氰酸酯／双马来酰亚胺树脂的增容改性研究

Compatible modification of cyanate ester/bismaleimide blends

采用增容改性的思路，在共混树脂中加入小分子增容剂，通过减弱单体分子间结晶作用力的方法，改善双酚A型氰酸酯，4，4′-双马来酰亚胺基二苯甲烷（BADCy／BDM）共混体系的熔、溶工艺特性，得到了低熔点、能溶于丙酮等溶剂的改性树脂。随着BDM含量的变化，改性树脂在丙酮中的溶解性降低，熔点呈“V”字型变化，在n（BADCy）：n（BDM）=1：1时，出现最低溶点（45℃）。未固化树脂在较宽的温度范围内具有良好的稳定性，为树脂固化提供了较宽的工艺窗口。固化树脂在BDM含量为30％和40％时，呈现出两个玻璃化转变温度，而在50％含量时，只出现一个玻璃化转变温度。增容改性树脂的弯曲强度和冲击强度均高于纯氰酸酯树脂，且在BDM含量40％时出现最大值。

A compatible modification method has developed by adding a low molecular organic compound into the bisphenol A dicyanate ester/4,4＇-diphenylmethane-bismaleimide （BADCy/BDM） blend system aim to improve the process parameters by reducing the interaction force existed between monomer molecules. Thus achieved modified resins having low melting point and feasible dissolve in acetone. Solubility of modified resin in acetone reduced while increase BDM content, and melting point varying in a ＂V＂ style. A eutectic melting point of 45℃ resulted for the equal mol ratio blend. The modified resin has good stability in broad temperature range provided a moderate process window. Two glass transition temperatures have been seen in the 30% and 40% BDM contents blends （weight percent） and only one Tg in 50% blend. The cured resins have superior flexure strength and impact strength compared with BADCy and the maximum value achieved in 40% blend.