Evaluating the influence of contacting fluids on polyethylene using acoustic emissions analysis

Identifying microstructural changes related to solvent effects in their early stages to prevent mechanical losses in polymers may be crucial, especially for applications where a leak is hazardous, as in fuel piping and storage tanks. Acoustic Emissions (AE) testing has proven to be a valuable tool for monitoring material failure, though mostly until now for composite systems. The present study examines the use of AE techniques to monitor and characterize the effects of two different chemical agents (i.e. an aqueous detergent and toluene) on the structure of a semi-crystalline polymer (high density polyethylene, HDPE) over different periods of exposure. Characterization of the aged polymer by tensile testing and X-ray diffraction was correlated with the signal-based and parameter-based analysis of AE information. Results presented reinforce the use of AE testing as a promising technique for understanding structural changes in polymers.