Mechanical behaviour of a plasticized PVC subjected to ethanol exposure

Abstract

This paper presents the results of a series of experimental investigations conducted to assess the influence of ethanol exposure at different concentrations on the mechanical properties of a plasticized PVC membrane. Exposure to pure ethanol resulted in a reduction in flexibility, or embrittlement, and the transformation of the PVC membrane from a flexible material capable of undergoing large strain hyperelastic behaviour to a stiffer material with pronounced yield behaviour. Results of X-ray fluorescence measurements indicate the loss of the plasticizer from the PVC membrane as a contributing factor for the alteration in the mechanical properties of the PVC membrane. The experiments also indicate a slower rate of plasticizer leaching during exposure to lower concentrations of ethanol. Exposure of the PVC membranes to 80% and 50% concentrations of ethanol and pure water has a reduced influence on the loss of large strain deformability of the PVC membrane, even after more than one year of exposure. The PVC membranes exposed to a mixture of ethanol and pure water in equal volume proportions indicate that, after longer period, the PVC membranes became softer and exhibit greater deformation under the same external load. This phenomenon can be attributed to the swelling of the PVC membrane.