Abstract: RADIATION EFFECT ON ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENESong Chunlei Wei Yujie Luo Yunxia(Changchun Institute of Applied Chemistry,the Chinese Academy of Sciences,Changchun 130022)ABSTRACTUltrahigh molecular weight polyethylene (UHMWPE) can be used at a substitute of the bone of human body sketelon.Before being set in to human body,it needs to be sterilized with high energy radiation.Therefore,it is of considerable significance to study the effect of radiation on UHMWPE.Because of ultrahigh molecular weight of this material,there would be a lot of entanglements at molecular chain,its radiation effect would be quite different from that of polyethylene with normal molecular weight.The radiation effect on UHMWPE was studied by means of density and DSC analysis,It has been shown that the density increases with the increase of radiation dose up to 113 MGy monotonically.The heat of fusion per unit weight of sample and melting point of UHMWPE increase with dose too,especially at the lower dose of radiation.It could be concluded that during the period of radiation,there would be additional crystallization or crystal perfection taken place.Key words Ultrahigh molecular weight polyethylene Radiation effect Radiation sterilization