环氧树脂/氨酯丙烯酸酯树脂互穿聚合物网络生成动力学研究

POLYMERIZATION KINETICS OF INTERPENETRATING\= POLYMER NETWORKS COMPOSED OF EPOXY RESIN\= AND URETHANE ACRYLATE RESIN

用ＦＴＩＲ跟踪研究了由不同分子量聚氧化丙烯（ＰＰＯ）合成的氨酯丙烯酸酯树脂（ＵＡＲ）／环氧树脂（ｅｐｏｘｙ）同步互穿网络（ＳＩＮ）的生成动力学．结果表明，在聚合反应初期（转化率＜０４）环氧基和不饱和双键的转化率均和反应时间呈近似线性关系，聚合反应主要由单体的扩散控制；由不同分子量ＵＡＲ合成的ｅｐｏｘｙ／ＵＡＲＳＩＮ的生成动力学有较大差异，与ＳＩＮ形成过程中的形态发展有关．通过不同用量的ＡＩＢＮ，可以调节ＵＡＲ网络的形成速度，导致ＳＩＮ中两个网络的生成顺序发生改变．

A series of simultaneous interpenetrating polymer networks (SINs) composed of epoxy resin(epoxy) and urethane acrylate resin(UAR) with different molecular weights were synthesized and characterized. The polymerization kinetics of both network formations was monitored by using Fourier transform infrared spectroscopy(FTIR) for preparing the toughed epoxy or reinforced UAR materials. It was found that during the course of synthesis, the polymerization rate for formation of both networks is almost independent of the concentration of reactants especially at the early stage of reaction. The two pairs of reactants interfere with each other appreciably in the SIN systems, although they follow different polymerization mechanisms, i.e., step polymerization and free radical polymerization. All these unusual polymerizaion kinetics behaviors observed could be well correlated with the changes of viscosity and morphology of the systems. UAR network synthesized with difunctional polyoxypropylene polyol (PPO) having shows a partial microphase separated morphology. Thus, the SIN consisting of epoxy and such a UAR not only exhibits a phase separated behavior between the two networks but also a microphase separation for UAR giving rise to even more depressed reaction rates for network formation. It is clear that for these SIN systems the polymerization kinetics is mainly controlled by diffusion effect. Furthermore, the sequence of both network formations has been adjusted by changing the amount of initiator for UAR.\=