环氧树脂与树状大分子PAMAM的等温固化反应动力学研究

STUDY ON CURING KINETICS OF EPOXY RESIN WITH DENDRITIC POLYMER PAMAM BY ISOTHERMAL DSC

  • 摘要: 以等温DSC法研究了在60、65、70和75℃下,环氧树脂E-44和树状大分子聚酰胺-胺(PAMAM)体系的固化反应动力学过程,结果表明该固化反应符合自催化反应模型. 通过Kamal方程计算出各固化动力学参数,其中反应总级数m+n在2.13~2.21之间,反应活化能E1和E2分别为52.65 、65.47 kJ/mol. 由于固化后期受扩散控制,且温度越低扩散控制越显著,引入扩散因子f(α)对Kamal模型进行修正,所得的修正模型能更好地描述固化全过程.

     

    Abstract: The curing reaction kinetics of epoxy resin and dendritic polymer PAMAM was investigated under isothermal curing condition using Differential Scanning Calorimeter (DSC) at 60、65、70 and 75℃. It was found that the curing reaction of the PAMAM and epoxy resin system have autocatalyzed controlled characteristics. All parameters of isothermal curing kinetics were determined by an autocatalytic mechanism proposed by Kamal eqution. The overall reaction order m+n was between 2.13 and 2.21, and the apparent activation energies of E1 and E2 were 52.65 kJ/mol and 65.47 kJ/mol. Since, in the later curing stage, the curing reaction was affected by the diffusion-controlled, and the effect of the diffusion was much evident at a lower temperature, a diffusion factor f(α) was introduced into the Kamal model. The revised cure kinetic model agreed better with the whole curing process, especially in the later curing stage controlled by diffusion.

     

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