Effect of fillers on the properties of recycled polymers

The main problems in post-consumer plastics recycling are due to the degradation undergone during lifetime and during processing steps. Moreover, for heterogeneous recycling, the incompatibility among the different polymeric phases give rise to secondary materials with low mechanical and thermomechanical properties. The properties-reprocessing relationships are an important tool for determining not only the properties of the recycled polymers but also the strategies to apply (processing conditions, stabilisers, fillers, compatibilizers, etc) in order to obtain recycled polymers with good mechanical properties. In this work the effect of adding inert fillers and modifier agents to recycled post-consumer plastic materials is discussed. The addition of inert fillers of different nature can strongly improve the rigidity and thermomechanical resistance of these secondary materials. The addition of modifier agents improves the deformability and the impact strength of the recycled plastics. The beneficial effect of inert fillers and modifier agents is particularly important in the case of commingled post-consumer plastics.