酚酞型聚芳醚砜(Ⅶ):K_2C0_3存在下PP/DCDPS体系聚合反应机理的研究

PHENOLPHTHALEIN POLYARYL ETHER SULFONES (VII): A STUDY ON THE POLYCONDENSATION MECHANISM OF PP/DCDPS VIA A POTASSIUM CARBONATE PROCESS

利用^(13)C-NMR方法研究了弱碱K_2CO_3存在下酚酞成盐反应及其与活性双卤砜亲核缩聚反应过程中的结构特征。对一系列碱性条件下酚酞(PP)与4,4'-二氯二苯砜(DCDPS)的缩聚反应的研究表明任何影响内酯结构酚酞盐生成的因素都会严重阻碍聚合反应的进行。对模型化合物存在下K_2CO_3在极性非质子溶剂中的溶解/解离行为的研究结果表明酚酞类Card。双酚与固体K_2CO_3之间可能存在着一种特殊的络合作用。基于我们系列研究结果,本文中总结提出了弱碱K_2CO_3存在下酚酞的反应机理。

Several experiments were desighned to reveeal the reaction mechanism of phenolphthalein during its condensating with DCDPS in presence of potassium carbonate. The results show that the special stereo-structure derived from phenolphthalein's cardo group and its phenol rings makes it possible to form an intermediate complex between the solid potassium carbonate and phenolphthalein, which was proved to benifie to the solvation of solid potassium carbonate, the formation of the phenoxide, and to the further nucleophilic substitution reaction. It is also confirmed that the phenoxides' structures formed in potassium carbonate system are different from that formed in potassium hydroxide system. Based on our series experimental results, a new reaction mechnism was proposed.