Abstract
This study describes mechanical properties of polypropylene(PP) and Nylon66 matrix composites with surface treated CNFs(vapor grown carbon nanotubes:VGNFs and vapor grown carbon fibers:VGCFs). Fillers prepared in wet process are aluminate coupling VGNFs(Al–VGNFs),oxidation VGNFs(o–VGNFs), and amino–functionalization VGNFs(a–VGNFs). Fillers prepared in dry process are acetylene–plasma coating VGNFs and VGCFs(C2H2–VGNFs,VGCFs). Raman and FTIR spectra indicate that amino groups formed on the VGNFs in amino–functionalization. And methyl, methylene, and carboxylic groups are contained in the VGCFs by plasma coating. Granular film is observed on the CNFs surface by SEM and TEM. Matrix composites were obtained by twin screw kneader, and specimens were fabricated by injection molding. The tensile strength of PP matrix composites with Al–VGNF and a–VGNF are 10% higher than those of PP with VGNF. The Young′s modulus of Nylon66 matrix composites increased sligtly by all the treatments, but the tensile strength and the fracture strain are improved by only an aluminate coupling agent. Adding C2H2–VGCFs improved Young′s modulus and tensile strength of PP composites despite low coverage and addition volume.
