Process Control of Loss Factor in Soft Materials

Abstract

Loss tangent defined by the ratio of loss modulus to storage modulus, G”/G’, is widely used as a measure of energy loss for rubber materials. We can expect high loss tangent due to unstable state of polymer chains in large deformation. However, chemical cross-linking is usually introduced in no deformation where we cannot expect high loss tangent. Even if introduced in deformed state, polymer chains take relaxation before completion of cross-linking. In this study, hence, a novel two-step cure has been proposed. The loss tangent by two-step cure has been found to be higher than that by one-step cure in no deformation, showing effectiveness of the process proposed.