Date of Publication:2005-01-01

Journal:合成树脂及塑料

Volume:22

Issue:2

Page Number:38-41

ISSN No.:1002-1396

Abstract:Polylactides (PLA) was synthesized by two-step process; firstly, high purity lactide monomer had been prepared from D,L-lactic acid and then, a series of lactide homopolymers having different molecular mass had been synthesized with stannous octoate as initiator and lauryl alcohol as chain transfer agent (i.e. regulator for relative molecular mass) via ring-opening polymerization under high vacuum condition. An orthogonal table of experiment was designed, in which dosage of initiator, amount of chain transfer agent, polymerization temperature and reaction time were taken as elements. The reaction conditions for PLA with relatively high molecular mass were determined as follows: mass fraction of stannous octoate 0.1%, mass fraction of lauryl alcohol 0.04%, polymerization temperature 130°C and polymerization time 10 hours. The effect of concentration of chain transfer agent on the relative molecular mass of PLA was studied; a quantitative relation between relative molecular mass of PLA and amount of chain transfer agent was established. The structure and proper ties of PLA were characterized by gel permeation chromatography, Fourier transform infrared spectroscopy and hydrogen spectrum of nuclear magnetic resonance.

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