SYNTHESIS AND CHARACTERIZATION OF POLY(N-TERT-ALKYLMALEIMIDE)S .2. SYNTHESIS OF HIGH-MOLECULAR-WEIGHT POLYMALEIMIDE BY THERMOLYSIS OF POLY(N-TERT-ALKYLMALEIMIDE)S

N-tert-Butylmaleimide (tBMI), N-tert-amylmaleimide (tAMI) and N-tert-octylmaleimide (tOMI) were polymerized in the presence of a radical initiator to give high molecular weight polymers. The polymerization reactivity was found to depend on the bulkiness of the N-substituent. From thermogravimetric analysis of the polymers obtained, it was revealed that these polymers thermally decomposed via a two-step mechanism, i.e. elimination of olefins at the first step and decomposition of the resulting N-unsubstituted polymaleimide (poly(MI)) at the second step. The high molecular weight poly(MI) was isolated by thermolysis of poly(tBMI), poly(tAMI) and poly(tOMI) with elimination of isobutene, 2-methyl-1-butene and 2-methyl-2-butene, and 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene, respectively. It was also confirmed that the resulting poly(MI) had excellent thermal stability. © 1990 Springer-Verlag.