Thermal degradation kinetics of bio-based polyurethanes assisted by model-free kinetics and kinetic modelling

Description

Polyurethane (PUR) foams find application as a thermal insulating material in buildings, furniture, and
transportation. One of the precursors to synthesize PUR are polyols and these are produced mainly from fossil
fuels. Producing polymers using fossil fuels not only hampers the efforts being made in reducing our dependency
on non-renewable sources but also contributes towards polluting the environment, climate change and global
warming. In our project, we work with polyols produced from biomass, however just making bio-based PUR is not
enough, also their thermal insulation and flame retardancy properties should be comparable to the commercially
available products. As high flammability and fast spread of flame in the course of fire are highly undesirable in
these applications, there is an emphasis on studying the thermal and thermo-oxidative degradation of PUR in the
absence and presence of flame retardants, also including the study of the emission of volatile gases that fuel the
combustion [1].
The performance of our bio-based polymers is compared with conventional fossil fuel-based products by
comparing their thermal degradation behaviour. This is facilitated by using TGA under diverse temperature
programmes and atmospheric conditions and studying in detail the degradation products formed, including
residues or char and evolved gases using spectroscopic techniques. Specifically, TGA-MS for simultaneous
evolved gas analysis and FTIR spectroscopy for the analysis of residues at different instances in the degradation
process. Going one step further we also build reaction models using the data obtained from TGA, TG-MS and
FTIR. TGA data obtained under different atmospheres and for different temperature programs, were kinetically
analysed by applying model-free kinetics (MFK), providing information for the development of a more
comprehensive degradation kinetics model [2].
Studying degradation mechanisms and developing composition-based thermal degradation kinetic models will
facilitate predicting the degradation behaviour of PUR of different compositions under a range of conditions.
These models can help to predict the burning speed of PUR not produced yet, which will support developing even
better bio-based PUR compositions, while saving a large amount of time and materials.
References
[1] S. Duquesne, M. Le Bras, S. Bourbigot, R. Delobel, G. Camino, B. Eling, C. Lindsay, and T. Roles. Thermal
degradation of polyurethane and polyurethane/expandable graphite coatings. J. Polym. Degrad. Stab., 74(3)
(2001) 493–499; [2] S. Vyazovkin, A. K. Burnham, J. M. Criado, L. A. Pérez-Maqueda, C. Popescu, and N.
Sbirrazzuoli. ICTAC Kinetics Committee recommendations for performing kinetic computations on thermal
analysis data. J. Thermochim. Acta., 520(1-2) (2011) 1–19
Acknowledgments
POLYFLAM project, FYSC, MACH

Period	9 Nov 2021
Event title	Brightlands Polymer Days 2021: Innovative Polymer Materials for a Sustainable Future
Event type	Conference
Location	Eindhoven, Netherlands
Degree of Recognition	International