Zirconium tungstate/bismaleimide composite

Abstract

The residual stress that arises from processing and the mismatch of coefficient of the thermal expansion (CTE) between polymer and carbon fiber (or metal) could cause a crack initiation and de-lamination in the aircraft structural applications. In this study, bismaleimide composites with zirconium tungstate (−8.8 ppm/K) were successfully fabricated. A synergetic effect led to a significant improvement of the thermal stability of the composites due to the formation of the integrated structure in the zirconium tungstate (ZrW2O8)/Matrimid 5292 (Huntsman, the Woodlands, TX) composite at high temperature, which prevented and/or slowed the escape of the thermal decomposition by-products. The addition of zirconium tungstate into the Matrimid 5292 could also increase the storage modulus while keeping the glass transition temperature unchanged. The CTE of a 20 vol.% ZrW2O8/Matrimid 5292composite material can be reduced by 40% compared with that of the pure Matrimid 5292. The extent of reduction in the CTE is much greater than predicted from the rule of mixture. Micromechanical modeling shows that the Christensen model and the Schapery upper limit model gave a good prediction of CTEs for ZrW2O8/Matrimid 5292 composite. Published 2011. This article is a US Government work and is in the public domain in the USA.