Preparation and characterization of hydroxyapatite/poly(ethylene adipate) hybrid composites.
Hydroxyapatite/poly(ethylene adipate) (HAp/PEA) composites were prepared by in situ ring-opening polymerization of cyclic oligo(ethylene adipate) (C-OEA) within the porous HAp templates. HAp was firstly prepared by a co-precipitation method using calcium hydroxide and phosphoric acid and then shaped as a rectangular porous template. PEA precursor was synthesized by bulk polymerization of dimethyl adipate and ethylene glycol in the presence of tetraisopropyl orthotitanate. C-OEA was obtained by cyclo-depolymerization of the PEA precursor under high dilution condition using dibutyl tinoxide as a catalyst. The HAp/PEA composites were prepared by immersing the porous HAp templates in the mixture solution of C-OEA and dibutyl tinoxide catalyst overnight and ring-opening polymerizing at 180, 200 and 220 degrees C for 24 h. The ring-opening polymerized PEA formed as a thin film coating on the surface of porous HAp template. The HAp/PEA composites contained PEA in the range of 20-26 wt%. The weight-average molecular weights of ring-opening polymerized PEA were in the range of 3800-4450 g/mol. Compressive strength of the HAp/PEA composite was significantly increased from 25 MPa in the porous HAp template to 140 MPa in the composite.
Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok, Thailand.
Punnama
P
Siriphannon
Pathavuth
P
Monvisade
D019245:Compressive Strength; D003500:Cyclization; D017886:Durapatite / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
D011091:Polyesters; C539080:poly(ethylene adipate); D017886:Durapatite