Computational study of thermally controlled polymer network disassembly via the incorporation of sterically hindered urea linkages

Previously, our work was focused on the experimental details of the controlled thermally decrosslinking behavior of a polymer system that contained sterically hindered urea linkages. Such systems are of interest because they introduce rework capabilities into the polymeric material. The focus of this paper is to study these controllable decrosslinking systems from a theoretical perspective. In this study, computational methods were used to study the 2-(tert-butylamino)ethyl methacrylate-isophorone diisocyanate-2-(tert-butylamino)ethyl methacrylate polymer system that has been shown to undergo controlled thermal network disassembly. The following two aspects are the focus of this investigation. First, computational methods were used to suggest other structures within this family of compounds that might also be reworkable. Based on the simulation data likely candidates are suggested and the thermal decrosslinking properties are hypothesized compared with the real system that was experimentally studied. Second, heat of reaction data was determined from simulations of the decrosslinking reactions. These data were then compared with the experimental data and a predictive model was developed to estimate the decrosslinking temperature of the polymer network when exposed to a particular severing agent. (C) 2002 Elsevier Science Ltd. All rights reserved.