稀土镧改性PP流变性能的研究

Rheological behavior of PP modified with lanthanum benzoate

以氧化镧为原料,利用化学沉淀法制备氢氧化镧,再以不同比例的氢氧化镧与苯甲酸合成了两种稀土化合物苯甲酸镧,将苯甲酸镧与聚丙烯(PP)共混,制得两种改性PP混合物。研究了苯甲酸镧对PP流变性能的影响。结果表明:苯甲酸镧加入到PP后,PP共混体系为非牛顿假塑性流体,其表观粘度随剪切速率增大而减小;随着苯甲酸铡含量的增加,PP共混体系的非牛顿指数降低,流变性能得到改善;2种PP共混物的粘流活化能分别达到58.60 kJ/mol和56.85 kJ/mol。

Two kinds of lanthanum benzoate, a rare earth compound, were obtained from benzoic acid and lanthanum hydroxide, which was prepared from lanthanum oxide via chemical precipitation, at different proportions. Two kinds of polypropylene （PP） blend systems were prepared by blending PP with these two kinds of lanthanum benzoate. The effect of lanthanum benzoate on the rheological behavior of PP was studied. The results showed that the PP blend systems were non-Newtonian pseudoplastic fluid, whose apparent viscosity was decreased with the increase of shearing rate. The non-Newtonian index （ n ） of the modified PP blend systems was decreased while increasing the content of lanthanum benzoate, thus the rheological behavior was improved. The viscose flow activation energy of these two kinds of PP blend systems was 58.60 kJ/mol and 56.85 kJ/mol, respectively.