Experimental Investigation of Destructive and Non-Destructive Properties for Thermosetting and Thermoplastic Polymers

This experimental work aims at the study by non-destructive and destructive testing of the mechanical and acoustical properties of cold-setting epoxy resins plasticized with amounts of plasticizer and of PMMA (Plexiglas), both belonging to the two basic categories (thermosetting and thermoplastics respectively) of polymeric materials, which usually can be modified because of polymerization rate and curing, change in temperature and frequency, by the addition of plasticizers and/or inclusions as well as due to discontinuities (defects, voids and porosity) where stress concentration exists. On the other hand, ultrasound is a mechanical, elastic wave of very high frequency, and can be used for material testing. Using ultrasounds, defects, discontinuities, and damage can be detected, and moduli can be evaluated accurately. It should be noted that the moduli determined in this way are the dynamic moduli and differ from the static ones for any material. Here, the authors focus their study on plasticized epoxy resins and PMMA and apply this NDT method to estimate mechanical properties and correlate the results with those from destructive tests. Finally, the glass-transition temperature of plasticized epoxies was also evaluated from thermal experiments to determine the effect of the plasticizer.