| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing a biodegradable polyhydroxycarboxylic acid using a polymerization catalyst for polymerizing a hydroxycarboxylic acid such as lactic acid which scarcely affects environment even when dumped in the natural surroundings without recollecting after use, and further even if remaining in the product, does not cause a reaction with a drug or a harmful reaction in the living body. SOLUTION: This method of producing a high molecular weight polylactic acid or a lactic acid-sugar copolymer comprises adding phosphoric acid aqueous solution as a polymerization catalyst to L-lactic acid or a mixture of L-lactic acid and corn starch, and heating with agitation under reduced pressure or in the presence of an organic solvent such as D-limonene.
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