a	mass coefficient
A	pre-exponential factor
DTG	derivative thermogravimetry
EPS	expandable polystyrene
E	activation energy
FTIR	Fourier transform infrared
g	gene
GA	genetic algorithm
IS	isocyanate segment
MLR	mass loss rate
PU	polyurethane
PUs	polyurethanes
PUF	polyurethane foam
Py-GC/MS	pyrolysis-gas chromatography/mass spectrometry
RPUs	rigid polyurethanes
t	time
T	temperature
TG	thermogravimetry
TG-MS	TG-mass spectrometry
Tp	peak temperature
UB	urethane bond
XPS	extruded polystyrene
α	conversion percent
β	heating rate