Poly(hydroxyurethane)s with diethyl tartrate-based amide backbone by an isocyanate-free route: Use as adhesives

Non-isocyanate poly (hydroxyurethanes)s (PHUs) are important green alternatives to conventional polyurethanes. This work focuses on the synthesis of novel PHUs with an amide backbone and the study of the properties of PHUs regarding their potential use as hot-melt adhesive. PHUs were synthesized by a solvent-free and catalyst-free method from bis(2,3-dihydroxypropyl)ether dicarbonate and 1,3diaminopropane using various molar ratios of diethyl tartrate. The polymers were properly characterized by FT-IR, H-1 NMR and C-13 NMR spectroscopy and the TGA and DSC analyses were performed. Rheological and mechanical properties are also presented. The work of adhesion and mechanical properties were determined. PHUs with diethyl tartrate-based amide backbone revealed improved thermal stability over conventional PHUs. The addition of diethyl tartrate increased the hydrophobicity of coatings by increasing the water contact angle and decreasing the polar component of surface free energy of PHU coatings. Furthermore, the mechanical properties of PHUs with addition of diethyl tartrate were noticeably improved. (C) 2018 Elsevier Ltd. All rights reserved.