Poly(l-lactide acid) composites containing needlelike fibers assembled by C60 with improved crystallization and thermal properties

The poly(l-lactide acid) (PLLA) composites containing needlelike C60 fibers (C60Ns) with lengths ranging from several hundred microns to a centimeter were prepared by a simple solution blending method. The study on the composition and structure of the C60N in PLLA film indicated that the black needlelike fibers were mainly assembled together by monomeric C60 and retained the face-centered cubic (fcc) lattice structure of pristine C60. A slow evaporation rate of solvent and a higher C60 loading positively affected the length of the C60N. As far as the preparing method of the PLLA/C60N composites was concerned, one obvious advantage was that the formation of C60N and its compounding with the PLLA matrix could be realized simultaneously and conveniently during the same evaporation process of the solvent. On the other hand, the C60Ns were individually dispersed through the PLLA matrix, which further improved their modification effects for PLLA, thus, the PLLA/C60N composites showed superior crystallization property and thermal stability to the corresponding PLLA/C60 composites.