100%定伸应力及硬度增大,而扯断伸长率减小,耐低温和耐老化性能下降;随着TMPTMA用量的增加,共混物的磨耗体积先减小后增大,耐油性能得到改善。     

TMPTMA交联改性聚丙烯酸酯乳液的合成与性能

以三羟甲基丙烷三甲基丙烯酸酯（ TMPTMA ）为内交联单体,苯乙烯（ St ）、甲基丙烯酸甲酯（ MMA）、丙烯酸丁酯（ BA）和甲基丙烯酸（ MAA）为共聚单体,采用半连续核壳乳液聚合工艺合成了自交联聚丙烯酸酯乳液（ T-PAE）。考查了TMPTMA添加量与添加方式对乳液聚合稳定性以及涂膜性能的影响。研究发现：随着TMPTMA含量的增加,T-PAE乳液聚合的稳定性降低,聚合凝胶率增大,乳胶粒的平均粒径下降；涂膜的耐介质性能和交联密度相应提高,合适的TMPTMA加入量为总单体质量的0．5%~1．0%。     

蓖麻油型聚氨酯/PS同步IPNs的协同效应研究

采用同步互穿网络技术,制备了一系列蓖麻油型聚氨酯/聚苯乙烯（COPU/PS）互穿网络聚合物（IPNs）,研究了它们的力学性能和溶胀性能.结果表明,当PS/COPU、BPO（过氧化二苯甲酰）/St（苯乙烯）质量分数分别为30%和1.5%时,三羟甲基丙烷（TMP）和蓖麻油羟基的摩尔比、NCO与OH的摩尔比分别为0.2和1.3时,互穿网络材料的相容性好,协同效应明显,此时力学性能最佳.当COPU/PS的IPNs材料中PS质量分数为20%～40%时,由于两相的互穿作用,使二甲苯对IPNs材料的溶胀趋缓;并且随着交联剂TMP的增加,平衡溶胀增重率增幅变小,到TMP和蓖麻油的羟基摩尔比值大于0.2后,平衡溶胀增重率基本不变.     

香草醇基环氧树脂的合成、固化动力学及性能

以可再生香草醇为原料,合成了一种生物基环氧树脂（DGEVA）。通过使用甲基六氢苯酐（MeHHPA）作为固化剂,制备了一种新型的生物基环氧树脂交联网络（DGEVA/MeHHPA）。对其非等温固化动力学、热性能、热机械性能、机械性能和微观形貌结构进行了系统的研究,并用商用的石油基双酚A型环氧树脂组成的石油基环氧树脂体系（DGEBA/MeHHPA）进行对比。结果表明：DGEVA/MeHHPA和DGEBA/MeHHPA具有相似的固化反应活性。DGEVA/MeHHPA具有可以与DGEBA/MeHHPA相媲美的综合性能：玻璃化转变温度为82.2℃;拉伸强度和拉伸模量分别是 (66.7±6)MPa和 (2.8±0.1)GPa;T_d5%、T_d10%和T_dmax分别是242.4℃、284.9℃和392.4℃。此外,DGEVA/MeHHPA在形变过程中发生了塑性变形而吸收了更多的断裂能。DGEVA刚性骨架和低分子量带来的潜在高交联密度赋予了DGEVA优异性能,具有在实际应用中替代石油基环氧树脂的应用潜力。     

聚苯乙烯互穿聚合物网络研究进展

综述了聚苯乙烯互穿聚合物网络的研究进展,阐述了分步互穿聚合物网络、同步互穿聚合物网络、半互穿聚合物网络和胶乳互穿聚合物网络的制备方法,介绍了组成和制备方法对PS互穿聚合物网络的相态结构和互穿聚合物网络相容性的影响。阐述了PS互穿聚合物网络的组成和结构对于力学性能、热力学性能、流变性能、气体透过率和吸附性的影响,最后综述PS互穿聚合物网络存在的问题及发展趋势。     

