| 摘要 |
A high molecular weight thermoplastic copolymer of isobutylene and N-methyl maleimide is prepared by heating a mono-N-methylamide of a copolymer of isobutylene and maleic acid alone or together with its methylamine salt to a temperature of at least 150 DEG C. until substantially all the N-methylamide groups have been converted to N-methylimide groups. The mono-N-methylamide may be produced by treating a copolymer of isobutylene and maleic anhydride which is substantially insoluble in aliphatic and aromatic hydrocarbons with gaseous methylamine at a temperature below 150 DEG C.; such a copolymer may also be converted directly to the N-methyl maleimide copolymer by heating with methylamine at a temperature above 150 DEG C. |
