摘要:

2,3-Dimethylbutadiene-1,3 was polymerized to cis- and trans-1,4-poly(2,3-dimethylbutadiene) of high stereochemical purity with triisobutylaluminum/titanium tetrachloride initiator systems in n-hexane. With a mole ratio of Al/Ti of 2:1, pure cis isomer was obtained while an Al/Ti ratio of 1:2 in the initiator system produced the trans polymer of 1,4-poly(2,3-dimethylbutadiene) free from 1,2-isomers. For the cis-isomer a 0.5 mol% initiator to monomer ratio gives maximum molecular weight while a 1 mol% ratio gives maximum yield. For the trans-polymer the ratios are 1 and 2 mol%, respectively. The cis- and trans-polymers are high melting crystalline materials of melting points of 190°C and near 280°C, respectively. The glass transition temperatures were 2 and 12°C, respectively (onset of transition). The temperature of maximum rate of degradation was 380°C for both polymers.

ISSN:0022-233X    

DOI:10.1080/00222338108056834

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0022-233X    

DOI:10.1080/00222338108056823

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor