侧链含酯基的聚对苯撑的合成及其水解性研究  

Synthesis and Hydrolysis of Poly(p-phenylene)s with Ester Pendant Groups

作　　者：毛丹波 王跃川[1] 

机构地区：[1]四川大学高分子科学与工程学院高分子材料工程国家重点实验室,成都610065

出　　处：《工程塑料应用》2016年第3期12-17,共6页Engineering Plastics Application

摘　　要：以自制的2,5- 二氯苯甲酸甲酯和2,5- 二氯苯甲酸异辛酯为单体,采用Ni/Zn 催化体系,合成了侧基分别为甲酯基、异辛酯基的聚对苯撑及其共聚物,利用凝胶渗透色谱法和差示扫描量热法测试了3 种聚合物的分子量及玻璃化转变温度（Tg）,并测试了它们在有机溶剂中的溶解性.结果表明,利用该催化体系能得到一定分子量的聚对苯撑均聚物和共聚物,两种单体按投料比进行了共聚;通过调整单体投料比,可以调控共聚物的Tg 在–7.7-130℃之间变化,当单体投料比为1∶1（ 物质的量之比） 时,共聚物的Tg 为87.7℃;当引入大支链侧基异辛酯基时,聚对苯撑在有机溶剂中的溶解性大大提高.由于侧基酯基水解的难易程度不同,通过一定的水解条件考察均聚物和共聚物的水解特性,发现在一定碱性条件下,含甲酯基的均聚物30 min 内已全部水解,而含异辛酯基的均聚物在该时间内几乎不水解,水解完全需要12 h.对单体投料比为1∶1 的共聚物进行水解,发现相同条件下完全水解只需75 min.水解后侧基羧基的存在可为后续的改性比如交联提供反应活性点.Taking two ester substituted 2,5-dichlorobenzoates(substituent:methyl,iso-octyl) made by self as monomers, the poly(p-phenylene)s with methyl ester or iso-octyl ester pendant group and their copolymer were synthesized with Ni-catalyzed/Zn-mediated system. The molecular weight and glass transition temperature (Tg) of the three kinds of polymers were characterized by GPC and DSC,their solubility in organic solvents were also tested. The results show that poly(p-phenylene) homopolymers and copolymer with a certain molecular weight were obtained through Ni-catalyzed/Zn-mediated system,and also the two monomers are copolymerized on the basis of charge ratio. By adjusting different monomer charge ratios,Tg of the copolymer can be tuned from –7.7℃to 130℃,when the charge ratio is 1∶1(mole ratio),Tg of the copolymer is 87.7℃. The solubility in organic solvents are greatly enhanced by introducing bulky iso-octyl ester pendant group into poly(p-phenylene). Moreover,the hydrolysis characteristics of ester pendant groups are different because of steric hindrance,and the hydrolyses of the homopolymers were investigated in a cer-tain alkaline condition. The homopolymer with methyl ester pendant group is absolutely hydrolyzed in 30 min while the homopoly-mer with isooctyl-ester pendant group is almost not,in contrast,it took 12 h for the latter tofinish the hydrolysis. Besides,the hy-drolysis experiment of the copolymer with charge ratio being 1∶1 was done,it is found that the hydrolysis is completed in 75 min under same conditions. The presence of the carboxyl groups after hydrolysis provide the reactive points for subsequent modifications such as cross-linking.

关 键 词：聚对苯撑 共聚 侧链酯基 水解 

分 类 号：O632.7[理学—高分子化学]