| `Calcium phosphate is a preferred implant material due to its excellent biological properties. Because of its brittleness and fatigue, failure in the body, this kind ceramic is mainly used for unload bearing repair. To avoid its poor fatigue properties in loaded applications, HA/polymer composites were widely studied. In the first part of the dissertation, Nano-apatite/Polyamide-6 (HA/PA6) composite has been obtained by ring-opening co-polymerization method. Nano-HA content in the composite can reach 40wt%. The structure, property and biocompatibility were tested. The nano-HA in composite keeps the original morphological structure and HA particles are uniformly distributed in the PA6 matrix. The phase composition, morphology, dissolution and precipitation in SBF were characterized by XRD, FTIR, EDS and SEM. The composites have good homogeneity, and the diameter of HA in the composite is about 30-50 nanometer. The composite has good physical and mechanical property and good biocompatibility. The in vitro bioactivity of PA-6 and HA/PA-6 were studied in SBF ( simulated body fluid) . The results showed that PA-6 was not bioactive in SBF, Ca-P compound was slowly deposited on the surface of PA-6, but it was not HA. HA/PA-6 composite was chemically active in SBF, and dissolution and deposition of Ca, P ions happened during the culture in SBF. The Ca-P precipitate on the surface of HA/PA-6 composite surface was carbonated-apatite. Its weight lost by about 2% every week. This kind of composite could be one of the best potential bioactive materials for load-bearing bone, substitution or as bioengineering material.In the second part, the copolymer of poly( 1,4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)[p-PPS-m-PPSA] and its nano HA composite [HA/ p-PPS-m-PPSA] has been obtained by polycondensation in 1-methly-2-pyrrolidone(NMP), and nano apatite content in the composite can reach 60wt%. The structure and property of the copolymer and its nano HA composite were studied through IR, XPS, TEM, and AFM. The copolymer has high molecular weight(n =0.467), and excellent thermal property. There is a stable interface formed betweenHA and p-PPS-m-PPSA copolymer in the composite. HA keeps the original morphological structure and crystal behavior in the composite. The composite has good homogeneity and outstanding thermal stability. HA particles are uniformly distributed in the composite. The diameter of HA in the composite is about 40-60 nanometer. The poly (2,4-phenylene sulfide acid) in copolymer can increase affinity to apatite and does not decrease the melting point and thermal stability of copolymer. The p-PPS-m-PPSA and its nano HA composite are very stable in SBF. Ca-P compound was deposited on the surface of copolymer step by step, and the Ca/P ratio of the Ca-P precipitate on the surface of the copolymer was 1.63 in the fourth week after culture in SBF, near to the stoichiometric HA. Ca-P compound was deposited more fast on the surface of HA/ p-PPS-m-PPSA composite than on the copolymer. The Ca-P precipitates both on copolymer and on composite were HA, and carbonated HAduring the incubation in SBF. The p-PPS-m-PPSA copolymer and HA/ p-PPS-m-PPSA composite were stable and bioactive in SBF.In the third part, PA-6, PA-66, p-PPS-m-PPSA, HA/PA-6, HA/PA-66 and HA/ p-PPS-m-PPSA composite were cultured in SBF. The stability of these polymers and composite was shown as following:HA/p-PPS-m-PPSA> p-PPS-m-PPSA> PA-66) HA/PA-66> PA-6>HA/PA-6HA/p-PPS-m-PPSA was the most stable material in the SBF. Its weight almost did not change in the first two weeks during the incubation in the SBF, and increased a little in the third and fourth week after carbonated the HA deposited on the surface of the composite. The HA/PA-6 composite was the most unstable material in the SBF. Its weight lost about 2% every week during the incubation in SBF. The Ca-P precipitate in SBF was much more slowly on the surface of the polymers than on the surface of composites. And there was almost no precipitate on the PA-66 surface. The order...
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