▎ 摘　　要

NOVELTY - A chain extender comprises 20-35 parts mass isocyanate, 60-75 parts mass organic compound with hydroxyl group, 0.05-0.1 part mass catalyst, 10-15 parts mass layered graphene carrier, 0.2-0.5 part mass accelerator, and 0.5-1 part mass zinc stearate. USE - The chain extender is useful for degradable plastic including photodegradable plastic, biodegradable plastic, light/oxidation/biodegradable plastic, carbon dioxide-based biodegradable plastic and thermoplastic starch resin degradable plastic. ADVANTAGE - The chain extender uses layered graphene, which is a planar structure, and contains large number of active groups on surface. The graphene has excellent dispersibility, so that isocyanate chain extender is well dispersed in the degradable polyester, avoids the partial excess of isocyanate, and solves the problem of gel or crystal point of the product. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the chain extender, which involves: (1) mixing isocyanate, organic compound with hydroxyl group and catalyst to carry out polycondensation to obtain a polycondensate; (2) mixing the polycondensate with layered graphene carrier, adding accelerator, stirring under high temperature and high pressure to ensure that the carrier and accelerator fully react, leaving still, and cooling to obtain a polymer; and (3) mixing the polymer with zinc stearate at room temperature and high speed.