PPESK/PES共混物热性能及动态机械性能研究

采用熔融共混法制备了不同重量比例的新型含二氮杂萘酮结构聚芳醚砜酮(PPESK)与聚醚砜(PES)共混物.利用热失重(TGA)及动态热机械仪(DMTA)对该共混物的热性能及动态机械性能进行了研究.研究结果表明,在氮气氛围中,PPESK热分解分为两步反应进行,反应级数n=1,说明PPESK在氮气氛围中的热分解反应类型与β(升温速率)无关而与材料物性有关;采用Ozawa方法得出在15%热失重前,热分解活化能的平均值为240 kJ/mol;随着升温速率的提高,PPESK热降解速率有减缓趋势.在280℃以前,PPESK储能模量值随温度变化较小,保持在较高值,温度在280~330℃之间,储能模量值降低幅度突变.另外,PPESK中加入PES会降低其储能模量值及其热稳定性.

A STUDY ON THERMAL AND DYNAMIC MECHANICAL PROPERTIES OF PPESK/PES BLENDS

A series of blends with varies compositions was prepared by melt-mixing on the basis of poly_(phthalazinone ether sulfone ketone)(PPESK) and poly(ether sulfone)(PES).The thermal stability of PPESK/PES blends was characterized by kinetic studies using dynamic thermogravity in nitrogen atmosphere.The dynamic mechanical properties of blends were carried out with DMTA.The results showed that the thermal degradation displayed a two-step reaction and the degradation of PPESK was found to be a first order reaction in nitrogen.It suggested that the degradation of PPESK in nitrogen was just related with the material properties not with the rate of temperature increasing.The dynamic data such as the apparent activation energy before 15% loss mass,E_a of 240 kJ/mol,were analyzed using Ozawa method.The thermal degradation rate of PPESK was slowed with increasing heating rate.Besides,the storage modulus of PPESK decreased a little with temperature increasing before 280℃,however,it had a remark drop in the temperature range of 280℃ to 330℃.The presence of PES in PPESK resin reduced the storage modulus and thermal stability.