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 toinvestigate 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.