Molecular Modification and Compatibilization of Collected Polyethylene

The increasing use of plastics in packaging materials leads to growing amounts of plastic waste. Recycling material is generally regarded as advantageous. But in fact very few products are made from plastic waste, partly this can be explained by that little is known about the recycling process and the properties of collected materials. There is a need for injection moulding grades of recycled polyethylene, while large amounts of extrusion grades are available from packaging waste. A controlled way of de-branching or partly degrading PE would be desirable. Peroxides are commonly used to crosslink polyolefins, but under certain conditions a chain scission reaction occur. Another problem encountered with recycling of polyethylene are the poor miscibility of low amounts contaminations, i. e. polypropylene. A compatibilizer can improve properties of such polymer blends, in this work EPDM is used as compatibilzer. Studies of mechanical properties and viscosity measurements show that it is possible to partly degrade PE with peroxide exposing it to high temperature and oxygen. The properties of PE/PP blends were improved with EPDM as compatibilizer.