PREPARATION METHOD OF POLYISOIMIDE

摘要

PURPOSE: A method for preparing polyisoimide is provided, to improve the mechanical properties, the heat stability, the electric insulation property, the flame retardancy and the chemical resistance by preventing the gelation generated during the cyclodehydration. CONSTITUTION: The method comprises the steps of polymerizing a dianhydride monomer and a diamine monomer; and preparing the polyisoimide from the polymer by the cyclodehydration in the presence of an end-capper selected from an acid chloride and a chloroalkylsilane at a low temperature of -30 to 10 deg.C. Preferably the acid chloride is selected from the group consisting of acetyl chloride, benzoic chloride, propanoic chloride and p-toluenesulfonyl chloride; and the chloroalkylsilane is chlorotrimethylsilane or chlorotriethylsilane. The amount of the end-capper is 0.01-0.2 mol based on 1 mol of the diamine monomer.