用热焓松弛行为研究聚苯醚和改性聚苯醚共混体系的相容性

用DSC分别探讨了苯酰化聚苯醚(PPO)(BA~(31.0)-PPO和BA~(43.4)-PPO)/PPO共混体系的热焓松弛变化规律与差异.发现已知是相容体系的BA~(31.0)-PPO/PPO在低于T_g等温退火过程中只出现一个吸热峰;典型的相容体系PPO/PS也表现出类似的行为.而未知相容性的BA~(43.4)-PPO/PPO在等温退火过程中出现两个吸热峰,此两峰的T_p值随退火时间的变化类似于各纯组分相应条件下的变化.电子显微镜结果表明,BA~(43.4)-PPO/PPO是相分离体系.因此对T_g非常接近的较刚性主链的PP0及其改性物的共混体系可用热焓松弛行为确定其相容性.

MISCIBLLITY OF PPO AND ITS DERIVATIVES BY ENTHALPY RELAXATION

DSC was used to study the changes of enthalpy relaxation behavior of blends of poly (2,6-dimethyl-1,4-phenylene oxide) (PPO)and benzoylated PPO(31. 0 mol% and 43. 3 mol% of benzoyl group respectively) (BA31.0-PPO, BA43.4-PPO). It was found that for the miscible blend of BA31.0-PPO/PPO, there was only one endothermal peak during the isothermal annealing. This behavior was very similar to that of PPO/PS blend. But for the BA43.4-PPO/ PPO blend whose miscibility was unknown, there were two endothermal peaks during the annealing , and the Tg values of the two peaks were very close to those of pure components of BA43.4-PPO or PPO. The results of SEM micrographs indicated that BA43.4-PPO/PPO was two phase system. So the enthalpy relaxation can be used to study the compatible properties of blend of PPO and its derivatives which have similar Tg.