反应性微凝胶/尼龙6共混物的等温结晶动力学

Isothermal crystallization kinetics of reactive microgel/Nylon 6 blends

以熔融共混法制备了反应性微凝胶与尼龙6的共混物,采用差示扫描量热法研究了共混物的等温结晶动力学,通过Avrami方程、Arrhenius理论以及Hoffman理论描述了反应性微凝胶/尼龙6共混物的等温结晶过程.结果表明,Avrami方程能够很好的描述反应性微凝胶/尼龙6共混物的等温结晶过程,尼龙6和共混物的Avrami指数都在2~3之间,共混物的值稍有升高,结晶速率常数减小,说明反应性微凝胶的加入,改变了尼龙6的成核过程和球晶生长机理,降低了尼龙6的结晶速率;通过Arrhenius理论得到共混物的结晶活化能比纯尼龙6高,当反应性微凝胶的含量达到30%时,结晶活化能的值最大;通过Hoffman理论得到成核参数的值随反应性微凝胶含量的增大呈先增大再减小的趋势,反应性微凝胶的含量达到30%时,成核参数的值最大.

Blends composed of nylon 6 and reactive microgel were prepared by melting blending method. The isothermal crystallization kinetics of blends was investigated by differential scanning calorimetry and analyzed by the Avrami equation, Arrhenius and Hoffman theories. The result shows that the Avrami theory describes the isothermal crystallization kinetics of reactive microgel / nylon 6 blends very well. Avrami exponent of neat nylon 6 and blends is between 2 and 3. Avrami exponent of reactive microgel / nylon 6 blends is higher than that of nylon 6. The incorporation of reactive microgel decreases the crystallization rate constant, indicating that the reactive microgel can reduce the overall crystallization rate and change the nucleation process of nylon 6. The crystallization activation energy of the reactive microgel / nylon 6 blends is higher than that of nylon6 and reaches the maximum when the content of reactive microgel is 30%. In addition, the nucleation parameter increases first and then decreases with the addition of reactive microgel. When the concentration of reactive microgel is 30%, the value of nucleation parameter reaches the maximum.