PREPARATION OF ALTERNATING COPOLYMERS FROM THE RING-OPENING METATHESIS POLYMERIZATION OF 3-METHYLCYCLOBUTENE AND 3,3-DIMETHYLCYCLOBUTENE

被引:72
作者
WU, Z [1 ]
GRUBBS, RH [1 ]
机构
[1] CALTECH,ARNOLD & MABEL BECKMAN LABS CHEM SYNTHESIS,PASADENA,CA 91125
关键词
D O I
10.1021/ma00114a002
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Monomers 3-methylcyclobutene (1) and 3,3-dimethylcyclobutene (2) can be polymerized by well-defined alkylidene complexes of the type M(CHC(CH3)(3))(NAr)(OC(CH3)(n)(CF3)(3-n))(2) (where Ar = 2,6-diisopropylphenyl; M = Mo or W; n = 2 or 3) to give polymers, which upon hydrogenation are equivalent to alternating copolymers of poly(ethylene-alt-propylene) and poly(ethylene-alt-isobutylene), respectively. Monomer 2 can be polymerized in a highly regioselective fashion to give polymers with exclusively trans and head-to-tail configuration. The high regioselectivity of the polymerization is attributed to the steric directing effect of the bulky substituent on the 3-position of the cyclobutene as the monomer approaches the propagating alkylidenes. In the presence of PPhMe(2) narrowly dispersed poly(3-methylcyclobutene) can be obtained.
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页码:3502 / 3508
页数:7
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