AGD Surface Modification on Nanofibers to Improve Dispersion and Interfacial Bonding
Abstract
Vapor grown carbon fibers (VGCF) were plasma treated before added to PP "propylene" and epoxy, respectively, in an attempt to improve the fiber's dispersion and interfacial bonding with the matrix. To disperse VGCF within PP, Hexamethyl-disiloxane was used to coat the fibers and to disperse VGCF within epoxy, the VGCF's were surface grafted with hydrophilic property that is most compatible with epoxy. For the case with PP, the dispersion of nanofibers was carried out by solution blending, mechanical mixing, and sonication. Levels of 4% - 31% volume content of VGCFs were mixed with polypropylene "PP" powder, and then were melt-mixed using a twin-screw extruder in order to align the fibers. For the further alignment of fibers, extruded rods obtained by twin screw extruder were stacked in the mold cavity for the compression molding. In the case of 31% volume content, the tensile modulus and strength were improved by 100% and 40%, respectively, and the flexural modulus and strength were increased by 120% and 25%, respectively. The shear modulus showed 65% increase, but the strength dropped sharply by 40%. In the transverse direction, the tensile, flexural, and shear strength decreased as more fibers were added. The matrix modification by maleic anhydride (MAPP) increased the tensile and flexural properties of VGCF/PP by 20% - 30% in the longitudinal direction, and 40% - 250% increase in the transverse direction. The fiber surface treatment by plasma improved tensile and flexural properties of untreated VGCF/PP "18 % vol" composites by 10% - 30% in the longitudinal direction, but strength in the transverse direction decreased by 30% - 40%. For the case with epoxy, the dispersion of nanofibers was also carried out by solution blending, mechanical mixing, and sonication. Levels of 1 - 7wt% content of VGCFs were mixed within epoxy. The Atmospheric Plasma Treated "APT VGCF's had much higher adhesive strength with epoxy matrix than ran VGCF's.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 26, 2007
- Accession Number
- ADA473067
Entities
People
- Byung-sun Kim