SynopsisMichael additions of the secondary diamines N,W-dimethyl-l,6-hexanediamine (14) or piperazine to the electrophilic carbon-carbon double bonds of N,N'-bismaleimido-4,4'-diphenylmethane (2) or N , N -bismaleimido-l,8-octane (4) afford four unusual, high-molecular-weight (qinh = 0.49-2.16 dL/g) polyimides (10-13). The most interesting of these, polymer 12 (the product of 4 and 14), is a tough elastomeric resin with a glass transition temperature (T,) near 0°C; in contrast, 10,11, and 13 exhibit Tg > 86°C. Freshly prepared 12 is soluble and thermoplastic (12 is readily compression molded a t llO"C), but the bulk polymer crosslinks slowly under ambient laboratory conditions and eventually (48 days) becomes insoluble, while 10, 11, and 13 remain soluble indefinitely. Along with further comparisons of the properties of 10-13, details of the synthesis and characterization of these new polyimides are described. Also discussed are reactions of bismaleimide 2 with 1,6-diaminohexane, which unlike the formation of linear 10-13, generate crosslinked, insoluble products.

Various alkanedithiols [HSRSH; R = (CH2)3–6 orCH2CH2OCH2CH2] add to the carbon‐carbon double bonds of N,N′‐bismaleimido‐1,8‐octane (1) at room temperature in m‐cresol that contains triethylamine as a catalyst to produce the corresponding polyimidosulfides (3) in yields of 75–86% and with inherent viscosities (ηinh) of 0.30–1.05 dL/g. In general (3) are amorphous, elastomeric materials that undergo glass transitions (Tg) within the range of 6.5–13°C but product (3a) [R = (CH2)6] is a tough, leatherlike polymer that exhibits Tg = 35°C and a melting transition at 77°C. X‐ray analysis indicates that (3a) is ca. 37% crystalline. In addition to further details of the synthesis and properties of polyimidosulfides (3), comparisons are made between crystalline (3a) and a structurally analogous but morphologically dissimilar, elastomeric polyaspartimide synthesized earlier from (1) and N,N′‐dimethyl‐1,6‐hexanediamine.

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