Peter Trubiroha

Polypropylene Numerical Photoageing Simulation by Dose–Response Functions with Respect to Irradiation and Temperature: ViPQuali Project

The aim of the joint project ViPQuali (Virtual Product Qualification) was to describe a component’s ageing behaviour in a given environment, by numerical simulation.

Chemiluminescence Detection: Principles, Chances and Limitations for the Shortening of Weathering Tests

Improvements in the stabilization of polymeric materials mean that the duration of weathering tests increases. At the same time, however, an increasing number of new developments in ever-shorter development cycles brings about greater demands to shorten the test duration. Apart from accelerating the degradation rate by enhancing exposure parameters, another approach to increasing the test throughput consists in using more sensitive means of detecting degradation effects in earlier stages of the degradation process. The degradation process begins on a molecular level before it starts to spread over higher proportions of the polymer. The effect of degradation on the material builds up until macroscopic properties begin to change, either showing an abrupt threshold behavior or a more gradual response to increasing degradation on a molecular level. From a theoretical point of view, a detection of the earlier stages of the degradation process can be expected by switching from the established, more macroscopic properties in the evaluation of effects to more microscopic ones. While both physical processes and chemical reactions contribute to the degradation of materials, chemical reactions usually are more dominant since their effects tend to be irreversible. Within these chemical reactions, oxidation reactions with oxygen usually are of Chapter 21