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Tris‐benzil crosslinked polyphenylquinoxalines
Author(s) -
Rafter R. T.,
Harrison E. S.
Publication year - 1976
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760160508
Subject(s) - comonomer , materials science , benzil , composite material , flexural strength , graphite , polymer , polymer chemistry , void (composites) , solvent , composite number , copolymer , organic chemistry , chemistry , catalysis
Abstract Polyphenylquinoxalines (PPQ) were crosslinked with a tris‐benzil comonomer, to alleviate the inherenthigh temperature thermoplasticity, and evaluated as matrices in graphite reinforced composites. The room temperature flexural strength/modulus of Modmor IJ laminates were as high as 245,000 psi/16,6 × 10 6 psi. Essentially 100 percent retention of ambient mechanical properties was obtained at 371°C using a PPQ matrix from the fully‐crosslinked polymer prepared from 4,4′‐bis(4″‐oxybenzilyl) benzil (BOBB) and 3,3′‐diaminQbenzrdine. The degree of high temperature thermoplasticity in the composite was found to be more closely related to the final postcure temperature than to the BOBB crosslink density. The thermoplasticity essentially disappeared when the BOBB comonomer‐PPQ laminates were postcured at 482–510°C in nitrogen. Substitution of DMAC for the commonly used m ‐cresol solvent system allowed facile preparation of prepreg to fabricate low‐void laminates and NOL rings.