Abstract: A biodegradable film is prepared from a composition that includes a copolyester obtained by extrusion reaction of a branched aliphatic-aromatic copolyester derived from monomer a, monomer b, monomer c and monomer d with an organic peroxide. The film can be completely degraded into small molecular products such as carbon dioxide, water and the like under natural or composting conditions. Moreover, the film can be prepared having a thickness of 4-50 ?m as required, and its mechanical properties can reach the same level as or even better than those of LDPE film.

Abstract: The present invention relates to a transparent copolyester, wherein the transparent copolyester comprises an aliphatic-aromatic copolyester segment A, a segment B having repeating units —O—CH(CH3)—C(O)—, and structural units C derived from polyisocyanate(s), wherein the weight ratio for the segment A, segment B and structural unit C is 100:(100-2000):(0.1-10) and wherein the weight-average molecular weight Mw of the transparent copolyester is from 50,000 to 1,000,000. The present invention further relates to a preparation method for a transparent copolyester, including polymerizing lactide, a hydroxyl-terminated aliphatic-aromatic copolyester and a polyisocyanate in the presence of a catalyst; wherein the weight ratio for the aliphatic-aromatic copolyester, lactide and polyisocyanate is 100:(100-2000):(0.1-10). The present invention further relates to a transparent copolyester prepared by said method and an article made from the transparent copolyester according to present invention.

Abstract: The present invention relates to a biodegradable composite and its preparation process, which composite is prepared by mixing feed stocks comprising a polylactic acid, an aliphatic-aromatic copolyester A, an aliphatic-aromatic copolyester B and an organic peroxide at a temperature between about 100 and about 200° C. The present invention also relates to a disposable article, which is prepared from said biodegradable composite.

Abstract: The present invention relates to a transparent copolyester, wherein the transparent copolyester comprises an aliphatic-aromatic copolyester segment A, a segment B having repeating units —O—CH(CH3)—C(O)—, and structural units C derived from polyisocyanate(s), wherein the weight ratio for the segment A, segment B and structural unit C is 100:(100-2000):(0.1-10) and wherein the weight-average molecular weight Mw of the transparent copolyester is from 50,000 to 1,000,000. The present invention further relates to a preparation method for a transparent copolyester, including polymerizing lactide, a hydroxyl-terminated aliphatic-aromatic copolyester and a polyisocyanate in the presence of a catalyst; wherein the weight ratio for the aliphatic-aromatic copolyester, lactide and polyisocyanate is 100:(100-2000):(0.1-10). The present invention further relates to a transparent copolyester prepared by said method and an article made from the transparent copolyester according to present invention.

Abstract: The present invention relates to a biodegradable composite and its preparation process, which composite is prepared by mixing feed stocks comprising a polylactic acid, an aliphatic-aromatic copolyester A, an aliphatic-aromatic copolyester B and an organic peroxide at a temperature between about 100 and about 200° C. The present invention also relates to a disposable article, which is prepared from said biodegradable composite.