SYNTHESIS OF SIDE-CHAIN LIQUID-CRYSTAL POLYMERS BY LIVING RING-OPENING METATHESIS POLYMERIZATION .1. INFLUENCE OF MOLECULAR-WEIGHT, POLYDISPERSITY, AND FLEXIBLE SPACER LENGTH (N = 2-8) ON THE THERMOTROPIC BEHAVIOR OF THE RESULTING POLYMERS

被引：85

作者：

KOMIYA, Z ^{[1
]}

PUGH, C ^{[1
]}

SCHROCK, RR ^{[1
]}

机构：

[1] MIT,DEPT CHEM,6-331,CAMBRIDGE,MA 02139

来源：

MACROMOLECULES | 1992年 / 25卷 / 14期

关键词：

D O I：

10.1021/ma00040a001

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The living ring-opening metathesis polymerization of 5-{[n-[(4'-methoxy-4-biphenylyl)oxy]-alkyl]carbonyl}bicyclo[2.2.1]hept-2-ene (1-n, n = 2-8) by Mo(CH-t-Bu)(NAr)(0-t-BU)2 (Ar = 2,6-C6H3-i-Pr2) is described. Polymers with degrees of polymerization from 5 to 100 and narrow molecular weight distributions (M(w)/M(n) = 1.05-1.24) were obtained in high yield. All polymers exhibit an enantiotropic nematic mesophase. Glass transition and isotropization temperatures increase with increasing molecular weight and become independent at approximately 30-50 repeat units. The change in enthalpy of isotropization is relatively independent of molecular weight. Using polymer blends, it was shown that polydispersity has no effect on either the transition temperatures or the temperature range of isotropization. Isotropization alternates in an odd-even manner up to spacer lengths of n = 6 and then levels off.

引用

页码：3609 / 3616

页数：8

共 49 条

[1] POLYMERIZATION OF FUNCTIONALIZED NORBORNENES EMPLOYING MO(CH-T-BU)(NAR)(O-T-BU)2 AS THE INITIATOR [J].