SYNTHESIS, THERMAL-PROPERTIES, AND GAS-PERMEABILITY OF POLY(N-N-ALKYLMALEIMIDE)S

Radical polymerization of N-n-alkylmaleimides (nRMI) with various n-alkyl groups (n = 4-18) was carried out in the presence of 2,2'-azobisisobutyronitrile in benzene at 60-degrees-C. The high molecular weight polymer (MBAR(n) > 10(5)) was obtained in a high yield from all nRMIs. The resulting poly(nRMI) were soluble in organic solvents such as benzene, chloroform, and THF, and a thin and tough film was obtained from the solution. It was confirmed that poly(nRMI) showed excellent thermal-stability, i.e., they had a high glass transition temperature and decomposition temperatures. The side-chain crystallization was investigated by differential scanning calorimetry. From the measurement of permeation of oxygen and nitrogen through poly(nRMI), it was revealed that these polymers had a high permeability coefficient of 10(-8)-10(-9) cm3 (STP)cm cm-2 s-1 cm Hg-1, which depended intensively on the N-substituents.