环氧树脂/聚砜共混体系相结构的调控研究——环氧预聚物分子量的影响

研究了不同分子量的环氧预聚物对双酚A型双官能团环氧树脂 /聚砜 (PSF) /固化剂 (二氨基二苯基砜 ,DDS)体系相分离结构的影响 .通过红外光谱 (FTIR)和动态热机械分析 (TMA)对反应转化率、玻璃化温度以及固化温度的关系的研究 ,表明环氧预聚物分子量较小时 ,凝胶点和玻璃化是影响相结构的关键因素 ;环氧分子量较大时 ,环氧扩链后粘度的变化则成为抑制相分离的重要因素 .电子显微镜 (SEM)结果表明改变环氧预聚物分子量可以达到调控相结构的目的 ,随着预聚物分子量的增大 ,体系的微区尺寸减小 .

PHASE STRUCTURE CONTROL OF EPOXY/POLYSULFONE BLENDS BY MOLECULAR WEIGHT OF EPOXY RESINS

Phase separation during the curing reaction in blends of diglycidly ether of bisphenol A,polysulfone and diaminodiphenylsulfone(DDS,curing agent) was studied. Effects of epoxy resins with different molecular weight on phase structure of the blends were investigated. The relation between the degree of conversion and reaction time revealed that vitrification and gelation greatly affected the formation of phase structure in the low molecular weight epxoy systems. When T g of the epoxy-rich phase went up to the reaction temperature, both reaction and phase separation were suppressed. While in the high molecular weight epoxy systems, the viscosity increasing of epoxy resins played an important role. Although the degree of conversion of the epoxy-rich phase did not reach the gel point after 24h precure, phase separation was suppressed due to the high viscosity of the systems. SEM results showed that the desired phase structure could be achieved by using epoxy resins with different molecular weight.