Study On The Preparation And Properties Of High Performance PLA/BF Composites

Material is known as one of the three pillars of contemporary civilization, andenvironment is the basis of human survival. With the continuous development of society"white pollution" increasingly prominent. Research and development of biodegradablematerials is imminent.PLA is environment-friendly polymer materials and it can becompletely biodegradable,and it is synthesized with renewable plant resources.It belongs tothe aliphatic polyester,and it has been widespread concern because of its excellentbiodegradability and biocompatibility. Its application has been largely restricted becauseof its obvious shortcomings such as high price,poor heat resistance and high brittleness.Many researchers both at home and abroad have lot of studies on modification of polylacticacid in order to use PLA more better. In this thesis, basalt fiber and EVA was used tomodifiy PLA. Infrared spectroscopy, computer control universal testing machine, scanningelectron microscopy (SEM), DSC was used to test material properties.Study on the properties of basalt fiber reinforced polylactic acid composites. PLA/BFcomposites was prepared by melt blending in mastication machine.From the mechanicalproperties of test results,we can see, the mechanical properties of PLA/BF compositesincreases with increasing fiber content, when the content of basalt fiber was20(wt)%,thetensile properties of PLA/BF composites reached up to the best,of which the tensilestrength was56.08MPa and has been improved by50.14%. When the content of basaltfiber was15(wt)%, the impact properties of PLA/BF composites reached up to28.038KJ/m2and has been improved by126.7%, but the elongation at break decreased. Scanningelectron microscopy results show that the adhesion of the fiber and the matrix of PLA/BFcomposites which was treated by coupling agent was better than the untreated ones. DSCanalysis showed that basalt fiber has little influence on the melting point and glasstransition temperature of PLA/BF composites, but Melting enthalpy and crystallinity was significantly improved, this showed that the basalt fiber have played the role of thenucleation.In order to further improve the performance of the PLA/BF composites, In thisstudy，EVA particles ware added into PLA/BF composites. From the mechanicalproperties of test results,we find the tensilel properties of PLA/BF/EVA compositesdecreases with increasing EVA content,but elongation at break and impact strengthincreased obviously. when the content of EVA was20(wt)%, the impact properties of PLA/BF/EVA composites reached up to61.735KJ/m2and has been improved by120%,and theelongation at break increased by49times. DSC analysis showed that EVA can furtherimprove the crystallinity.