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Ring‐Opening Polymerization of L‐Lactide in Supercritical Chlorodifluoromethane
Author(s) -
Pack Ji Won,
Kim Soo Hyun,
Park Soo Young,
Lee Youn Woo,
Kim Young Ha
Publication year - 2005
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200550608
Subject(s) - polymerization , supercritical fluid , polymer chemistry , monomer , bulk polymerization , chemistry , ring opening polymerization , materials science , radical polymerization , organic chemistry , polymer
The ring‐opening polymerization of L ‐lactide initiated by 1‐dodecanol/stannous 2‐ethylhexanoate (DoOH/Sn(Oct) 2 ) was carried out in supercritical chlorodifluoromethane at various reaction times, pressures, and temperatures. The monomer conversion increased to ca 70 % on increasing the reaction time to 25 h. The molecular weight of the product also increased to ca 75,000 g/mol over the same period. Increasing the pressure resulted in an accelerated polymerization rate. The pressure‐induced increase in the rate of L ‐LA polymerization can be explained by the formation of chemical bonds in the transition state, which implies the production of a transition state with a lower partial molar volume than the reactants.