文档介绍：周大鹏*联系人简介:周大鹏(1977年出生),男,博士,讲师,主要从事酚醛树脂及其复合材料方面的研究, E-mail: zdp9270@
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(嘉兴学院生物与化学工程学院,嘉兴 314001)
摘要:利用差示扫描量热(DSC)分析技术研究了不同邻对位比值(O/P值)的酚醛树脂的固化活化能及固化进程。采用Ozawa模型求解了不同O/P值酚醛树脂的固化活化能及固化动力学参数,结果表明,酚醛树脂的固化活化能随其O/P值的增加而降低,固化进程变得更加容易。固化反应过程中的Ozawa反应指数随着固化反应温度的升高而下降,并且随着树脂O/P值的增加,出现在更低的温度区间内。Ozawa反应速度常数在固化反应初期随温度的升高而增加,在反应后期则随着温度的升高而下降,并且随着树脂O/P值的增加,出现峰值对应的温度降低, 表明固化先后经历了微凝胶增长与扩散反应控制两个阶段,树脂O/P值的增加加快了微凝胶的增长进程。
关键词:酚醛树脂,邻对位比值,固化行为, 差示扫描量热法
中图分类号:
A study on curing properties of novolac-type phenolic resin with vary O/P ratios by differential scanning calorimetry
ZHOU Da-Peng
(Biochemistry and Chemical Engineer Department, JiaXing Institute, JiaXing 314001)
Abstract: The activation energy of curing reaction and the curing process of phenolic resins with varying O/P ratios were studied by a nonisothermal differential scanning calorimetry (DSC). The activation energy decreased with increasing the O/P ratio. It was also found that the Ozawa exponent values decreased with increasing reaction temperature, and the Ozawa exponent values presented in the lower temperature range with increasing the O/P ratio. The reaction rate constant was found to increase in initial curing stage while decrease in subsequent curing stage with increasing reaction temperature, suggesting a change in the reaction mechanism from microgel growth to diffusion controlled reaction, and the microgel growt