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Polystyrene and poly(phenylene methylene) of relatively low molar mass (2000–3000) have been converted through nitro and amino derivatives into maleimido-functionalized oligomers. The latter have been characterized spectroscopically and oligomers and cured resins derived therefrom studied by thermal gravimetric analysis. Both polystyrene and poly(phenylene methylene) show greater thermal and thermo-oxidative stability than the corresponding maleimido derivatives. This trend is also observed when comparing poly(phenylene methylene) with the crosslinked resin derived from maleimidopoly(phenylene methylene). The opposite trend is observed for polystyrene and the cured resin derived from maleimidopolystyrene.

Dynamic mechanical thermal analysis (d.m.t.a.) profiles have been recorded for interaction of m-tolualdehyde azine and 3,5-dimethylpyridine N-oxide with the bismaleimide (BMI) derived from 3,3-diaminobenzophenone. Additional chemical events for each system are recognized at temperatures below the conventional BMI curing region. Resins prepared from the BMI/azine and BMIN-oxide systems have lower thermal stability than the neat resin but differences are moderate at low additive concentrations.

Novel aromatic polyimides prepared via the polymerization of monomeric reactants (PMR) approach and incorporating anthraquinone diamines in the main chain have been characterized. Imidization and crosslinking reaction profiles have been delineated by d.m.t.a. and the high-temperature mechanical and thermal properties of the thermoset resins examined. Elevated glass transition temperatures (> 300°C) are apparent in some resins while impairment of mechanical integrity is not evident below 450°C. All resins show good thermal and thermo-oxidative stability.