Waste cooking oil-based polyurethane solid polymer electrolyte : The effect of isocyanate structure / Nor Azmiera Kamarulzaman

Waste cooking oil-based polyurethane was prepared via solvent-free method
using waste cooking oil based polyol (WCO-p) and 4,4- diphenylmethane
diisocyanate (MDI) or 1,6- hexamethylene diisocyanate (HDI) with lithium
trifluoromethane sulfomide (LiTFSI) salt and ethylene carbonate (EC) as
plasticizer. The polyurethane films were examined using Fourier Transform
Infrared Spectroscopy (FTIR) and Electrochemical Impedance (EIS),
Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD).
The ionic conductivity from EIS result of the polyurethane film mixed with
MDI and salt are higher which is 5.76 x10-6 Scm-1compared to film mixed
with HDI and salt 6.03 x10-7 Scm-I. This was proved by XRD analysis
which is more amorphous than PU-HDls. However the glass transition is
highest temperature due to sterlc hindrance of benzene ring in hard segment
for PU-MDls. FTIR analysis showed the absence of the band in the range of
2260 to 2310 cm-I proves there is no free NCO group that confirms the
urethane reaction is complete in the structure of polymer. However that
band is presence at 2276.05 cm-I in PU-MDI spectrum showed not all of the
isocyanate groups reacted during polymerization.