title: Investigation of nanocomposites based on semi-interpenetrating network of [L-poly (epsilon-caprolactone)]/[net-poly (epsilon-caprolactone)] and hydroxyapatite nanocrystals.
abstract: In this paper the semi-interpenetrating network (semi-IPN) technique was used for the first time to prepare bone implant composites containing hydroxyapatite (HAP) nanocrystals. The prepared nanocomposites are expected to combine several property advantages including good mechanical strength, modified degradation rate and excellent osteoconductivity. The semi-IPN matrix based on the linear poly (epsilon-caprolactone) (L-PCL) and the network poly (epsilon-caprolactone) (net-PCL) structures are revealed to be phase separation structures. The morphology of net-PCL is featured by intracrosslinked microdomains (1-10 microm) that further interconnect with each other to form the network over the whole sample. The net-PCL component is totally amorphous at room temperature for the nanocomposites containing HAP up to 12.3 wt%. Further, the crystallinity of L-PCL is greatly decreased due to the presence of net-PCL as compared with that for pure L-PCL. The incorporation of L-PCL into the net-PCL network could significantly improve the mechanical properties of pure net-PCL. A great improvement in mechanical properties is observed for the nanocomposites if the HAP content is increased to 15.8 wt%. This transition is in agreement with that the net-PCL component changes from amorphous state to crystalline state at this composition.
authors.affiliation: Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Academia Sinica, P.O. Box 415, Chengdu 610041, People's Republic of China. jianyuan.hao@nottingham.ac.uk
authors.forename: Jianyuan
authors.initials: J
authors.lastname: Hao
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Shaobing
authors.initials: S
authors.lastname: Zhou
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Xianmo
authors.initials: X
authors.lastname: Deng
mesh_terms: D001672:Biocompatible Materials; D003460:Crystallization; D017886:Durapatite; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008854:Microscopy, Electron; D008968:Molecular Conformation; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D007202:Indicators and Reagents; D011091:Polyesters; C016240:polycaprolactone; D017886:Durapatite