| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polylactic acid block copolymer forming a polylactic acid stereocomplex having a high molecular weight and a high melting point. SOLUTION: The method for producing the polylactic acid block copolymer comprises a solid phase polymerization of a mixture obtained by mixing a poly-L-lactic acid with a poly-D-lactic acid, wherein at least either of the poly-L-lactic acid and the poly-D-lactic acid satisfies formula: (ΔHm-ΔHc)>20 (J/g), and has remaining crystals in mixing, wherein theΔHm is a crystal-melting enthalpy (J/g), theΔHc is a crystallization enthalpy (J/g) in temperature rising. The polylactic acid block copolymer with weight average molecular weight of 100,000 or more can be prepared by performing solid phase polymerization of the mixture obtained by mixing with shearing or pressing. COPYRIGHT: (C)2011,JPO&INPIT |
