Dynamic mechanical properties of titanium dioxide‐filled poly(vinyl acetate) at 0–40°C.

Abstract

Abstract The dynamic mechanical properties of titanium dioxide‐filled poly(vinyl acetate) have been studied at filler concentrations of 0, 10, 20, 30, and 40 wt.‐% TiO 2 by using a torsional pendulum. The damping factor was found to increase with higher temperatures. At 40°C., the damping factors for the different TiO 2 concentrations were estimated to be the same. Damping factors above 40°C. were difficult to obtain due to the rubbery nature of the TiO 2 –poly(vinyl acetate) systems. From 24 to 35°C., 10 wt.‐% TiO 2 ‐poly(vinyl acetate) was closer in damping factor increase to unfilled poly(vinyl acetate) than to the higher TiO 2 ‐content polymers. At all temperatures, damping factors decreased with higher TiO 2 concentration. As the temperature decreased to 0°C., damping factors for the filled systems approached a common value. Potential energy of filled systems as indicated by shear modulus values is increased by higher TiO 2 concentrations and lower temperature. Kinetic energy for the filled systems, as shown by the out‐of‐phase modulus, is actually increased by larger filler concentration and higher temperature. A model is proposed where introduction of TiO 2 filler acts to increase general long‐range polymer chain stiffening and at the same time enables short‐range chain mobility to rise, possibly through greater side‐chain motion.