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Biodegradable Polymers, 9. Technologically Relevant Aspects of Kinetics and Mechanism of Ring‐Opening Polymerization of L , L ‐Dilactide
Author(s) -
Rafler Gerald,
Lang Jacqueline,
Jobmann Monika,
Bechthold Inna
Publication year - 2001
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/1439-2054(20011201)286:12<761::aid-mame761>3.0.co;2-e
Subject(s) - polymerization , materials science , depolymerization , monomer , polymer , polyester , polymer chemistry , kinetics , bulk polymerization , ring opening polymerization , chain transfer , catalysis , chemical engineering , condensation polymer , chain growth polymerization , chemistry , organic chemistry , radical polymerization , composite material , physics , quantum mechanics , engineering
Poly( L ‐lactide) is manufactured by a cascade process comprising the fermentation of glucose substrate, oligomerization of L ‐lactic acid, cyclization depolymerization to L , L ‐dilactide and ring‐opening polymerization of the cyclic diester. The process development requires detailed knowledge of kinetics, thermodynamics and reaction mechanism in all process stages. This paper aims to show the influence of micro‐ and macrokinetic factors on the course of the ring‐opening polymerization and the molecular parameters of the formed polyester. Monomer conversion and molecular weight of the polyester are determined by chemically active process parameters, like kind and concentration of catalyst and initiator, respectively, reaction temperature or presence of cocatalysts as well as by the intensity of mixing of the polymerizing melt. The highest polymerization rate is observed in presence of tin octoate, but this catalyst leads to a fast degradation of the formed polymer.