专业学位研究生工程实践能力培养体系的研究与实践

Key Words:PLLA; Crystallization; NBR; Toughening; Compatibilizer

Abstract:Poly(L-lactide) has derived extensive attention as a most promising biodegradable plastics with the excellent physical and mechanical properties. But it's so stiff and brittle for room temperature applications that restrict its wide applications. This work focused on NBR as toughening agent, adding MAH or DCP or the combination of MAH/DCP as the compatibilizer to increase the compatibility. We found that, by adding DCP only, the toughening system has the optimal mechnical properties, the elongation at break and the impact strength were improved by more than 60 times and 5 times respectively, compared with pure PLLA. This method is simple and operable. For understanding the toughening mechanism in depth,we use polarizing optical microscope and transmission electron microscope to investigate the morphology of the blends. It was found that the system of PLLA/NBR/DCP has the smallest dispersed size and the uniform state. Also the interface is fuzzy which symbolizes the good compatibility. Besides, the PLLA spherulite is small and uniform. All the factors above lead to the good toughness. The fast crystallization rate is beneficial to the stability of the products. Based on the mechanical properties and the morphology of the blends, we discussed the toughening mechanism of PLLA/NBR.

Volume:

Issue:7

Translation or Not:no