Understanding polyurethane thermal degradation kinetics assisted by model free kinetics and kinetic modelling

Description

Insulating polyurethane foams are used extensively in furniture, buildings, and automobiles. Studying its thermal degradation and developing degradation kinetic models can help to understand in detail its high flammability and the volatiles produced during its degradation, which fuels its combustion [1].
Prediction of the degradation behaviour and kinetics of PUR networks having different compositions and under diverse heating and atmospheric conditions will be facilitated by developing composition-based thermal degradation kinetic models. A prerequisite to this will be to get a detailed understanding of thermal degradation kinetics of PUR and PUR-derived products like foams, aiming towards the development of a deeper understanding of the relationship between the degradation of the constituting polyols and the PUR networks.
TGA and spectroscopic techniques are used to study the course of degradation and the formation of degradation products like evolved gases, chars, and residue. Polyether based PUR foams and their constituent polyether polyols analysed using TGA revealed relations between their degradation paths. To support this finding Hi-Res™ TGA experiments were performed, which separated the degradation steps. Simultaneous TGA-MS (for evolved gas analysis) and FTIR spectroscopy (for analysing char and intermediate residues) were employed to better understand the degradation steps. Using this approach, a connection can be made between the chemical composition and structure of PURs and their thermal degradation behaviour, which subsequently can be used to tune the degradation behaviour.
Model-free kinetics was performed on the thermal data obtained through TGA measurements under different atmospheric conditions and temperature programmes [2]. This provided the information for the development of a degradation kinetic model, opening the path towards a more generalized mechanistic modelling.

Period	6 Aug 2021
Event title	47th Annual NATAS Conference, 2021
Event type	Conference
Conference number	47