Das Verhalten von PVC hart gegen Chemikalieneinwirkung

Behaviour of Unplasticized PVC under Chemical Attack After a general view on the mechanism of chemical attacks to plastic materials, the most important effects to the chemical resistance of unplasticized PVC will be described. The test methods for the determination of chemical resistance are explained, basing on the historical development over 50 years time and the evidence of information. With the aid of some characteristic examples the various mechanism of attack and their influence on uplasticized PVC are described both for immersiontest as well as for long term internal pressure tests and it is shown, that both tests complete each other. A proposal is made for the determination of chemical resistance factors f_CR of unplasticized PVC basing on long term internal pressure tests with acceptable testing times. In consideration of the results of immersion tests it will be possible to give f_CR factors for rigid PVC too, without being forced to wait for the abrupt drop of the characteristic creep strength curve, which is not yet reached after 10⁵ hours, with water at 60 degr. C.