Use of carboxymethyl cellulose in polyurethane synthesis for thermal applications

This research utilizes carboxymethyl cellulose (CMC) as a renewable feedstock in polyurethane synthesis, offering improved thermal stability and potential for biomedical applications. In this study, a series of CMC-based polyurethanes was synthesized by using a step-growth polymerization reaction. The initial step involved the reaction of isophorone diisocyanate (IPDI) with hydroxy-terminated polybutadiene (HTPB) to prepare an isocyanate (-NCO) terminated prepolymer. Then, this prepolymer was extended using a combination of chain extenders, namely 1,4-butanediol and CMC, to produce the final polyurethanes. Five different samples of polyurethanes were prepared using varying mole ratios of chain extenders (CMC and 1,4-butanediol). The developed polyurethanes were characterized through Fourier transform infrared (FTIR) spectroscopy and proton nuclear resonance (1H NMR). The thermal degradation behaviour of the CMC-based polyurethanes was observed by using thermogravimetric analysis (TGA), while the molecular weight of the samples was determined by using Gel permeation chromatography (GPC). The results showed that polyurethanes prepared using CMC as a natural chain extender, in place of petrochemical-derived 1,4-butanediol, exhibited improved thermal stability and higher molecular weights. Notably, MWF-5 exhibited the highest tensile strength and breaking strain among all the samples, while MWF-1 showed the lowest values.