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Significant strides in the development of non-isocyanate polyurethane (NIPU) have been made in the coatings industry. Aligned with green chemistry principles, this study explores the use of bio-based, low volatile organic compounds and fast-curing waterborne NIPU for coating applications. The linseed oil-based cyclic carbonate was synthesized via a thiol–ene click reaction and was followed by an esterification reaction directly from linseed oil. In this structure, the cyclic carbonates are introduced as pendant functional groups to accelerate the curing. Next, a series of linseed oil-based waterborne NIPUs were synthesized and developed from the linseed oil-based cyclic carbonate, a bio-based fatty acid diamine, and an internal dispersion agent. Different formulations of the linseed oil-based NIPU coatings were designed by varying the internal dispersion agent content and urethane content, and a solvent-borne NIPU was included in the study for comparison purposes. The NIPU coatings with different formulations achieved a broad range of thermal stabilities, viscoelastic properties, and mechanical properties. The general coating properties—including hardness, solvent resistance, impact resistance, and adhesion—were evaluated to demonstrate the practical application of the waterborne NIPU in coatings. The linseed oil-based waterborne NIPU coatings exhibited performance comparable to both a solvent-borne NIPU coating and a commercial waterborne isocyanate-based polyurethane coating. [ABSTRACT FROM AUTHOR]

The coatings industry is increasingly aware of the need to protect the environment and is constantly striving to ensure the safety of the industry and the health of consumers, which creates demand for environmentally friendly non-isocyanate polyurethanes (NIPU). In this study, the waterborne NIPU epoxy hybrid coatings were prepared from waterborne amine-terminated NIPU and waterborne epoxy chain extender. The waterborne amine-terminated NIPU were derived from diglycerol dicarbonate, 3,3′-diamino-N-methyldipropylamine, and fatty acid diamine (FDA). The waterborne epoxy chain extender was synthesized from diethanolamine and trimethylolpropane triglycidyl ether. The Fourier transform infrared spectroscopy and nuclear magnetic resonance were applied to confirm the chemical structure of synthesized materials. The effect of the soft/hard segment on waterborne NIPU epoxy hybrid coatings was studied by differential scanning calorimetry, thermogravimetric analysis, and tensile tests. Two glass transition temperatures were found in the samples with the largest amount of FDA while only one glass transition temperature was found on the other two samples. The thermal stability was enhanced by incorporating a higher amount of FDA. Finally, Young's modulus and tensile strength decreased with an increasing amount of soft segment and elongation-at-break was increased as expected. In general, this work explored the method for preparing waterborne non-isocyanate polyurethane epoxy hybrid coatings, which could reveal similar soft/hard segment performance with conventional isocyanate-based waterborne polyurethane. [ABSTRACT FROM AUTHOR]

Non-isocyanate polyurethanes (NIPU) attract more attention these days due to the increasing environmental concerns from the traditional polyurethanes that involve isocyanates in the synthesis. Herein we prepared a novel one-package (1 K) waterborne non-isocyanate polyurethane in this study. A series of 1 K waterborne epoxy hybrid coatings were synthesized from bio-based amine, cyclic carbonate, internal emulsifier, and epoxy resin. Different formulations of the 1 K waterborne NIPU epoxy hybrid coatings were designed including different ratios of soft and hard segments, different urethane contents, and different functionalities and structures of the hybridized epoxy. The chemical structure of the NIPU polymers was analyzed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The thermal stability and mechanical property of the 1 K waterborne NIPU coatings were investigated by thermogravimetric analysis and tensile tests, respectively. One glass transition temperature studied by differential scanning calorimetry was found for each coating which demonstrated that the soft segments and the hard segments were mixed well in the 1 K waterborne NIPU coating systems. The coatings with different formulations can achieve a broad range of thermal and mechanical properties. In addition, the general coating properties, such as hardness, adhesion, and chemical resistance, were evaluated to demonstrate the practical application of the 1 K waterborne NIPU in coatings. This study proposed a facile method to prepare one-package environmental-friendly waterborne epoxy hybrid non-isocyanate polyurethane coatings. [Display omitted] • 1 K waterborne NIPU epoxy hybrid coatings were successfully synthesized. • One Tg of the coating demonstrated no phase separation of hard and soft segments. • Properties are tunable based on types of epoxy and content of soft/hard segments. [ABSTRACT FROM AUTHOR]

• NIPU coatings exhibit excellent anti-corrosion properties by incorporating TEOS. • Incorporating 5 wt. % of TEOS improves the corrosion resistance of NIPU coatings. • Phase separation is observed in the sample with more than 10 wt. % of TEOS. • Coatings without phase separation show higher corrosion resistance. As people become more aware of the necessity and importance of environment protection and product safety, the environmentally friendly non-isocyanate polyurethane (NIPU) has received great attention. In this work, a series of NIPU anti-corrosion coatings were prepared by amine-terminated NIPU, tetraethyl orthosilicate (TEOS), and bisphenol A (BPA) epoxy. First, the BPA cyclic carbonate was synthesized from carbon dioxide and BPA epoxy resin. Then, the amine-terminated NIPU was synthesized from BPA cyclic carbonate and fatty acid amine. Next, the NIPU TEOS hybrid coatings were formulated by different amounts of TEOS. The anti-corrosion performance of NIPU TEOS hybrid coatings was evaluated by electrochemical impedance spectroscopy and salt spray. NIPU coating with 5 wt. % of TEOS showed the best anti-corrosion behavior while NIPU coating with 20 wt. % of TEOS exhibited the worst corrosion resistance. The resulting anti-corrosion difference was attributed to the organic/inorganic micro-phase separation, which was confirmed by scanning electron microscopy and energy dispersive X-ray spectroscopy. This study reveals the effect of TEOS on the anti-corrosion performance of environmentally friendly NIPU coatings. [ABSTRACT FROM AUTHOR]