聚丙烯/纳米碳酸钙原位聚合复合材料非等温结晶动力学研究

用原位聚合复合法制备PP/纳米CaCO3复合材料,用DSC法研究了不同纳米粒子含量的等速结晶性能和非等温结晶行为。对所得数据分别用修正Avrami方程的Ozawa法和Mo法进行处理,表明Mo法处理PP/CaCO3纳米复合材料非等温结晶过程比较理想。Mo法所得的参数F(T)随结晶度的增加而增大,a随结晶度的增加而增大,但幅度不大。表明降温速率越快,单位结晶时间达到的结晶度越高,各降温速率下的结晶方式基本不变。等速结晶研究表明,纳米碳酸钙的加入起到了结晶成核剂作用。用Kissinger方法计算出PP/纳米CaCO3原位复合材料的活化能为202 4kJ/mol。

Nonisothermal Crystallization Kinetics of Polypropylene/nano-CaCO3 In-situ Composites

The uniform speed crystalline at varied content of nano-CaCO_3 and the nonisothermal crystallization kinetics of polypropylene/nano-CaCO_3 composite prepared by in-situ polymerization were studied by means of Differential Scanning Calorimetry(DSC).The modified Avrami theories of Ozawa and Mo were respectively used to analyze the data of DSC.The result showed that Mo methods could describe this system very well.The value of F(T) increased with increasing degree of crystallinity for PP/ nano-CaCO_3 composite,and the value of a increased,but not significantly.It showed that the faster of the cooling rate,the higher of the crystallinity at the unit crystallization time.And the crystallization modes did not significantly change.It also showed that CaCO_3 nano-particles could be used as nucleating agent during non-isothermal crystallization process of PP.The activation energies were evaluated by Kissinger method to be 202 kJ/mol for PP/ nano-CaCO_3 composite.