PURPOSE: To provide a novel thermoplastic polymer consisting of a vinyl copolymer containing cyclic glutarimide structural unit in the main chain, having high depolymerization activation free energy and excellent heat decomposition resistance and transparency, and producible easily.
CONSTITUTION: The objective polymer which is a vinyl copolymer containing the cyclic structural unit of formula (R1 and R2 are H or 1W4C alkyl, preferably both R1 and R2 are methyl; R3 is H, 1W6C alkyl, cycloalkyl or phenyl) having a depolymerization activation energy of ≥56.5kcal/mol can be produced by heat- treating a copolymer of e.g. methacrylamide and methyl methacrylate in an inert gas atmosphere to effect the intersegment condensation cyclization reaction in the molecule. The intrinsic viscosity of the polymer is preferably 0.01W2dl/g.
EFFECT: It has high solubility in solvents, and can be utilized effectively in the industrial field.
SASAKI ISAO
NISHIDA KOUJI
