| 摘要 |
PROBLEM TO BE SOLVED: To provide a preparation method for easily obtaining a polylactic acid block copolymer that forms a polylactic acid stereocomplex having a high molecular weight and a high melting point. SOLUTION: The polylactic acid block copolymer preparation method comprises (1) a first step of preparing each of poly(L-lactic acid) composed of an L-lactic acid unit and poly (D-lactic acid) composed of a D-lactic acid unit and each having weight average molecular weight of 9,000-65,000, (2) a second step of mixing poly (L-lactic acid) and poly (D-lactic acid) obtained at the first step, and (3) a third step of solid-state-polymerizing the mixture of poly (L-lactic acid) and poly (D-lactic acid) obtained at the second step at a temperature lower than its melting point and equal to or above 120°C. COPYRIGHT: (C)2009,JPO&INPIT
|
