Abstract
The two-component system of poly (vinyl nitrate) and poly (methyl acrylate) was examined by the measurement of temperature dispersion of dynamic mechanical loss with torsion pendulum. A convertible change between single-peak state and double-peak state was observed in the dynamic mechanical properties of the system. It was tentatively supposed that the former is a uniform state and the latter is a two-phase state, and the phase diagram of this system has a lower critical solution temperature (LCST). From the observation of the thermal behavior of the sample in the two-phase state prepared by rapid quenching, the conversion rate from the two-phase state to the uniform state was determined at various temperatures. The apparent activation energy for this phase transition process was about 40 kcal/mol, which is nearly equal to that of segmental motionaround Tg of vinyl polymers.
