Abstract: The present invention discloses a biodegradable complex oxygen barrier film and its preparation method and application. The biodegradable complex oxygen barrier film disclosed by the present invention is constituted of at least two support layers and a barrier layer which is deposed between each two support layers. The support layer is selected from at least one of the following substances: polylactic acid, poly(butylene succinate), polycaprolactone, poly(adipate-butylene telephthalate), poly(?-hydroxybutyrate) and poly(?-hydroxybutyrate-valerate); the barrier layer which is deposed between the each two support layers is same or different, the barrier layer is selected from any one of the following: poly(propylene carbonate) and nano montmorillonite modified poly(propylene carbonate).

Abstract: The present invention relates to improvement of the brittleness and cold flowability of a carbon dioxide-propylene oxide copolymer (PPC). The invention provides a blend comprising 50 to 98 parts by weight of a PPC; 2 to 50 parts by weight of a poly(butylenes succinate) (PBS) or poly(butylene succinate/adipate) (PBSA); 1 part by weight of a maleic anhydride, and 0.5 to 3.0 parts by weight of SiO2 and a method for producing the same. Compared with the pure PPC, the elongation rate at break of the blend of the invention increases by 3 to 15 times while the tensile strength maintains at 30 MPa or more. The blend of the PPC and PBSA can keep its dimension stably at 70° C., while the blend of the PPC and PBSA can keep its dimension stably at 55° C. No viscous flow occurs at these temperatures.

Abstract: The invention relates to a polymeric end-capping reagent for carbon dioxide-epoxide copolymers and a method for producing the same. The polymeric end-capping reagents provided by the invention are maleic anhydride copolymers and maleic anhydride terpolymers. The polymeric end-capping reagent for carbon dioxide-propylene oxide copolymers of the invention is produced by a radical solution copolymerization method, and has a number average molecular weight of Mn=4-6×104, a distribution index of 1.5-3.0. By using the polymeric end-capping reagent provided by the invention, the disadvantages of the small molecular end-capping reagent like volatilization during melting and precipitation on the melt surface during cooling, can be effectively overcome, moreover, the initial thermal decomposition temperatures of the carbon dioxide-propylene oxide copolymers end-capped with the polymeric end-capping reagents increase by about 30° C.