Influence Factors of the Impact Toughness of Ultra-high Molecular Weight Polyethylene Molding Compounds for Artificial Joints
The impact toughness of molding compounds for artificial joints is required to reach 180 kJ/m2.The ultra-high molecular weight polyethylene(UHMWPE)is the upstream material of the artificial joint spacer.With the increasing demands for the service life of artificial joints,the toughness of UHMWPE has been put forward with higher requirements.In this paper,the toughening reasons of UHMWPE were studied by using different molecular weight((M)w)resin powders from the perspectives of powder structures and processing methods.It is found that the special virgin powder structure brings higher impact toughness.By analyzing the ratios of crystalline,amorphous and intermediate phases,the size and distribution of crystalline regions as well as the intermediate phase content influence the impact toughness of the products.The post-processing method of isothermal crystallization could significantly increase the sample toughness.It is found that the main reason of the impact toughness increased via the isothermal crystallization is mainly due to the content increase of intermediate phases used for the stress transfer.Intermediate phases improve the efficiency of energy dispersion.Both perspectives demonstrate higher impact toughness of products with higher intermediate phase content.The results provide a useful reference for the developments of high toughness UHMWPE molding compounds for artificial joints.
万方数据
维普
