Cyclopolymerization of 1,5-hexadiene catalyzed by various stereospecific metallocene compounds

✍ Scribed by Il Kim; Young Shu Shin; Jin Kook Lee; Mi-Sook Won

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 155 KB
• Volume: 38
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(20000501)38:9<1520::aid-pola15>3.0.co;2-5

✦ Synopsis

Cyclopolymerization of 1,5-hexadiene has been carried out at various temperatures in toluene by using three different stereospecific metallocene catalystsisospecific rac-(EBI)Zr(NMe 2 ) 2 [EBI: ethylenebis(1-indenyl), Cat 1], syndiospecific Me 2 C(Cp)(Flu)ZrMe 2 (Cp ϭ 1-cyclopentadienyl, Flu ϭ 1-fluorenyl, Cat 2), and aspecific Cp* 2 ZrMe 2 (Cp*: pentamethylcyclopentadienyl, Cat 3) compounds in the presence of Al(i-Bu) 3 and [Ph 3 C][B(C 6 F 5 ) 4 ]-in order to study the effect of polymerization temperature and catalyst stereospecificity on the property and microstructure of poly(methylene-1,3-cyclopentane) (PMCP). The activities of catalysts decrease in the following order: Cat 1 Ͼ Cat 2 Ͼ Cat 3. PMCPs produced by Cat 1 are not completely soluble in toluene, but those by Cat 2 and Cat 3 are soluble in toluene. trans-Diisotactic rich PMCPs are produced by Cat 1 and Cat 2, and cis-atactic PMCP by Cat 3. The cis/trans ratio of PMCP by Cat 1 and Cat 2 is relatively insensitive to the polymerization temperature, but that by Cat 3 is highly sensitive to the polymerization temperature. Melting temperatures of PMCP produced increase with the cis to trans ratio of rings.