Dispersion of soybean stock-based nanofiber in a plastic matrix

The focus of this work is the study of the dispersion mechanism of soybean stock-based nanofibers in a plastic matrix. The cellulose nanofibers were extracted from soybean stock by chemo-mechanical treatments. These are bundles of cellulose nanofibers with a diameter ranging between 50 and 100 nm and lengths of thousands of nanometers. These nanofibers were characterized by atomic force microscopy and transmission electron microscopy. X-ray diffraction studies showed that the soybean stock nanofibers had a relative percentage crystallinity of about 48%. Selective chemical treatments increased the cellulose content of soybean stock nanofibers from 41 to 61%. The matrix polymers used in this project were poly(vinyl alcohol) (PVA) and polyethylene (PE). The mechanical properties of nanofiber-reinforced PVA film demonstrated a 4- to 5-fold increase in tensile strength, as compared to the untreated fiber-blend-PVA film. One of the problems encountered in the use of nanoreinforcements lies in the difficulty in ensuring good dispersion of the filler in the composite material. Improved dispersion level of nanofibers within a thermoplastic was achieved by adding ethylene-acrylic oligomer emulsion as a dispersant. In the solid phase of nanofiber-blend-PE composites, the compression-molded samples showed that improved mechanical properties were achieved with coated nanofibers. (C) 2006 Society of Chemical Industry.