聚苯基缩水甘油醚中的间规立构组分(s-PPGE)的研究

STUDIES ON THE SYNDIOTACTIC FRACTION OF POLY (PHENYL GLYCIDYL ETHER) (s-PPGE)

对间规PPGE的合成、性质和催化剂的结构进行了研究 .研究发现 ,间规PPGE的获得与Bu2 SnO Bu3 PO4缩合物催化剂的结构有关 ,经过两次缩合得到的催化剂Sn P80 0 0中存在全同立构和间规立构两种活性中心 .提高聚合温度可提高PPGE的全同立构规整度 .与全同PPGE不同 ,间规PPGE可溶于氯仿、甲苯等溶剂 ,结晶能力低于全同PPGE ;其热诱导结晶速度很慢 ,但它在合适溶剂如丙酮的诱导下可以较快地结晶 .

The preparation of syndiotactic polymers through ring\|opening polymerization of a chiral monomer bearing one asymmetric center in the ring was not found in literature.This paper presents the synthesis and properties of syndiotactic poly(phenyl glycidyl ether)(PPGE).Phenyl glycidyl ether was polymerized under the effect of Bu 2SnO\|Bu 3PO 4 condensates (Sn P).The tacticity of the obtained PPGE was dependent upon the structure of the catalyst.The Sn\|P condensate obtained through a condensation reaction at 220～260℃ for 30～60 min,and then at 150～220℃ for 1h had two kinds of stereoselective center.Syndiotactic\|rich PPGE fractions ( s \|PPGE) were separated from the polymerization products obtained using Sn\|P 8000,a condensate prepared by the two\|step condensation,as catalyst.The yield of the s \|PPGE fractions reduced as the polymerization temperature enhanced,indicating the activation energy for the syndiotactic center in the catalyst is lower than that for the isotactic center.Compared to the insoluble character of isotactic PPGE ( i PPGE) in any known solvents, s \|PPGE can be dissolved in solvents such as chloroform and toluene.The crystallization ability of s PPGE is lower than that of i \|PPGE.The thermal induced crystallization of s PPGE is very slow.However in the presence of an appropriate solvent such as acetone,it may crystallize quickly.