反应型大分子抗氧剂的合成及其在EPDM中的抗氧化性能

通过自由基引发的三羟甲基丙烷三甲基丙烯酸酯（TMPTMA）与2⁃巯基苯并咪唑（MB）反应合成了一种反应型大分子抗氧剂TMPTMA/MB。通过傅里叶变换红外光谱、X射线光电子能谱和元素分析证实了TMPTMA/MB的化学结构,并研究了TMPTMA/MB对EPDM硫化特性、拉伸性能及抗氧化性能的影响,结果表明,TMPTMA/MB消耗了过氧化物分解产生的烷氧自由基并接枝到EPDM分子链上,从而减缓了橡胶的硫化速度并降低了交联程度,但接枝的TMPTMA/MB增加了外力作用下分子链运动的内摩擦,提高了EPDM的拉伸性能,另外,接枝到EPDM分子链的TMPTMA/MB具有较高的抗迁移性,由此大幅提高了EPDM的抗氧化性能。     

PUR/EP/PPGDA三元IPN的光电子能谱研究

用X射线光电子能谱（XPS）分析了以聚氨酯（PUR）为第一网络的PUR／环氧树脂／聚－β－丙二醇二丙烯酸酯互穿聚合物网络（PUR／EP／PPGDA IPN）弹性体的表面元素分布，并用氩离子刻蚀进行材料内部元素分析。结果表明，三元IPN弹性体中主要元素C、O、N、Cl在材料表面和内部分布明显不一致，这种差异表明形成IPN后，三种组分聚合物在材料的表面和内部的分布是不均匀的，这种不均匀性与三种聚合物的比例有关。     

On-line monitoring of cycloaliphatic epoxy/acrylate interpenetrating polymer networks formation and characterization of their mechanical properties

The novel interpenetrating polymer networks (IPNs) based on cycloaliphatic epoxy resin (CER) containing cyclohexene oxide groups and tri-functional acrylate, trimethylol-1, 1, 1-propane trimethacrylate (TMPTMA) were synthesized. The formation of the IPNs was on-line monitored by means of polarizing optical microscope, time-resolved light scattering and Fourier transform infrared spectroscopy. The morphological and mechanical properties of the resultant IPNs were investigated and evaluated with scanning electron microscopy (SEM) and dynamical thermal mechanical analysis (DTMA), respectively. The on-line monitoring results showed that during the course of the IPNs formation, the TMPTMA component was cured more quickly than the CER component, leading to the formation of the sequential IPNs. During the early curing stage, there were the phase separation phenomena in the CER/TMPTMA system. The SEM results revealed that although there were some slight phase separation phenomena in the CER/TMPTMA system in the early curing stage, the resultant IPNs displayed the homogeneous structures and did not show the apparent phase separation morphology. The DTMA results revealed that the resulting IPNs exhibited rather higher modulus and denser cross-linking network structure than the neat CER system.     

Morphology and thermal and dielectric behavior of cycloaliphatic epoxy/trimethacrylate interpenetrating polymer networks for vacuum‐pressure‐impregnation electrical insulation

Vacuum pressure impregnation has been known as the most advanced impregnation technology that has ever been developed for large and medium high‐voltage electric machines and apparatuses. We developed one new type of vacuum‐pressure‐impregnation resin with excellent properties by means of a novel approach based on in situ sequential interpenetrating polymer networks resulting from the curing of trimethacrylate monomer [trimethylol‐1,1,1‐propane trimethacrylate (TMPTMA)] and cycloaliphatic epoxy resin (CER). In this study, the influence of the concentrations of the components and their microstructures on their thermal and dielectric behaviors were investigated for the cured CER/TMPTMA systems via atomic force microscopy, dynamic mechanical analysis, thermogravimetric analysis, and dielectric analysis. The investigation results show that the addition of TMPTMA to the CER–anhydride system resulted in the formation of a uniform and compact microstructure in the cured epoxy system. This led the cured CER/TMPTMA systems to show much higher moduli in comparison with the pure CER–anhydride system. The thermogravimetric analysis results show that there existed a decreasing tendency in the maximum thermal decomposition rates of the cured CER/TMPTMA systems, which implies that the thermal stability properties improved to some extent. The dielectric analysis results show that the cured CER/TMPTMA systems displayed quite different dielectric behaviors in the wide frequency range 0.01 Hz–1 MHz and in the wide temperature range 27–250°C compared with the cured CER–anhydride system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Morphologies and applied properties of free radical/cationic UV‐cured CPUA/TMPTMA/CER composite films

