聚醚酰亚胺对氰酸酯树脂/环氧树脂共混物的增韧作用

采用聚醚酰亚胺以提高双酚Ａ二氰酸酯／酚醛环氧树脂共混物的断裂韧性．实验结果表明，聚醚酰亚胺是氰酸酯／酚醛环氧树脂共混物的有效增韧剂，加入１５％的聚醚酰亚胺可使断裂韧性（ＫＩＣ）提高到１４５ＭＰａ·ｍ０．５，弯曲强度也有所提高．用扫描电子显微镜和动态粘弹谱研究了改性共混物的微观结构，具有双连续结构的共混物的耐溶剂性能大大下降，共混物的韧性和耐溶剂性主要与相行为有关， 固化工艺对含１０％聚醚酰亚胺的共混物的断裂韧性和形态没有明显的作用．

TOUGHENING OF POLYETHERIMIDE FOR CYANATE ESTER-EPOXY NOVOLAC RESIN BLENDS

Polyetherimide (PEI) was used to improve the brittleness of bisphenol A dicyanate- epoxy novolac resin blends. Inclusion of 15% PEI led to a 115% (mass fraction) increase of the fracture toughness (KIC) and slight increase in flexural strength with retention in flexural modulus compared to those of the unmodified cured blends. The microstrucures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. It was observed that the dichloromethane absorption of the modified resin with co-continuous phases structure increased significantly compared to the unmodified cured blends. The toughening improvement and the solvent resistance properties were correlated to the morphology of the modified blends. The cure schedules had no practical influence on the fracture toughness and morphologies of the blend incorporating 10% PEI modifier.