Reactions of diaminoalkanes with bismaleimides: Synthesis of some unusual polyimides

Abstract

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.

Chemistry and properties of addition polyimides

“…Bismaleimides and bisnucleophiles have been exploited in syntheses of a variety of linear polymers. Dithiols [57][58][59][60][61] and diamines [62][63][64][65] are the favoured bisnucleophiles because of their high basicity.…”

Cycloaddition approach to the curing of polyimides via precursor containing thiophene‐S,S‐dioxide

“…• C or below [5]. Moreover, the polymer produced through such cross-linking exhibits significantly deteriorated tensile strength [6,7],presumably because car-sulfur bonds are weaker than carbon-carbon bonds.…”

Gamma Ray Irradiation‐Initiated Copolymerization of a Binary Casting System Involving DPBMIn and Vinylpyrrolidone

“…In this way, the thus modified BMIs with extended chain exhibited improved solubility and lowered degree of crosslink after cure. [8][9][10][11] Making use of these improvements, easier processability coupled with desired mechanical strength could be expected. [12] .…”