CATIONIC POLYMERIZATION OF 1,3,5,7 TETRAMETHYLCYCLOTETRASILOXANE INITIATED BY TRIFLUOROMETHANESULFONIC ACID

被引：19

作者：

GUPTA, SP ^{[1
]}

MOREAU, M ^{[1
]}

MASURE, M ^{[1
]}

SIGWALT, P ^{[1
]}

机构：

[1] UNIV PARIS 06,CHIM MACROMOLEC LAB,URA 24,4 PL JUSSIEU,F-75252 PARIS 05,FRANCE

来源：

EUROPEAN POLYMER JOURNAL | 1993年 / 29卷 / 01期

关键词：

D O I：

10.1016/0014-3057(93)90266-I

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Polymerization of 1,3,5,7 tetramethylcyclotetrasiloxane (D4H) by trifluoromethanesulphonic acid in CH2Cl2 solution at 20-degrees has given high polymers (HP) with molecular weights > 10(5). For sufficiently high monomer concentrations (e.g. 1.9 mol . l-1), the HP yield may reach 60%. Small cycles are formed together with the high polymer by back-biting reactions as in the case of octamethylcyclotetrasiloxane (D4) but the polymerization rate is much higher than that of D4 and near that of D3. The kinetics are quite different and much simpler than those observed for the dimethylcyclosiloxanes: the reaction is still internally 1st order in monomer, but the apparent rate constants are 1st order in both acid and monomer concentrations. This effect may result from the much larger reactivities of silyltrifluoromethanesulphonates derived from this monomer.

引用

页码：15 / 22

页数：8

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