Preparation of high molecular weight poly(L-lactide-co-caprolactone)(85-15)

Abstract

Poly(L-lactide-co-caprolactone)(85-15)[P(LLA-CL)(85-15)] was synthesized from high purity L-lactide and ɛ-caprolactone using tin octoate as initiator by ring-opening polymerization, and characterized by infrared spectrum and ¹H-NMR spectrum. The synthesized P(LLA-CL)(85-15) is a random copolymer. The influences of polymerization temperature, polymerization time, dosage of initiator and polymerization pressure on the weight average molecular weight and the polydispersity index of P(LLA-CL)(85-15) were investigated. The optimum preparation conditions of P(LLA-CL) (85-15) are: the polymerization pressure is less than 0.5 Pa, the polymerization temperature is 130 °C, the n(M)/n(I) ratio is 8 000/1, and the polymerization time is 36 h. Under the condition, the weight-average molecular weight of prepared P(LLA-CL)(85-15) is 65.6×10⁴, and molecular weight distribution coefficient is 1.15.

Keywords

poly(L-lactide-co-caprolactone)(85-15) / copolymerization / high molecular weight / characterization

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