Processing and mechanical properties of thermoplastic composites based on cellulose fibers and ethylene-acrylic acid copolymer

The melt processing and the tensile mechanical properties of composites consisting of 30 wt% softwood kraft pulp cellulose fibers and ethylene-acrylic acid copolymer (EAA) with 7% acrylic acid content were studied. The compounding techniques used were extrusion mixing performed with a single screw extruder and elongation dispersive mixing performed with the injection-molding machine. All blends were injection-molded in a final step. Fiber length, fiber content, and mechanical properties were measured and the number and the size of the fiber aggregates were determined by microscopy analysis. It was concluded that two passes of elongation dispersive mixing had a beneficial effect on the mechanical properties, which could be related to the fewer and smaller amounts of aggregates. The different types of processing performed had a small or insignificant effect on the fiber length since the fiber lengths measured were within the same range as that of the starting material. POLYM. ENG. SCI., 52:19511957, 2012. (c) 2012 Society of Plastics Engineers