Study On BF Enhancing Machining Performance And Aging Resistance Of PLA/PHB Degradable Materials

Considering the application prospect of degradable materials in the production of processing and molding,PLA and PHB are used as environmental protection and degradable biological materials,basalt fiber(BF)is used as a promising green filler.It will be of great significance to mix BF and biodegradable biocomposite materials to prepare environment-friendly and biodegradable high-performance biocomposite materials that can replace petroleum-based plastics.Most of the studies on PLA/PHB at home and abroad focus on thin films,but few studies on PLA/PHB composites in molding products.The effect of BF addition to PLA/PHB composite on its processing and aging resistance is rarely involved.This work will investigate the effect of suitable BF content on the processing and aging resistance of PLA/PHB composites,and provide reference for the application of BF/PLA/PHB composites in environmental protection products.BF/PLA/PHB composites were prepared by injection molding process using PLA,PHB and BF as raw materials by one-step reactive melting blending.In this paper,BF reinforced PLA/PHB composites were used as research materials,and tensile tests were conducted on the splines prepared.When BF was increased to 10wt% in BF/PLA/PHB composites,the tensile strength of the composites reached the maximum,but the increase was significantly weakened.At the same time,the elongation at break of the composite decreased first and then increased with the increase of BF content.X-ray diffrotometer and DSC analysis showed that BF played a heterogeneous nucleation role in PLA/PHB matrix,and the crystallinity of PLA/PHB matrix was improved.When BF content was over 5wt%,the increase of crystallinity of the composite was significantly reduced.The glass conversion temperature of composites increases with the increase of BF content,and BF has little effect on the melting point of composites.According to the rotary test analysis,when the temperature is 220℃,the rheological property of the composite material is the best,and when the BF content of BF/PLA/PHB increases to 2wt%,the rheological seepage threshold is reached,and the BF content continues to increase,the complex viscosity of the composite material will be significantly improved,resulting in poor fluidity of the material,which is not conducive to engineering application and processing.The tensile strength of BF/PLA/PHB composites decreases with the humidity and heat treatment time increasing,but the decrease amplitude gradually slows down.The modulus and viscosity of the material also show a trend of continuous decline.However,the longer the humidity and heat treatment time,the smaller the decrease.In addition,when BF content was 10wt%,the decrease was the smallest.