| abstract |
(57) [Summary] [Structure] Having a weight average molecular weight of 30,000 or more, And a biodegradable poly (lactic acid) having a star-shaped molecular structure in which a large number of polymer chains are radially arranged and bonded to a polyhydroxyl compound, and a polyhydroxyl compound having at least 4 hydroxyl groups is mixed with lactic acid Heating the obtained mixture under reduced pressure in the absence of a catalyst to remove water to obtain low molecular weight poly (lactic acid); and reducing the poly (lactic acid) under reduced pressure in the presence of a catalyst. A method for producing the biodegradable poly (lactic acid), which comprises the step of heating the lower part and subjecting it directly to polycondensation. [Effects] The above poly (lactic acid) exhibits excellent tensile strength due to its high molecular weight, and is widely used as a versatile biodegradable material, a base for sustained release of pharmaceutical or agricultural chemical delivery, and an agricultural film. You can |