羟基磷灰石的表面改性对羟基磷灰石/聚醚醚酮复合材料力学和摩擦性能的影响

采用共沉淀法制备纳米羟基磷灰石（HA），并用硅烷偶联剂KH560对其进行表面改性；然后，以聚醚醚酮（PEEK）为基体，通过热压成型工艺制备原始HA/PEEK与改性HA/PEEK复合材料。考察两种HA的引入对复合材料结构、力学性能和摩擦性能的影响。利用XRD、FTIR、FESEM、拉伸测试、DMA和摩擦测试对两种HA/PEEK复合材料的结构和性能进行了表征。结果表明：HA表面引入了硅烷偶联剂KH560；改性前后HA的晶型结构没有明显改变；两种HA对PEEK基体的结晶结构也没有产生影响；改性HA在PEEK基体中分散均匀；与纯PEEK相比，10wt%改性HA/PEEK复合材料的储能模量增加了55.56%，玻璃化温度增加了3.6℃，磨痕深度降低了31.1%，有效改善了复合材料的热力学性能和摩擦性能；改性HA/PEEK拉伸强度为68.33 MPa，能够满足人骨的强度要求。

Effect of surface modification of hydroxyapatite on mechanical and tribological properties of hydroxyapatite/polyetheretherketone composites

The nano-hydroxyapatite (HA) was prepared by coprecipitation method, and the surface was modified by grafting silane coupling agent KH560. Then, the HA/polyether ether ketone (PEEK) composites with 10wt% as-synthesized or surface-modified HA were prepared by hot-press moulding procedure. The effects of different HA on the structure, dynamic mechanical and tribological properties of the composites were investigated. The HA/PEEK composites were characterized by XRD, FTIR, FESEM, tensile test, DMA and friction test. The results show that silane coupling agent KH560 is grafted onto the surface of HA, and the crystal structure of as-synthesized and surface-unmodified HA shows no distinct change. In addition, the addition of different HA into PEEK matrix has almost no influence on the crystal structure of PEEK. Besides, the modified HA is homogeneously dispersed in PEEK matrix. Compared with pure PEEK, the PEEK with the addition of 10wt% surface-modified HA is improved in the storage modulus and glass transition temperature by about 55.56% and 3.6℃, respectively, and reduced in the scratching depth by about 31.1%. Therefore, the thermodynamic and tribological properties of the composites are greatly improved. The tensile strength of surface-modified HA/PEEK composites is 68.33 MPa, which can match well with the strength requirement of human bones.