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.

Abstract: This invention relates to a catalyst for producing aliphatic polycarbonate, which is composed of a rare-earth coordination compound; an alkyl metal compound; a polyol; and a carbonate. The catalytic efficiency of the catalyst of the present invention is more than 8×104 g polymer/mol RE(RE is rare earth metal). The number average molecular weight of the polymer is higher than 30,000. The degree of carbon dioxide fixation is more than 42 wt % and the content of alternative sequence structure exceeds 97%.

Abstract: The present invention provides a method of preparation for a degradable, water and oil resistant protective membrane. In the said method, carbon dioxide copolymer is dissolved in a low toxic or non-toxic solvent to form a solution of 3-6 wt % concentration. After standing and filtration to remove metal oxide, the solution is used to coat the surface of the fabricated starch, paper pulp, or straw tableware by spraying or dipping. The residual solvent is removed by drying process and a degradable, water and oil resistant and transparent protective membrane is obtained. The thickness of the protective membrane is in the range of 10-20 micrometer. Metal ion content is lower than 1 ppm. No leakage and deformation of the tableware are observed after the tableware is immerged in water or edible oil for 4 hours at 80° C. The decoloration test by cold edible oil and ethanol is negative. Fungus test gives grade V.

Abstract: The present invention provides a method of preparation for a degradable, water and oil resistant protective membrane. In the said method, carbon dioxide copolymer is dissolved in a low toxic or non-toxic solvent to form a solution of 3-6 wt % concentration. After standing and filtration to remove metal oxide, the solution is used to coat the surface of the fabricated starch, paper pulp, or straw tableware by spraying or dipping. The residual solvent is removed by drying process and a degradable, water and oil resistant and transparent protective membrane is obtained. The thickness of the protective membrane is in the range of 10-20 micrometer. Metal ion content is lower than 1 ppm. No leakage and deformation of the tableware are observed after the tableware is immerged in water or edible oil for 4 hours at 80° C. The decoloration test by cold edible oil and ethanol is negative. Fungus test gives grade V.

Abstract: This invention relates to a catalyst for producing aliphatic polycarbonate, which is composed of a rare-earth coordination compound; an alkyl metal compound; a polyol; and a carbonate. The catalytic efficiency of the catalyst of the present invention is more than 8×104 g polymer/mol RE(RE is rare earth metal). The number average molecular weight of the polymer is higher than 30,000. The degree of carbon dioxide fixation is more than 42 wt % and the content of alternative sequence structure exceeds 97%.