Chinese Academy of Sciences

Xiaojiang Zhao

Xianhong Wang

Fosong Wang

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&times;10 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%.

Catalyst for producing aliphatic polycarbonate and the preparation thereof

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&deg; C. The decoloration test by cold edible oil and ethanol is negative. Fungus test gives grade V.

Growing community of inventors

Changchu, China

Xiaojiang Zhao