Structure-property relationships in PMR-type polyimide resins: 4. Investigation of materials derived from diamino(diaryl)methanes

Abstract

Polyimide oligomers (prepolymers) and resins of the PMR-15 type have been prepared from 5-norbornene-2,3-dicarboxylic half acid ester (NE), 3,3′,4,4′-benzophenonetetracarboxylic diester (BTDE) and a series of diamines including, and related to, 3,3′-diaminobenzophenone, viz. 3,3′-diaminobenzhydrol, 3-[( m, m′-diamino)benzhydryloxy]propyne (MDA-OMA) and 3,3′-diaminodiphenyl-α,α′-difluoromethane (FMDA). The PMR synthetic pathway (monomers→prepolymer→resin) has been assessed by dynamic mechanical thermal analysis. The T g values for resins incorporating BTDE are significantly lowered compared to that for PMR-15 itself. The fluorine-containing PMR-15 type of resin (from FMDA) is of higher thermal stability than PMR-15 itself.