A UV‐cured composite film was prepared by free free‐radical photopolymerization from a blend containing oligomer cycloaliphatic polyurethane acrylate (CPUA) and reactive diluent trimethylolpropane trimethaacrylate (TMPTMA) with the same weight (coded as UT) in the presence of free free‐radical photoinitiator Irgacure 754. It was proved to be a homogeneous system featuring only one phase by means of scanning electron microscopy (SEM). Cycloaliphatic epoxy resin (CER) was introduced to enhance mechanical properties of the UV‐cured UT composite film in the presence of cationic photoinitiator Irgacure 250, and a series of UV‐cured CPUA/TMPTMA/CER composite films with different component ratios were prepared by free radical/cationic hybrid UV UV‐curing technique. Results of conversion curves, SEM, and Fourier‐ transform infrared spectroscopy illustrated that UT was cured faster than CER, leading to dynamically asymmetric photopolymerization‐induced phase ‐separation behaviors. The thermal and mechanical properties were evaluated via thermal degradation analysis, dynamic mechanical analysis, and stress–strain curves. Surface properties such as pencil hardness, pendulum hardness, shrinkage rate, contact angle, flexibility, and glossiness were also studied. All these measurements revealed that component ratios, intermolecular attractions, photopolymerization velocities, and viscosities had remarkably influenced on the morphologies and applied properties of UV‐cured composite films, and interpenetrating polymer network films had better comprehensive performances than other UV‐cured composite films with different microstructures. POLYM. COMPOS., 36:1177–1185, 2015. © 2014 Society of Plastics Engineers     

交联密度对HNBR/聚甲基丙烯酸正丁酯IPN阻尼性能的影响

用序列法制备氢化丁腈橡胶(HNBR)/聚甲基丙烯酸正丁酯(PnBMA)互穿聚合物网络(IPN)材料,通过改变两网络的硫化剂用量得到不同交联密度的HNBR/PnBMA IPN。采用动态粘弹谱仪测试IPN的阻尼性能,结果表明HNBR/PnBMA IPN材料的阻尼特性与交联密度密切相关。随着第一网络交联密度的增加,阻尼曲线逐渐由双峰转变为单峰,阻尼峰宽降低。第二网络交联密度的增加使阻尼曲线整体下降,双峰形态不变。通过改变两网络的交联密度可调整阻尼峰的位置、宽度及阻尼峰值。     

助交联剂在氢化丁腈橡胶中的应用研究

研究了添加不同用量的助交联剂齐聚酯和三甲基丙烯酸三羟甲基丙烷酯(TMPTMA)氢化丁腈橡胶的硫化特性、力学性能,并对比了两种助交联剂对氢化丁腈橡胶的硫化特性、力学性能、老化性能、高温拉伸性能、耐磨性能和加工性能的影响。结果表明：随着齐聚酯和TMPTMA含量的增加,橡胶的扭矩增大,硫化时间缩短;拉伸强度基本不变,硬度、100%定伸应力、撕裂强度逐渐提高,拉断伸长率、回弹性减小。与添加齐聚酯的橡胶相比,添加TMPTMA橡胶的扭矩较大,硫化时间较短;对比添加齐聚酯和TMPTMA的橡胶,它们的力学性能、老化性能、高温拉伸性能和耐磨性能都非常接近,可见它们在硫化过程中的作用原理相似。由橡胶加工分析仪可知,添加TMPTMA橡胶的储能模量较小,损耗因子较大。     

Radiation synthesis and environmental responsiveness of semi‐interpenetrating polymer networks composed of poly(dimethyl–aminoethyl methacrylate) and poly(ethylene oxide)

