Development of Computer-Controlled Thermogravimetric Instrumentation for Measurement of Environmental and High Temperature Volatilization and Desorption of Contaminants from Polymeric Materials.

A conventional thermogravimetric analyzer was modified and computerized to provide an environmental chamber adequate for comparative measurement of diffusion and evaporation of liquids from polymers. The computer-instrument system supplements complex and expensive environmental wind tunnel research for preliminary measurements of relative rates of processes at both environmental and high temperatures and under atmospheric conditions. The diffusion and evaporation transport properties of liquid-state chloroesters, diesters, organophosphates, and ether-acetates were measured in or on urethane, polyester, and methacrylate polymers. The results obtained that are of general interest to computer-oriented chemists demonstrate the enhancement of instrument performance by the computer system the important system components are signal analysis software, kinetic computations, graphic display of rate data, and data base generation. In addition, correlations of physical and solvent properties with transport rates would be of interest to polymer and environmental chemists. The system consists of a number of modular hardware and software subsystems that can be adapted by other investigators to obtain desired capabilities.