Sustainable Bioplastics 2016 - Extending polylactide applications by overcoming its drawbacks

摘要

Despite the deep characteristics of polylactide (PLA), such asits origin in biomass and its biodegradability, PLA has severaldrawbacks that limit its use in different applications. A numberof these drawbacks could be in accordance with its glasstransition temperature (Tg = around 60oC) and its very slowcrystallization kinetics. In applications where the servicetemperature requires to be below 60oC, the PLA behaves sortof a very fragile polymer, while in those cases where theservice temperature must be much wider than more than 60oC,the heat can easily deflect the PLA because the degree ofcrystallinity is not high enough. to provide the requiredstiffness. Furthermore, a series of drawbacks arise from themelting conditions of the PLA. Due to the low resistance of thePLA melt followed by its low crystallization rate, forming thefinal products into the required shape is not easy. A similarscenario exists in the processing of the PLA / gas mixture toform high quality foamed structures. In this work, it's shownthat improving the crystallization kinetics of PLA couldsignificantly improve its processability, formability andfoamability, and will extend its service temperature beyond itsTg, and also can improve the mechanical properties of its finalproducts. . Furthermore, mixing PLA with other biopolymerswith high melt strength, high toughness and ductility couldimprove the melt strength and processability of PLA, catch upon its brittleness, and improve its mechanical properties. Theseapproaches provide new routes to expand the use of PLA inmuch broader commodity applications.