【摘要】 采用差示扫描量热法(DSC)研究了聚氨酯预聚体改性双酚A型氰酸树脂的固化行为及工艺,通过动态热机械分析(DMA)、热重分析(TGA)、介电性能和冲击强度测试对其玻璃化转变温度(Tg)、耐热性、介电性能和韧性进行了研究。结果表明,聚氨酯预聚体的加入可以很好地提高氰酸酯的韧性,当预聚体加入量为20%(质量分数)时,改性氰酸酯树脂的冲击强度达到最大值15.3kJ/m2,比纯氰酸酯树脂提高了218%。改性氰酸酯树脂的T_g逐渐降低,预聚体加入量为氰酸酯质量的40%时,T_g降低为193℃,仍然具有较低的介电常数和介电损耗。更多还原

【Abstract】 The curing process and behavior of the polyurethane prepolymer modified bisphenol A cyanate ester resins were studied by differential scanning calorimeter(DSC).The glass-transition temperature(Tg),heat resistance,dielectric properties and toughness of modified cyanate ester resins were investigated by dynamic thermomechanical analysis(DMA),thermal gravimetric analyzer(TGA),dielectric test and impact strength.The results showed that polyurethane prepolymer could increase its toughness well.When polyurethane prepolymer addition is 20%(wt%),the impact strength of the modified cyanate ester reaches a maximum of 15.3kJ/m2,higher than that of pure cyanate ester resin.The T_g of modified cyanate ester generally decreases.When PU prepolymer is added in an amount of 40% by mass of cyanate ester resins,the Tgis 193 ℃.The dielectric constant and dielectric loss are still low.更多还原