Venkata S. Chevali

Processing and characterization of a polypropylene biocomposite compounded with maleated and acrylated compatibilizers

Polypropylene (PP) biocomposites containing 20 wt.% sunflower hull as a particulate reinforcement were compounded and tested under tensile, flexural, and impact loadings. The incorporation of the sunflower hull without compatibilizer resulted in diminished tensile strength and impact energy absorption but increased flexural strength and both tensile modulus and flexural modulus when compared to neat PP. Formulations containing three different chemical compatibilizers were tested to determine their effectiveness in improving the interfacial adhesion between the fiber surface and PP chains. Maleic anhydride grafted with PP (MA-g-PP) achieved greater improvements in tensile strength but reduced impact strength in comparison to an acrylic-acid-grafted PP compatibilizer (AA-g-PP). The molecular weight, graft level, and the ability to affect strength, modulus, and absorbed impact energy were also investigated for the compatibilizers. A MA-g-PP having high molecular weight and low graft level was most effective in improving the investigated properties of a sunflower hull-reinforced polypropylene biocomposite.

Mechanical Properties of Hybrid Lignocellulosic Fiber-Filled Acrylonitrile Butadiene Styrene (ABS) Biocomposites

Biocomposites compounded using acrylonitrile butadiene styrene with sunflower hull and distillers’ dried grains with soluble fibers were analyzed for their effectiveness in hybrid form to understand the combined effect of two fillers. The thermal and mechanical properties of the 20 wt.% fiber hybrid biocomposites were compared against the neat polymer. The biocomposites were processed using twin screw extrusion and injection molded as ASTM test specimens. The hybrid biocomposites showed marginal variations in thermal and physical properties, and showed near equivalent mechanical properties. The thermal and structural properties were attributed to the nonstructural and structural constituents of the fibers, respectively. GRAPHICAL ABSTRACT