Rheological Behavior of Recycled Plastics, Blends and Composites

Rheological properties are useful in evaluating materials performance during processing operations. Rheology is a sensitive tool in identifying and/or detecting any microstructural changes that is directly related to mechanical properties of the final products. In order for polymer wastes to be reprocessed in standard plastics equipment and produce high yields of molded and film products, the rheological properties must first be understood. Recent development in the green polymer composite has attracted a significant interest to sustain the ecological friendliness of the Recycled poly(ethylene terephthalate):rPET (rPET) and recycled poly(propylene) (rPP) blend. The common problem during polymer recycling is the degradation of the polymer that leads to the reduction of its molecular weight (Mw). Reprocessing at high temperatures with thermal exposure, shear as well as the presence of moisture and physical contaminants (poly(ethylene) (PE), poly(vinyl chloride) (PVC, adhesives) lead to a remarkable Mw” loss. This chapter presents an overview of rheological properties of plastic waste blends and composites. It mainly focuses on rPET and rPP and natural fibers composites of recycled polymer.