Preparation method of polylactic acid composite material by use of oriented distribution of nano-hydroxyapatite for enhancement

Abstract

The invention relates to a preparation method of a polylactic acid composite material by use of oriented distribution of nano-hydroxyapatite for enhancement, and the method is as follows: calcium nitrate, ammonium phosphate and gelatin aqueous solution are mixed for preparation of hydroxyapatite suspension by heating, PH adjusting and homoiothermy; polylactic acid is dissolved in an organic solvent and then is added to the suspension for mixing, heating and centrifugal drying to prepare hydroxyapatite-polylactic acid composite powder and granulate; and multi-channel shear extrusion deformation of an injection-molded composite molding material is performed by an equal channel angular pressing die under certain process conditions to obtain the target product. The advantages of the preparation method are that: gelatin is introduced to improve the uniform distribution of the hydroxyapatite in a polylactic acid matrix and increase the interface bonding strength; by multi-channel equal angular pressing, the rod-like hydroxyapatite can be directionally evenly distributed in the polylactic acid matrix, the comprehensive mechanics performance of the composite material can be improved, and the preparation process is simple, low-cost, and more suitable for productization.

Description

technical field [0001] The invention relates to the preparation technology of materials for medical surgery, in particular to a preparation method of nano-hydroxyapatite orientation distribution reinforced polylactic acid composite material. Background technique [0002] Medical metal materials (stainless steel, cobalt-based alloys, titanium alloys, etc.) are currently the most widely used internal fixation materials for fractures. However, the mismatch with the rigidity of human bones often leads to stress shielding; under the action of physiological corrosion and wear, toxic substances may be released. Metal ions and microparticles cause local tissue inflammation; the material cannot be degraded, and must be removed through a second operation after bone healing, which increases the economic and psychological burden and physical pain of the patient. Therefore, replacing traditional non-degradable metal materials with in vivo degradable materials has attracted more and more...

AI Technical Summary

Problems solved by technology

But so far, the problems of insufficient initial mechanical properties (strength, toughness) of such composites and premature loss of their mechanical strength after exposure to physiological environments have not been well resolved, mainly in the case of HA dispersed in PLA matrix. Uniformity, HA and PLA two-phase interface binding problems and lack of effective means of processing and forming toughness have not been well resolved.