Abstract: An in-situ processing combined with solution co-mixing approach was developed in the preparation of poly(methyl methacrylate)(PMMA) matrix bio-composites using hydroxyapatite (HA) nano-particles and short carbon fiber (C_f) as reinforced materials. The influences of HA particles on the mechanical properties and microstructures of the HA-C_f/PMMA composites were investigated. The mechanical properties were tested by universal testing machine. The phase compositions and fracture surface morphologies of the asprepared HA-C_f/PMMA composites were characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscope (FT-IR). The results show that the interface bonding between HA and PMMA matrix and the mechanical properties of HA-C_f/PMMA composites are obviously improved by surface modification of HA with lecithin as coupling agent. With the increase of lecithin-modified HA mass fraction, the flexural strength, tensile strength, compressive strength, flexural modulus and tensile modulus of the as-prepared HA-C_f/PMMA composites firstly increase and then decrease. When the surface modified HA particles mass fraction is 8%, the dispersion of HA nano-particles in PMMA matrix is uniform and the flexural strength, tensile strength, flexural modulus and tensile modulus of the HA-C_f/PMMA composites reach the maximum value.

Key words: nano-hydroxyapatite (HA), bio-composites, mechanical properties