不同单体对合成聚芳醚酮酮(PEKK)结构与性能的影响研究

以1,4-二(4-苯氧基苯甲酰基)苯(p-EKKE)、1,3-二(4-苯氧基苯甲酰基)苯(m-EKKE)、二苯醚(DPE)分别与对苯二甲酰氯(TPC)、间苯二甲酰氯(IPC)亲电共缩聚,合成全对位、全间位、对间位取代及交替聚芳醚酮酮(p-PEKK、i-PEKK、p/i-PEKK、a-PEKK),用FT-IR、DSC、WAXD、TG、SEM等技术对p-EKKE和m-EKKE以及PEKKs的结构与性能进行了分析表征.结果表明,随着1,3-苯基含量的增加,共聚物的熔融温度(Tm)和玻璃化转变温度逐渐降低,而热分解温度变化不大;p/i-PEKK交替共聚物较之于无规共聚物,有较好的链规整性和较高的结晶度;WAXD分析表明,共聚物p-PEKK的结晶衍射峰和小分子模型化合物p-EKKE基本相同,同属正交晶系,全间位取代的i-PEKK在熔融冷却过程中很难再次结晶,转变为非晶聚集态,其2θ角和m-EKKE针状结晶基本相同,属三斜晶系.

SYNTHESIS, STRUCTURE AND PROPERTIES OF POLY(ARYL ETHER KETONE KETONE) S WITH DIFFERENT MONOMERS

A series of high molecular weight alternative and random poly(aryl ether ketone ketone) copolymers were prepared by low-temperature solution poly-condensation,with 1,4-bis(4-phenoxybenzoyl)benzene(p-EKKE),1,3-bis(4-phenoxybenzoyl)benzene(m-EKKE),diphenyl ether(DPE) and terephthaloyl chloride(TPC) or isophthaloyl chloride(IPC),respectively.The inherent viscosities(η_inh) of resulting copolymers were in the range of 0.63～1.08 dL/g.The chemical structure of p-EKKE,m-EKKE and PEKKs were confirmed by FT-IR.The thermal properties of copolymers were obtained by DSC and TG.The DSC results indicated that the melt temperature(T_m) and the glass transition temperature(T_g) decreased with increasing the amount of meta-phenylene substituted in the main chain.The TG results showed that the copolymers had excellent thermo-oxidative stability,being stable above 530℃,which was affected slightly by the amount of meta-phenylene substituted in the main chain.The alternative copolymer b-PEKK has better order and higher crystallinity than random copolymers.WAXD showed that copolymer p-PEKK and its model compound had the same crystallization diffraction spectra corresponding to a rhombic system.While the morphology of the copolymer i-PEKK and the corresponding model compound showed needle crystals,which belonged to an anorthic system.i-PEKK was difficult to crystallize again in the course of melting,and it was in an amorphous state.