Addition polyimides. IV. Effect of structure on thermal characteristics

Chain extension reaction of bis(m-maleimido phenyl) methyl phosphine oxide (BP) with 4,4′-diaminodiphenylmethane (BP–M), 4,4′-diaminodiphenyl ether (BP–E), 3,3′- and 4,4′-diaminodiphenyl sulfone (BP–DDS_m and (BP-DDS_m respectively), tris (m-aminophenyl) phosphine oxide (BP–TAP), and 9,9-bis(p-aminophenyl) fluorene (BP–BAF) was carried out by refluxing 1:0.3 molar solution of BP:diamine. The melting temperature and exothermic peak associated with curing of BP decreased by such chain extension. The thermogravimetric analysis indicated more than 60% residual weight at 800°C in nitrogen atmosphere in BP–DDS_m, BP–DDS_p, and BP–TAP resins. These resins can be processed at low temperature and can be used for fabrication of composites with improved properties.