| 摘要 |
<p>PURPOSE: A method for preparing a high molecular weight polycarbonate resin is provided, to maximize the increase of molecular weight of polycarbonate after solid state polymerization and to reduce remarkably the reaction time. CONSTITUTION: The method comprises the steps of melting and reacting a dialkyl(aryl) carbonate and an aromatic hydroxy compound by ester exchange reaction to prepare a noncrystalline polycarbonate prepolymer with low molecular weight which has a weight average molecular weight of 1,500-15,00 g/mol; condensation polymerizing the noncrystalline polycarbonate prepolymer with low molecular weight to prepare a noncrystalline polycarbonate with middle molecular weight which has a weight average molecular weight of 20,000-30,000 g/mol; preparing a crystalline polycarbonate from the noncrystalline polycarbonate with middle molecular weight by solvent-induced crystallization; and solid state polymerizing the crystalline polycarbonate to prepare a high molecular weight polycarbonate with a weight average molecular weight of 35,000-200,000 g/mol.</p> |
