Using Experimental Interpolymers to Upgrade Mechanical Properties of Recycled Thermoplastics

摘要

The aim of this work was to evaluate routes to upgrade recycled automotive engineering plastics, principally thermoplastic polyolefin (TPO) and polypropylene (PP). Recycled automotive plastics have been collected in significant volumes, but these materials are not recycled as they often do not maintain the desired specifications demanded from the corresponding virgin resins. The plastic may either be contaminated by other plastics or coating materials, or have deteriorated during the service life or during reprocessing. An experimental line of both the ethylene-styrene interpolymers (ESI) and the ethylene-propylene-styrene interpolymers (EPS) were used to successfully improve the impact strength of recycled TPO and recycled PP from the automotive industry. Similar results were seen after the addition of Nordel~R ethylene-propylene elastomer (EPDM). The stiffness of these recycled blends of engineering polyolefin thermoplastics and interpolymers was reduced. The reduction in stiffness may be compensated for by the addition of filler to the system. Optimised formulations may be blended to meet desired specifications. We show how the experimental interpolymers, which possess a good affinity for inorganic filler, are ideal for both improving the impact strength and polymer/filler interfacial strength. Tensile mechanical properties and dynamic mechanical properties of the blends were used to help optimise the formulation.