Crystallization Behavior Of Cu/LDPE/MVQ Composite

Low density polyethylene (LDPE) and methyl vinyl silicone rubber（MVQ） areoften used to prepared Copper-containing intrauterine contraceptive devices (Cu-IUDs).The copper/low-density polyethylene/methyl vinyl silicone rubber(Cu/LDPE/MVQ)composite is obtained and used to prepared the novel IUD.To obtain an excellent contraceptive effect, the nonisothermal crystallization behavioris studied. Three groups samples are prepared to investigate the effects of thecompositions on the nonisothermal crystallization behavior. The content of fumed silica,LDPE and copper particles are changed during the process. The Differential scanningcalorimetry (DSC) curves are tested under N2atmosphere.The results of spectrum analysis show that the Cu/LDPE/MVQ composite is the justthe mixture of copper, LDPE and MVQ. The fumed silica dispersed in the LDPE act as thesticking point and the heterogeneous nucleation for the crystallization at the same time.The crystallinity degree reach the minximum in Cu/LDPE/MVQ composite when thefumed silica content is40phr. The LDPE dispersed in MVQ evenly just like islands in theocean when the content is10wt%. And they connect with each other with a reticularstructure with the increase of the content of LDPE. So that the Cu/LDPE/MVQ compositeshow a lower crystallinity degree. Furthermore, the copper particles dispersed in thecomposite act as a heterogeneous nucleation for the crystallization of the composite andthey hinder the movement of the molecule chains at the same time. The crystallinity reachthe maximum in the composite when the copper micro-particles content is10wt%. It ismore easy and faster for the composite to crystallize when the copper particles are added.