Influence of Conditions for Obtaining Polylactide-Based Materials on Their Physical-Mechanical and Rheological Characteristics

Abstract

This paper studies the influence of the conditions for obtaining materials based on the synthetic polymer polylactide on their physical-mechanical and rheological characteristics. These materials are promising for creating temporary biodegradable polymer implants to maintain the mechanical properties of broken bones during the healing period. They are designed to replace the titanium fixators currently used for these purposes, which is due not only to the need for repeated surgery to extract them but also to the fact that the strength and modulus of elasticity of titanium fixators exceed the values of bone strength indicators by an order of magnitude, which can cause the phenomenon of bone resorption and a decrease in its strength. It is established that with an increase in temperature in the plasticization and pressing zone, as well as with an increase in pressure in the press, there is a natural decrease in the viscosity of the polylactide melt, as well as the values of the elastic modulus and breaking stress of solid samples. Varying the cooling rate of the material during the pressing process affects the degree of its crystallinity. At the same time, the lower the cooling rate the greater the degree of crystallinity of the polylactide and the greater the values of the elastic modulus and breaking stress.