Advanced Blister Test with Predefined Area

Abstract

An advanced blister test using a predefined blister area is employed to determine the adhesion strength (energy release rate) as well as characterize the flexural modulus of polymer material. The predefined blister area allows for a low adhesion precrack area, defining an initial constant blister area and the modulus determined from each experiment negates the effect of uncertainties associated with the polymer modulus. Ideal specimens with epoxy coatings of various thickness are analyzed using the proposed setup. After measuring the properties at time zero the coatings are subjected to accelerated testing conditions (high temperature/ humidity storage) and the degradations of the coating properties are documented. The modulus increases significantly after thermal aging but the adhesion strength is determined accurately by accounting for the effect of the modulus quantitatively.