PLA-Sago Starch Implants: The Optimization of Injection Molding Parameter and Plasticizer Material Compositions

Abstract

Previous research extensively characterized PLA blends for various biomedical applications, especially in polymer-based biodegradable implant fixations, offering advantages over metallic counterparts. Nevertheless, achieving an optimal PLA mixture with both mechanical resistance and fast biodegradability remains a challenge. Currently, literature still lacks insights into the manufacturing parameter impact on sago starch/PLA in combination with PEG plasticizer. The objective of this study is to assess variations in injection molding temperatures and sago/PLA/PEG weight compositions to identify the optimal combination enhancing miniplate mechanical properties and biodegradation behavior. Mechanical tests reveal that incorporating PEG into pure PLA yields high mechanical performance, correlating linearly with increasing injection temperature. However, the interaction once the three materials are mixed decreases mechanical performance across tested temperatures. Higher biodegradation rates are observed with a larger weight composition of the hydrophilic behavior attributed to sago starch presence. The observed novelty in PLA mixed with 20% sago starch and 10% PEG at 170 °C indicates a better performance in elastic modulus and elongation at break also the degradation rate, emphasizing the role of injection temperature in molding miniplate implants. In conclusion, the interplay of injection molding parameters and material compositions is crucial for optimizing PLA-based miniplate implants, with potential contributions to tissue implants rather than bone implants due to their mechanical limitation.