Polymers of carbonic acid. XXVII. Macrocyclic polymerization of trimethylene carbonate

✍ Scribed by Hans R. Kricheldorf; Andrea Stricker; Martina Lossin

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 216 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990701)37:13<2179::aid-pola33>3.0.co;2-x

✦ Synopsis

2,2-Dibutyl-2-stanna-1,3-dioxepane (DSDOP) was used as cyclic initiator for the polymerization of trimethylene carbonate (TMC). The polymerizations were either conducted in concentrated chlorobenzene solution at 50 and 80°C or in bulk at 60 and 120°C. With monomer/initiator ratios Յ100 the conversion was complete within 2 h at 80°C and within 12 h at 50°C. Variation of the reaction time revealed that the rapid polymerization is followed by a relatively rapid (backbiting) degradation even at 80°C. The polymerizations in bulk at 60°C were somewhat slower than those at 80°C in solution, but the influence of degradation reactions was less pronounced. With optimized reaction time the number average molecular weight (M n ) roughly parallels the monomer/initiator ratio and M n 's up to 100,000 were obtained. In contrast to a classical living polymerization broader polydispersities (1.5-1.7) were found. In the case of 5,5-dimethyltrimethylene carbonate rapid degradation and chain transfer reactions prevented the formation of high molecular weight polymers.