Semi‐interpenetrating polymer networks (semi‐IPNs) composed of poly(dimethyl–aminoethyl methacrylate) (PDMAEMA) and poly(ethylene oxide) (PEO) were synthesized by γ‐radiation; three semi‐IPNs with 80 : 20, 90 : 10, and 95 : 5 weight ratios of DMAEMA/PEO were obtained by use of this technique. The gel–dose curves showed that the hydrogels were characterized by a structure typical of semi‐IPNs and the results of elemental analysis supported this point. The temperature‐induced phase transition of semi‐IPNs with the composition of 95 : 5 was still retained, with the lower critical solution temperature of PDMAEMA shifting from 40 to 27°C. The temperature sensitivity of the other two semi‐IPNs gradually disappeared. The pH sensitivity of three semi‐IPNs was still retained but the pH shifted slightly to lower values with increasing PEO content in the semi‐IPNs. The effect of PEO content in semi‐IPNs on their environmental responsiveness was discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2995–3001, 2004     

Reaction kinetics of irradiation- prepolymerized methyl methacrylate-polyurethane interpenetrating polymer networks by FTIR

The reaction kinetics of irradiation-prepolymerized MMA-PU (polyether) IPNs have been studied by FTIR. The results indicate that the polymerization of each component in the IPN follows its normal distinct reaction mechanism with no mutual interference. Increasing the concentration of TMPTMA (crosslinking agent of PMMA) increased the formation rate of PMMA, while the formation rate of PU networks remained almost the same. Increasing the concentration of TMP (crosslinking agent of PU) increased the formation rate of PU, while the formation rate of PMMA networks decreased. The formation rate of PU was obviously faster than that of PMMA. A theory for the cage effect of the PU network has been proposed.     

Use of SAXS to Characterize the Morphology of Poly(polyethylene glycol diacrylate)/Epoxy Resin Interpenetrating Networks

Interpenetrating polymer networks (IPNs) have been synthesized from prepolymers that form miscible blends. All IPNs made from polyacrylate ((polyethylene glycol diacrylate), PEGDA) and epoxy (diglycidyl ether of bisphenol A, DGEBA) can be made in phase separated states by incorporating crosslinks. However, blends of these prepolymers, having a negative Flory–Huggins interaction parameter, are highly miscible. This indicates that formation of IPNs favours phase separation relative to blends. The microphase separation characteristics in the PEGDA/DGEBA IPNs were determined using small-angle X-ray scattering (SAXS). The Debye–Bueche and Guinier methods were used to calculate the correlation lengths of the segregated phases existing in the PEGDA/DGEBA IPNs. The results from SAXS showed that the size of the phase segregation zones changed with composition from about 50 to 100Å. © of SCI.     

Studies and characterization of RESOL/VAc–EHA/HMMM IPN systems in aqueous medium

Resol was solution‐blended with vinyl acetate‐2‐ethylhexyl acrylate (VAc–EHA) resin in an aqueous medium, in varying weight fractions, with hexamethoxymethylmelamine (HMMM) as a crosslinker and the data were compared with a control. The present work was aimed to obtain an optimum combination of high‐temperature resistance by synthesis of an interpenetrating network (IPN) of the resins. The control gave a semi‐IPN system, in which the resol crosslinked, while the acrylic did not, whereas the blend, where HMMM was the crosslinker, gave a full‐IPN system. FTIR spectra of the blends of resol/VAc–EHA/HMMM indicated the formation of new stretching, which was generated due to crosslinking reactions among VAc–EHA and the crosslinker HMMM. TGA showed that, with an increase in the VAc–EHA percent in semi‐IPNs, the decomposition temperature decreased gradually, whereas in case of full‐IPNs, the decomposition temperature increased with increase in the VAc–EHA percent. However, the full‐IPNs had a higher decomposition temperature than that of the semi‐IPNs, at the same resol/(VAc–EHA) ratio. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3581–3588, 2002