Biodegradable polymer composition and its application

The present invention is calculated in parts by weight， i) 58 to 80 parts by weight of an aliphatic-aromatic copolyester; ii) 20 to 32 parts by weight starch; And iii) 0 to 10 parts by weight of a treating agent; Disclosed is a biodegradable polyester composition comprising as a component. The present invention， through the study， the aromatic carboxylic acid content of 44 mol% to 48 mol% of the total amount of diacid as an aliphatic-aromatic copolyester as a matrix resin， the width of the aliphatic-aromatic copolyester crystallization peak D Is 5 to 16 ， while using a starch having a particle size D (50) of 2 μm to 12 μm as another phase， and by adding a specific amount of the treatment agent， the polyester composition obtained is excellent in the longitudinal and transverse directions In addition to having tear strength， the polyester composition was found to be satisfactory as industrial compost， with a biodegradation rate of 90% or more during a 12 week biodegradation test. Disclosed is a biodegradable polyester composition， comprising the following components in percentage by weight: i) 58-80 parts of aliphatic-aromatic copolyester; ii) 20-32 parts of starch; and iii) 0-10 parts of processing assistant agents. According to the present invention， it can be unexpectedly found during studies that the aliphatic-aromatic copolyester in which the aromatic carboxylic acid is 44 mol%-48 mol% as the total amount of diacid is used as a base resin， the crystalline peak width D of the aliphatic-aromatic copolyester is 5??C-6??C， and the starch having the particle size D(50) of 2 ??m-12 ??m is used as another phase; meanwhile， a processing assistant agent having the particular content is added， the polyester composition obtained by preparing has excellent transverse and longitudinal tear strength， meets industrial compost， and has more than 90% of biodegradation rate in a 12-week degradation test process. Disclosed is a biodegradable polyester composition， comprising the following components in percentage by weight: i) 58-80 parts of aliphatic-aromatic copolyester; ii) 20-32 parts of starch; and iii) 0-10 parts of processing assistant agents. According to the present invention， it can be unexpectedly found during studies that the aliphatic-aromatic copolyester in which the aromatic carboxylic acid is 44 mol%-48 mol% as the total amount of diacid is used as a base resin， the crystalline peak width D of the aliphatic-aromatic copolyester is 5??C-6??C， and the starch having the particle size D(50) of 2 ??m-12 ??m is used as another phase; meanwhile， a processing assistant agent having the particular content is added， the polyester composition obtained by preparing has excellent transverse and longitudinal tear strength， meets industrial compost， and has more than 90% of biodegradation rate in a 12-week degradation test process.