(130d) Extrusion Foaming of Cellulose Fiber Reinforced Polypropylene Composites

The paper investigates the effect of fiber content on foaming behaviour of cellulose fiber reinforced polypropylene composites in extrusion. Two types of polypropylene (linear and branched structures) are used as a polymer matrix. Cellulose fibre, polypropylene, and maleated polypropylene are melt-blended using a twin-screw extruder. Thermal behavior of the composites was characterized by a differential scanning calorimeter (DSC) while the viscosity of the composites is evaluated by a rotational and extensional rheometer. Foaming behaviour of the composites is examined using an extrusion foaming system, in which a blowing agent used is a physical blowing agent. Foam density and cell density are characterized for the foamed composites. We discuss the effects of molecular structure of polypropylene and fiber content on foaming behaviour of the composites as well as thermal and rehological properties.