Vibrating Rod Viscometer: A Valuable Probe into Polyurethane Chemistry

Abstract

The vibrating rod viscometer has been used to examine the rheology of reacting slabstock foam formulations. The reaction can be divided into three rheological domains. The first begins during mixing of the reagents and continues up to the point immediately prior to cell opening. This region is completely dominated by a reduction in the system's viscosity caused by the increase in the temperature of the reaction. During this stage of the reaction, the molecular weight increase from the urethane reaction has not proceeded sufficiently to cause a measurable increase in viscosity. Interestingly, the system's viscosity is also unaffected by the weakly interacting monodentate urea segments observed by infrared spectroscopy during the latter part of this stage of the reaction