Thermal Volatilization Analysis: A Versatile Platform for Spectroscopic Investigations of Polymer Degradation Processes

Abstract

The thermal volatilization analysis (TVA) and subambient thermal volatilization analysis (SATVA) techniques are described. In addition to rate profiling of the volatile product flux of thermal degradation under high-vacuum conditions through measurement of pressure in the vacuum line as a function of sample temperature, the TVA technique is shown to afford a convenient method for an isolation, on the basis of volatility under high-vacuum conditions, of product fractions of thermal degradation for subsequent spectroscopic analysis. The capacity and flexibility of TVA as a platform for these analyses are illustrated in a case study format by degrading poly(bisphenol A, 2-hydroxy propylether). The overall degradation process is quantified, and most significant pathways of thermolysis are identified through subsequent spectroscopic analysis of products of decomposition. The design and construction of a modified vacuum-tight long-path gas IR cell, as an interface allowing for the application of Fourier transform infrared spectroscopy (FT-IR) for the on-line analysis of volatile products of polymer degradation, is detailed. Proof of concept and application of this new analytical technique, subsequently referred to as TVA/FT-IR, is illustrated through the examination of appropriate aspects of the thermal degradation of polymethyl methacrylate polymers.