Bioabsorbable Polylactic Acid Fiber Reinforced Chitosan Composite Rod for Biomedical Materials

A polylactic acid fiber reinforced chitosan composite was fabricated by in-situ precipitation for internal fixation of bone fracture.Scanning electron microscopy(SEM) was done to characterize surface morphology of the polylactic acid fiber/chitosan composites.It would be good compatibility between organic polylactic acid fibers and organic chitosan matrix.SEM images revealed that a good interfacial interaction was obtained in the composites by the in-situ precipitation processing.And a ductile fracture of polylactic acid fiber was observed via SEM image due to physical adsorption and macromolecule chain intertwist between the interfaces of the polylactic acid fiber and the chitosan matrix.Considering that fiber length and concentration are important factor in the fiber enhanced polymer matrix composites,polylactic acid fiber length and concentration were studied chiefly in the composites.The results of mechanical properties indicated that the polylactic acid fiber showed significant improvement in the polylactic acid fiber/chitosan composites.There was a optimum value in the effects on polylactic acid fiber concentration on flexural strength and flexural modulus.However,the flexural modulus of the composites were increased with increasing polylactic acid fiber length in no more than 14 mm.The flexural strength and flexural modulus of the composite with 8%(by mass) polylactic acid fiber in 11 mm length were 108.9 MPa and 4.74 GPa,respectively,which were 54.9% and 170.9% higher than neat chitosan rod.This kind of biodegradation and bioabsorbable chitosan matrix reinforced composite will be widely used in the field of internal fixation in surgery.