POLYMERIZATION MECHANISM OF N-VINYLCARBAZOLE WITH CHIRALLY ORGANIC SALT AS CATALYST

The polymerization mechanism is described by the conductance changewith the time during the polymerization. The mechanism can be explained by the equi-librium feature (i.e. main ion-pairs) between the free ions and the ion-pairs dissociated bythe organic salt (-) Sp~/(*~+) (+) CSA~(*~-) (An asterisk represents the chirality) and the schemeof the polymerization process is described mainly by the charge transfer complexes havingchiral induction power.     

SYNTHESIS OF OPTICALLY ACTIVE POLY (N-VINYLCARBAZOLE)S

The organic salts as initiators [A~+B~-:Ph_3C~+ClO_4~-, Ph_3C~+SbCl_6~-, (-)Sp~+ClO_4~- and(-)(Sp)_2~(+3)(ClO_4)_3] and catalysts [A~+B~-:(+)CSA, A~+B~-:Ph_3C~+(+)CSA~- and(-)Sp~+(+)CSA] are prepared and characterized by specific rotation. The asymme-trically stereoselective induction of the initiators and catalysts in the polymerization ofN-vinylcarbazole is in an order of A~+B~->A~+B~->A~+B~-. The specific rotations ofobtained poly (N-vinylcarbazole ) (PVCZ) generally are in accordance with mentioned order.     

STRUCTURE AND PROPERTIES OF POLY (N-VINYLCARBAZOLE) OBTAINED VIA ASYMMETRICALLY STEREOSELECTIVE POLYMERIZATION

The structure and properties of poly(N-vinylcarbazole) (PVCZ) obtainedvia asymmetrically stereoselective polymerization have been studied by using ~1HNMRspectra, UV spectra, DSC analysis and GPC. The steric microstructure i.e. the contentof isotactic sequences was found to be increased by using AIBN to (-)Sp~+(+)CSA~- asthe initiators or catalysts and the mole extinction coefficient to be decreased. Bimodalmolecular weight distribution (MWD)s of the obtained PVCZs were caused by two propa-gating species of the free ions and the ion-pairs associated with the organic salts duringpolymerization.     

基于L-(+)-酒石酸二乙酯的光学活性聚酯的合成与表征

对基于Ｌ （＋） 酒石酸二乙酯和邻、间、对位苯二甲酰氯的光学活性聚酯进行了合成．这类聚酯的比旋光度与所采用的二酰氯有关,依次为对苯＞间苯＞邻苯．通过模型化合物、最小能量优化及圆二色谱等分析表征阐明了这类聚酯不同的结构形态特征．