PMMI/PVDF共混体系相分离的时温依赖性

TIME AND TEMPERATURE DEPENDENCE OF PHASE-SEPARATION BEHAVIOR FOR POLY(N-METHYL METHACRYLIMIDE)/POLY(VINYLIDENCE FLUORIDE) BLENDS

用小角激光光散射(SALLS)研究了聚(N-甲基甲基丙烯酰亚胺)/聚偏氟乙烯(PMMI/PVDF)共混体系的相分离行为.通过升温法获得了PMMI/PVDF体系的浊点温度,发现体系的浊点温度强烈依赖于升温速率,呈明显的非线性关系,即升温速率大于1 K.min-1时,升温速率是影响I(t)的唯一因素;升温速率较小时,高分子链松弛速率的差别得以体现,则该情况下升温速率与松弛速率共同影响浊点温度.该体系具有典型的最低临界共溶温度(LCST)特征.恒温法相分离结果表明,在实验温度范围内该体系相分离行为对温度的依赖性遵循时温叠加(time-temperature superposition,TTS)原理.

The liquid-liquid phase-separation(LLPS) behavior of poly(N-methyl methacrylimide)/poly(vinylidene fluoride)(PMMI/PVDF) blends was studied by using small angle laser light scattering(SALLS),and the time-temperature dependence of phase-separation behavior was discussed.According to examining the dependence of cloud points(T_c) on heating rate for PMMI/PVDF blends,it was found that T_c decreased as the temperature droped nonlinearly.When the heating rate was higher than 1.0 K/min,only the heating rate could a...