聚甲基丙烯酸甲酯/聚丙烯酸乙酯互穿网络体系相逆转、相态结构与性能的研究

本文研究了聚甲基丙烯酸甲酯/聚丙烯酸乙酯互穿网络体系(PMMA/PEALIPN)相分离和组分配比对其相逆转、相态结构及动态力学性能的影响.同时,对LIPN与其相应的混合乳液体系的结构和阻尼特性进行比较.结果表明,LIPN体系由于存在网络的相互贯穿,与混合体系相比其相分离程度低,出现精细结构,密度较高.当丙烯酸乙酯(EA)含量低时,PEA呈细胞结构分散在PMMA连续相中,随EA量的增加,体系出现相逆转并在EA体积含量为48％至86％范围内呈两相连续,各种性能发生突变和具有高阻尼特性.实数模量的实验点服从用Halpin-Tsai-Nielsen模量上、下限方程和描述两相连续的对数混合律三个方程结合计算的理论曲线.

PHASE INVERSION, MORPHOLOGY AND PROPERTIES OF POLY (METHYL METHACRYLATE)/POLY (ETHYL ACRYLATE) LATEX IPN

The phase separation and the effect of composition on phase inversion, phase structure and dynamic mechanical properties of PMMA/PEA LIPN have been investigated. A comparison of the structure and damping properties between LIPN and mixture system has also been done. The results suggest that the segregation degree of components is lower and the density is higher in LIPN than that in mixture system due to the interpenetration of one network into the other. A refined structure is revealed in LIPN, but not in mixture system. At low EA content the PEA with cell structure dispersed in the PMMA continuous phase, while as EA content continuously increases, the phase inversion will occur and over the range of EA volume fraction from 48% to 86% the PMMA and PEA both form co-cotinuous phase where several properties change very rapidly, the higher damping property appears. The calculated curve by using a combination of upper and lower bounds of Halpin-Tsai-Nielsen equation and logarithmic rule of mixtures fits the experimental data very well.