title: Study on the mechanical properties of Cu/LDPE composite IUDs.
abstract: BACKGROUND
  The copper/low-density polyethylene composite (Cu/LDPE composite) intrauterine devices (IUDs), which can eliminate or lessen the side effects of existing IUDs, have been developed in our laboratory. As a novel type of copper-containing IUDs, it is not clear whether the mechanical properties of the Cu/LDPE composite IUDs can meet the need of clinical use or not. Therefore, the mechanical properties of the Cu/LDPE composite IUDs have been studied in the present article.
  
  
  METHODS
  The influence of copper particle content and size on the mechanical properties of the Cu/LDPE composite IUDs was analyzed firstly to provide guidance for the material composition design of the Cu/LDPE composite IUDs, and then the BaSO(4)/LDPE composite, which has been applied as a framework of the existing copper-containing IUDs in clinical use for decades, has been used as reference to judge whether the mechanical properties of the Cu/LDPE composite IUDs can meet the need of clinical use or not. However, the mechanical properties of IUDs cannot be characterized directly. Therefore, the mechanical properties of both the Cu/LDPE composite IUDs and the framework of the existing copper-containing IUDs were investigated by means of tensile test using standard tensile samples, and the fracture surface morphology of the tensile samples was characterized by scanning electron microscopy (SEM).
  
  
  RESULTS
  Both the elongation at break and the tensile strength decrease with increasing of copper particle content and increase with increasing of the copper particle size, while the elastic modulus shows an opposite tendency. The tensile strength and elastic modulus of both the Cu/LDPE microcomposite IUDs and the Cu/LDPE nanocomposite IUDs with 25 wt.% of copper particles are higher than those of existing copper-containing IUDs (TCu220C; its framework is made of the BaSO(4)/LDPE composite with 20 wt.% of BaSO(4)).
  
  
  CONCLUSIONS
  The content and size of the copper particles have significant effect on the mechanical properties of Cu/LDPE composite IUDs. The mechanical properties of both the Cu/LDPE microcomposite IUDs and the Cu/LDPE nanocomposite IUDs with 25 wt.% of copper particles were superior to that of existing copper-containing IUDs, indicating that the novel Cu/LDPE composite IUDs can satisfy the requirement of mechanical properties in clinical application.
authors.affiliation: State Key Laboratory of Material Processing and Die and Mould Technology, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tang
authors.forename: Xianping
authors.initials: X
authors.lastname: Xia
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Changsheng
authors.initials: C
authors.lastname: Xie
mesh_terms: D005260:Female; D006801:Humans; D007435:Intrauterine Devices, Copper; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D020959:Polyethylene / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D020959:Polyethylene