目的 制备羟丙基纳米纤维素/羟基磷灰石(NCC-HPC/HA)纳米复合材料。方法 以环氧丙烷作为改性剂，对纳米纤维素(NCC)表面进行化学修饰，获得羟丙基纳米纤维素(NCC-HPC)，以提高NCC的表面疏水性及改善其分散性。在此基础上，以NCC-HPC为成核点，采用共沉淀法制备NCC-HPC/HA纳米复合材料，研究复合材料的结构与性能。结果 采用共沉淀法在改性后的纳米纤维素表面成功地合成了羟基磷灰石纳米球。由分析证实，经环氧丙烷表面改性后的NCC，几乎没有发生晶体结构变化，疏水性得到了提高，再分散性得到了改善，且能稳定存在于水和其他有机溶剂体系中，NCC-HPC与水的接触角由17°增加到55.3°。NCC-HPC/HA纳米复合材料的表面均匀分布着钙、磷元素，其Ca/P原子比为1.64，接近真实骨的钙磷比。在2 MPa条件下压制的复合材料的力学性能显示，与未经表面修饰的NCC相比，经表面修饰的纳米纤维素制备的NCC-HPC/HA纳米复合材料的力学性能有所提升。拉伸强度可达到3.48 MPa，提高了6.7%;弯曲强度可达到5.22 MPa，提高了4.4%;压缩强度可达到2.11 MPa，提高了4.7%。结论 经羟丙基改性的NCC，疏水性得到提高，在水溶液中的分散性明显改善。以此为基础制备的NCC-HPC/HA纳米复合材料中，球状纳米羟基磷灰石(n-HA)均匀分布在线状NCC-HPC上，具有较好的力学性能和热稳定性，适用于骨组织工程应用。

The work aims to prepare hydroxypropyl nano-cellulose/hydroxyapatite (NCC-HPC/HA) nanocomposites. The surface of nano-cellulose (NCC) was chemically modified with propylene oxide as modifier to obtain surface modified nano-cellulose (NCC-HPC) to improve the surface hydrophobicity and dispersion of NCC. On this basis, NCC-HPC/HA nanocomposites were prepared by co-precipitation method with NCC-HPC as nucleation point, and the structure and properties of the composites were studied. Hydroxyapatite nanospheres were successfully synthesized on modified nanocellulose by co-precipitation method. It was confirmed by analysis that the NCC surface modified by propylene oxide had almost no crystal structure change, its hydrophobicity and redispersion were improved, and it could stably exist in water and other organic solvent systems. The contact Angle between NCC-HPC and water increased from 17° to 55.3°. The surface of NCC-HPC/HA nanocomposite was uniformly distributed with Ca and P elements, and the Ca/P ratio was 1.64, which was close to the Ca/P ratio of real bone. The mechanical properties of the composites pressed at 2 MPa showed that:Compared with the NCC without surface modification, the mechanical properties of NCC-HPC/HA nanocomposites prepared by surface modification of nanocellulose were improved. The tensile strength could reach 3.48 MPa, an increase of 6.7%, the bending strength could reach 5.22 MPa, an increase of 4.4%, and the compression strength could reach 2.11 MPa. That‘s a 4.7 percent increase. The hydrophobicity of NCC modified by hydroxypropyl was improved, and its dispersion in aqueous solution was obviously improved. It was due to the introduction of new groups on the surface of NCC, which made the surface of particles become fluffy, particles were not tightly stacked, and the adsorption between particles was greatly weakened. The spherical nano-hydroxyapatite (n-HA) in the NCC-HPC/HA composite prepared on this basis was uniformly distributed on the linear NCC-HPC, which had good mechanical properties and thermal stability, and was suitable for bone tissue engineering applications.