Preparation of high performance foams with excellent dielectric property based on toughened bismaleimide resin

In order to meet the increasing demands on high performance foams with excellent dielectric property by modern industries, a new type of high performance foams based on diallyl bisphenol A modified bismaleimide (BDM/BA) resin is first developed in this paper. The effects of processing parameters such as prepolymerization time and temperature, foaming temperature and time as well as the content of blowing agent on the properties and morphology of resultant foams are intensively investigated from the view of processing–property–morphology relationship. Results show that compared with BDM/BA resin, the optimum condition of prepolymerization is 140°C for 60 min, and that of foaming is 160°C for 35 min. Foams based on BDM/BA resin with 9 wt% AC135 have uniform cell distribution, and greatly improved dielectric property. Copyright © 2010 John Wiley & Sons, Ltd.