A test method to evaluate the viscoelastic properties of pressure sensitive adhesives using a texture analyzer

A test method employing the Texture Analyzer was developed to evaluate the viscoelastic properties of pressure-sensitive adhesives. Dynamic testing of coated substrates was performed using the “cycle until count” mode and measurement of compression force. The available frequencies were 1 to 7 Hz, and the strain and temperature were varied from 0 to 25% and −10 to 120°C, respectively. Adhesive-substrate interactions were examined for several substrates. Results were assessed using single point data, Lissajou figures (stress-strain curves), and derived dynamic mechanical properties. Time-temperature superposition curves were developed from the single point data. Lissajou figures facilitated examination of adhesive hysteresis at various test conditions. Since the “cycle until count” mode effectively imposed a sinusoidal strain on the adhesive sample, the storage and loss moduli generated with new method was compared with dynamic mechanical properties obtained from conventional oscillatory shear.