Water dispersed bio-derived transparent polyurethane: Synthesis, properties including chemical resistance, UV-aging, and biodegradability

The present work demonstrates the fabrication of water dispersed bio-derived transparent polyurethane (WBPU) using different bio-derived precursors including PEG-600, dimer acid, castor oil, and glycerol. Three different compositions of WBPU were prepared by varying the amount of 1, 4-butanediol (BD), isophorone diisocyanate (IPDI), and glycerol-dimer acid modified citric acid based polyol. Different techniques including FTIR, XRD, 1H NMR, and 13C NMR were conducted to sanguine the successful synthesis of the WBPUs. Moreover, specific gravity, mechanical property measurements as well as GPC, TGA, and DSC studies were performed to get detail idea about the physical, mechanical, and thermal properties of the as-synthesized WBPUs. DLS was executed to check the particle sizes and stabilities of the as-prepared WBPUs in the dispersion medium. The as-prepared WBPUs have high weight-average molecular weight (Mw, 33,260−41,660 g/mol) and number-average molecular weight (Mn, 31,579−37,803 g/mol). They have specific gravities of ∼1.19−1.32. All WBPUs showed good toughness (∼26.7–27.6 MJ/m3), very high elongation at break (∼2544−3027%), high impact resistances (∼9.42−10.33 kJ/m), proficient adhesive strengths (∼7.19−8.09 kPa for wood and ∼5.33−6.16 kPa for metal) and good chemical resistance in different media. Moreover, the as-prepared WBPU exhibits not only high UV-aging capability but also proficient biodegradability. The WBPUs were successfully prepared through a sustainable route and those can be utilized as surface coating material.