聚丙烯/蒙脱土纳米复合材料非等温结晶动力学的研究

用熔融插层法制备聚丙烯 蒙脱土纳米复合材料 ,用DSC手段研究了其非等温结晶行为 ,并与聚丙烯进行了对比 .对所得数据分别用修正Avrami方程的Jeziorny法、Ozawa法和Mo法进行处理 .结果表明 ,用Jeziorny法和Mo法处理非等温结晶过程比较理想 ,而用Ozawa法处理则不太适用 .用Jeziorny法求出的参数Zc和n随冷却速率的增加而增加 ,但复合材料的Zc 和n略大于聚丙烯的Zc 和n ,用Mo法求出的参数F(T)随结晶度的增加而略有增加 ,a几乎未变 ,复合材料的F(T)略小于聚丙烯的F(T) ,复合材料的a约为 1.40略大于聚丙烯的a(其值约为 1.0 4) .按Kissinger方法计算出聚丙烯及聚丙烯 蒙脱土纳米复合材料的结晶活化能分别为 189.37kJ mol,15 5 .6 9kJ mol,说明有机蒙脱土的加入 ,降低了聚丙烯的结晶活化能 ,起到了异相成核的作用

NONISOTHERMAL CRYSTALLIZATION KINETICS OF SYNTHESIS OF POLYBUTADIENE WITH TITANOCENE CATALYST2000-10-20

The nonisothermal crystallization kinetics of polypropylene (PP) and polypropylene/organic\|montmorillonite (PP/Mont) nanocomposite,which was prepared by melt intercalation,was studied by means of differential scanning calorimetry (DSC).The modified Avrami theories of Jeziorny,Ozawa and Mo were used to analyze the data of DSC.The result showed that both the Jeziorny and Mo methods could describe this system very well,but the Ozawa analysis failed.The values of Z c and n increased with increasing cooling rate,and the values of Z c and n of PP/Mont nanocomposite were higher than those of PP at the same cooling rate.The value of F(T) increased,and the value of a had no significant change with increasing degree of crystallinity for PP and PP/Mont nanocomposite,respectively.The values of F(T) of PP/Mont nanocomposite were lower than those of PP at the same degree of crystallinity.The value of a was 1.04,1.40 or so for PP and PP/Mont nanocomposite,respectively.The activation energies have been evaluated by Kissinger method to be 189.37 kJ/mol and 155.69?kJ/mol for the nonisothermal crystallization of PP and PP/Mont nanocomposite,respectively.The addition of organic montmorillonite decreased the activation energy of crystallization of PP,which could be used as nucleating agent during nonisothermal crystallization process of PP.