Toughening Of Poly (Lactic Acid) By Elastomers For Automotive Inner Decorated Components

The experiment uses ethylene-propylene-non-conjugated diene terpolymer(EPDM) ethylene-vinyl acetate copolymer(EVA),Polyethylene-octene elastomer (POE) and SEBS as the plasticizer of polylactic acid(PLA). Appropriate compatibilizer has been selected to conduct tests on its blends with different proportion from the aspects of impact and tensile. Observed by SEM microstructure of composite materials Also DSC curve was measured when a simple blend of polylactic acid was conducted.The experimental results of PLA/EPDM blend system show:EPDM does little contribution to the Impact Property of the system, but the compatibilizer can increase the notched impact strength and prevent the Izod impact strength, Tensile strength and Young's modulus from decreasing. If the compatibilizer's proportion is correct,the elongation at break will has a substantial increase.Using EPDM as toughening and POE-g-MAH as compatibilizer, when the proportion of PLA, EPDM, POE-g-MAH is 80/10/10, Mechanical properties of composite materials achieve the best. The result of DSC experiment shows, EPDM can promote crystallization of polylactic acid in the cold, and slightly reduce the heat required to melt.The experimental results of LA/EVA blend system show:it has a certain toughening effect using the EVA as a toughening of polylactic acid. EVA can obviously increase the notched impact strength of the blends. To a certain extent, the compatibilizer can compensate for the decline of the tensile properties. In PLA/EVA blend, using EVA-g-MAH as compatibilizer, when the proportion of PLA, EVA, EVA-g-MAH is 80/5/15, Mechanical properties of composite materials achieve the best. The result of DSC experiment shows, EVA will inhibit crystallization of polylactic acid in the cold, and reduce the heat required to melt.The experimental results of PLA/POE blend system show:it has a good toughening effect using the POE as a toughening of polylactic acid. POE can obviously increase the notched impact strength of the blends. And to a certain extent, the compatibilizer can compensate for the decline of the tensile properties. In PLA/POE blend, using POE-g-GMA as compatibilizer, when the proportion of PLA, POE, POE-g-GMA is 80/5/15, Mechanical properties of composite materials achieve the best. The result of DSC experiment shows, POE can promote crystallization of polylactic acid during the cooling process, and the addition of the compatibilizer makes PLA cold crystallization peak move further to the low temperature.The experimental results of PLA/SEBS blend system show:using SEBS as the toughening of polylactic acid shows excellent effect. SEBS blends can greatly enhance the impact strength, but compatibilizer does not make the mechanical properties of composite materials to further improve. The result of DSC experiment shows, SEBS can inhibit crystallization of polylactic acid in the cold, and the addition of the compatibilizer makes PLA cold crystallization peak move further to the high temperature.