BY Andreas Holländer
Many product properties of plastics result from the fact that technical polymer materials are a complex mixture of different molecules. The chains of polymer molecules have a certain length distribution and contain irregular structures. The prop- erties of technical materials are often modified by copolymerization, by blending, and by adding additives. This formidable complexity of real world polymer materials gives rise to very different aging processes ranging from the simple loss of one of the ingredients to alterations in the chemical structure of one or more components. Different materials can have different aging pathways, even if they appear to be very similar. The knowledge about the degradation mechanisms allows us to define strategies for the preservation of properties and the possibility for the repair of aging effects. Beside general rules and approaches, the specificity of a particular material has to be taken into account. In the paper, examples are discussed to il- lustrate this situation. While some of the procedures seem to be straight-forward, more research is required to make others work.