The Development Of MHA/PCL Biodegradable Materials

The hydroxyapatite (HA) was prepared by the method of sol-gel and its surface modification was carried out using 3- (trimethoxy) propyl methacrylate silane coupling agent (KH-570). The modified HA(MHA)/PCL (ploycaprolactone) biodegradable composites were prepared. The mechanical interfacial and thermal properties of the composites have been studied in the present master thesis.Making use of the orthogonal design experiments, the sol-gel technique has been prepared to HA. Modified HA particles(MHA) were prepared using silane coupling agent (KH-570), respectively in non-proton medium (toluene) and proton medium (H₂OH-EtOH). Modified HA particles were characterized by FT-IR. The result indicated that in non-proton system(toluene), the -OR group could be coupled with surface -OH group in HA, yielding a new chemical structure "P-O-Si", but in H₂OH-EtOH system , group -OR was hydrolyzed to Si-OH group by H2OH, yielding a new chemical structure "Si-O-Si". The surface modified HA(MHA) of properties have been studied. The results showed that silane coupling agent was a kind of excellent surface modification coupling agent with good reactivity. The optimum addition of KH-570 coupling agent was 0.8wt%.Making using of melt blending and heat press technique to make HA(MHA)/PCL composites, through a series of performance tests (including tensile test impact test bending test), it was proved better machine function. SEM was employed to study surface and interface of modified HA(MHA)/PCL composites. The result indicated that the modified HA(MHA) particles were homogeniously dispersed in the composites. Interface between MHA and PCLmatrix was more obscure than that of HA and PCL, which showing that there was an improved interface between the modified HA(MHA) toughened phase and polymer matrix. Relationship of swelling property of the composites as a function of time was investigated. The result indicated that the swelling equilibrium of HA/PCL was reached by 48h and the swelling equilibrium of MHA/PCL was reached after 48h. Their swelling percentages were higher than that of un-modified sample at equilibrium. A possible swelling mechanism was suggested.