Abstract

The original formulation and mechanical characterization of poly 3-hydroxybutyrate) /nano-sized diamond polymer composite were development with potential for biomedical application as bone fracture fixation device. The P(3HB)/ND nanobiocomposites were prepared by efficient nano diamond (ND) dispersion in P3HB solution by solvent evaporation process. The loading of ND particles in the bulk nanocomposite was determined by thermogravimetric analysis (TGA) yielding nanocomposites with 8.8, 11.8, 13.7 and 19.7 wt% of ND. Standard shape specimens for bending test (ASTM D 790) and Dynamic mechanical analysis (DMA) were prepared by molding in a hydraulic press at 135° C and 8 tons press for 35 minutes. Bending tests were carried out by using a universal mechanical testing machine Instron 5582. The three point bending tests were conducted at a cross-head speed of 1.0 mm/min. Vickers microhardness was conducted in a Shimadzu HMV-2 microhardness machine with a load of 300 g by 20 seconds. At least 15 indentations were made for each formulation and the Dynamic mechanical test in Q DMA 800 TA Instruments at 1Hz frequency and 30C/min as heating rate. The use a ND in the P(3HB) formulations improvement the mechanical properties of P3HB at concentrations studied. The experimental flexural modulus of the P(3HB)-9%ND nanobiocomposite was 4,3 ± 0,63 GPa, which is higher than the trabecular bone property that ranging from 0,02 to 0,5 GPa, and also can be compared to the lower limit of the results of 3 to 30 GPa reported for the cortical bone. The experimental flexural strength of the nanobiocomposites studied were higher than the flexural strength of 7,4 MPa for the trabecular bone. These improvements could be associated to ND’s physical properties, homogeneous dispersion of ND particles and efficient interaction/adhesion between P3HB matrix and ND in the nanobiocomposites.