中温固化氰酸酯树脂基体动态热机械分析研究

Dynamic Mechanical Analysis of the Cyanate Ester Resin Curing at Moderate Temperature

采用动态热机械分析法详细考察了中温(125℃)固化氰酸酯树脂基体的温度-模量谱,研究了连续温度变化情况下促进剂用量、固化温度、环氧树脂、多官能氰酸酯对树脂基体的模量、损耗、玻璃化转变温度等使用性能的影响。促进剂的加入有效地提高了CE树脂中温固化反应程度和固化物的Tg,加入量在1.5phr时,改性CE树脂的弹性模量在150℃处显现出GPa量级波动,但仍呈玻璃态特征,表观Tg达238℃。提高固化温度,可使DMA曲线上的弹性模量波动消失,180℃固化后的Tg与中温固化的表观Tg相近。采用E-51环氧改性CE树脂,会显著降低树脂的耐热性。E-51用量在10份,Tg在233.5℃,用量到20份以上时,CE树脂的Tg急剧降低。酚醛型氰酸酯CY-5能有效地提高树脂的Tg,用量在20份时,Tg可达289℃。

The temperature-modulus spectroscopy of cyanate ester （CE） resin curing at moderate temperature （125℃） are examined in detail by using dynamic mechanical thermal analysis method. The effects of accelerator dosage, curing temperature, epoxy resin and novolac type cyanate ester resin on the performances of the resin such as the modulus, loss tangent, glass transformation temperature （Tg） is studied in the case of temperature changing continuously. The accelerator can effectively improve the glass transformation temperature and reaction degree of CE resin at moderate temperature. With 1.5phr of accelerator, the elastic modulus of the modified CE resin shows fluctuation in a GPa degree at about 150℃. The characteristic of the elastic modulus indicates that the modified CE resin is in the glassy region and the apparent Tg is 238℃. Increasing the curing temperature can make the fluctuation on the elastic modulus curve of DMA disappear. The Tg of the CE resin after curing at 180℃ is similar to the apparent Tg of the CE resin curing at moderate temperature. Modification of the cyanate resin using the E-51 can significantly reduce the heat resistance of the resin. The apparent Tg of the CE resin modified with 10 portions of E-51 is 233.5℃ and drops dramatically with more than 20 portions of E-51. The novolae type cyanate CY-5 can effectively improve the resin Tg, which can reach 289℃ with the amount of 20 portions of CY-5.