酚醛树脂固化动力学研究

采用DSC方法探讨了酚醛物质的量比(F/P)为1.3、1.5、1.8的酚醛树脂的固化反应过程。在50~300℃温度范围内以不同升温速率(5、10、15、20℃/min)进行动态固化行为分析。运用Kissinger和Ozawa法进行了动力学研究,得到其固化反应活化能。结果表明:两种方法计算得到活化能的大小顺序是一致的。高物质的量比酚醛树脂在固化过程中具有的活化能比低物质的量比酚醛树脂的要低,这就意味着高物质的量比酚醛树脂固化时需要较少热量。因此,酚醛树脂的F/P物质的量比越高,固化反应的活化能就越低。随升温速率提高,该种树脂的起始固化温度Ti,峰顶固化温度Tp,终了固化温度Tf都有提高,同时固化时间tc缩短。

Study on curing kinetics for phenolic resins

Differential scanning calorimetry(DSC) was used to study the curing behavior of phenolic resins with different formaldehyde/phenol,e g.F/P was 1.3,1.5,1.8 respectively.The kenetic analysis was performed by means of Kissinger,-ln(β/Tp~2)=-ln(AR/Ea)+(1/Tp)(Ea/R),and Ozawa method,ln β=ln A-E/RTp,at heating rates of 5,10,15 and 20 ℃/min between 50～300 ℃.DSC analysis showed that the seqence of activation energy colculated by Kissinger was consistent with that by Ozawa and the resins with high molar ratio of F/P exhibited a lower activation energy than the resins with low molar ratio of F/P in the curing process,that was less heat was needed to cure the high molar ratio F/P resins.With increasing heating rate the initial curing temperafure T_i,peak curing temperature T_p and final curing temperature T_f were all increased but the curing time t_c was shorter.