Prior to extrusion, PLA pellets and CNCs were dried for at least
12 h at 60 C in a vacuum oven. CNCs were dispersed in the PLA
matrix by melt-blending using a DSM twin-screw microcompounder
(DSM, Holland, Explore, 15 cc) at 200 C first at 30
RPM for 3 min and then at 60 RPM for 5 min. Rectangular specimens
(or bars) (35 mm 12 mm 3 mm) were sequentially prepared
by injection-molding, with the oven temperature set at
200 C and mold temperature set at 50 C. The bars were annealed
at 130 C for 1 h inside of a Carver compression mold.