A computational and comparative study of two controllable dissembling polymer networks

摘要

Previously, our work reported the experimental details of the thermally controlled decrosslinking behaviour of a polymer network comprised of 2-(tert-butylamino)ethyl methacrylate-isophorone diisocyanate polypropylene oxide 725-isophorone diisocya-nate-2-(tert-butylamino)ethyl methacrylate (t-BAEM-IPDI-PPO_(725)-IPDI-t-BAEM). Such systems are of interest because they introduce rework capabilities into a polymeric material. In this study, computational methods were used to study the disassembly process. Heats of reaction data were determined from simulations of the decrosslinking reactions. These data were then compared to the experimental data and a predictive model developed to estimate the decrosslinking temperature of the polymer network when exposed to a particular severing agent. This system was then compared to another thermally decrosslinking system 2-(tert-butyla-mino)ethy] methacrylate-isophorone diisocyanate-2-(tert-butylamino)ethyl methacrylate (t-BAEM-IPDI-t-BAEM), which is the shorter chain analogue of t-BAEM-IPDI-PPO_(725)-IPDI-t-BAEM. The introduction of the polymer chain into the disassembling crosslinker was found to lower the disassembly temperature when exposed to the same degradation conditions.