Environmental Effects on the Dimensional Stability of Polymeric Glasses: Small Molecule Plasticizers

Texas Tech University, Lubbock TX

Investigators

Abstract

Novel experiments involving relative humidity-jumps (RH-jump) and carbon dioxide pressure-jumps (PCO2-jump) will be performed to investigate the structural recovery and physical aging responses of polymers subjected to rapid changes in plasticizing environment and chemical activity. The effects of PH or PCO2-jumps will be compared quantitatively to those induced by temperature-jumps. The comparisons will test the underlying hypothesis that changes in plasticizer content are quantitatively similar to changes in temperature for glass-changes in plasticizer content are quantitatively similar to changes in temperature for glass-forming systems. The classic TNM-KAHR models of aging and structural recovery will be extended to include plasticizer effects and compared quantitatively with the experimental data. Modern uses of plastics demand that they show dimensional stability and moisture resistance for both short and long time durations. Electronic, automotive and infrastructure applications demand increasingly sophisticated data and model of the impact of plasticizing molecules such as water and carbon dioxide on the performance of polymers. The proposed work may provide unique and fundamental data that tests the validity of models used to describe the mechanical and dimensional behavior of plastics in such environments.