Rheological Studies of UV - curable Materials

The challenge for studying fast changing systems with rheology such as UV initiated polymerization and crosslinking is multifold. These materials react within seconds and the moduli change over 2 to 3 decades. UV light must irradiate the sample homogeneously over a short time period and fast data acquisition is required to capture the modulus change during the reaction. An option for UV curing, using parallel plate has been designed for the ARES rheometer. A fast data sampling device with a new correlator has been developed to provide up to 500 dynamic mechanical data points per second, so the modulus build up can be easily followed. Results are obtained for an acrylate-based pressure sensitive adhesive. The curing reaction is studied as a function of the sample gap, UV intensity and UV exposure time.