Poly(lactic acid) based polymer composites for biomedicine

Main properties of biodegradable polymer composites on the base of poly(lactic acid) (PLA) filled with hydroxyapatite (HA) were studied by different methods such as dielectric spectroscopy in frequency domain, optical microscopy, wide-angle X-ray diffraction and tensile tests. All composites were fabricated by melt compounding. It has been found that values of real part of the complex permittivity of PLA-HA composites are increased by 15–30% compared to that for neat PLA, while loss factor tan8 does not exceed 0.02. The degree of crystallinity of PLA-HA composites is increased by 3.2 and 6.15 times with filling by HA from 25 to 50 wt % respectively compared to that for neat PLA. All studied mechanical parameters, except for Young's modulus, tend to decrease with increasing filler content due to an increase in the stiffness of composites.