Establishment of both mechanically robust yet facile healable and recyclable epoxy resin systems are highly desirable and still present significant challenges. Herein, by fully utilizing epoxidized vegetable oils and dithiol...

Non-isocyanate polyurethanes (NIPU) from renewable resource have attracted much attention for significant benefit for sustainable development and green production. However, the low molar mass and poor mechanical properties of NIPU...

Tailoring the performance of waterborne polyurethanes through composition control and structural optimization to meet the highly diversified modern demands is still one of the primary challenges faced by the polyurethane industry. Herein, various natural phenolic acids as neutralizers, for the first time, were applied for the preparation of castor oil-based cationic waterborne polyurethanes (CWPUs). The effects of these neutralizers on the microstructure (phase separation and hydrogen bond) and performance (mechanical properties, antibacterial activities, etc.) of the CWPUs were systematically investigated and compared with those of other commonly used neutralizers. The results indicate that apart from serving as neutralizers, phenolic acids also acted as antiplasticizing agents for the CWPU films by increasing the rigidity of the hard segment and hydrogen bond number. Also, the hydrophobic, rigid, conjugated structure of phenolic acids endowed the resulting CWPU films with excellent water resistance and UV protection. The introduction of phenolic acids also endowed the resulting polyurethane films with good antibacterial performance against both Gram-positive and Gram-negative bacteria. This study provides a novel and facile approach to tailor the performance of environmentally friendly cationic waterborne polyurethanes through natural phenolic acid neutralizers, along with eliminating long-standing issues of WPUs, such as irritating odor and air pollution.

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In this paper, two novel fully renewable internal emulsifiers have been successfully synthesized from epoxidized soybean oil and natural acids (adipic and pimelic acid) by a solvent-free and self-catalytic method. It is found that the emulsifiers show similar chemical structure and functions with typical petroleum based internal emulsifiers (dimethylol butanoic acid and dimethylol propionic acid), in which the hydroxyl groups act as a cross-linking and the carboxylic acid groups provide the ionic segment. These two novel internal emulsifiers were employed together with castor oil to prepare a series of high biocontent anionic waterborne polyurethane dispersions (PUDs). The unique structure of these two emulsifiers and their good compatibility with castor oil offer PUDs excellent storage stability. Additionally, the biocontent of the polyurethane are high up to 77.7%. Moreover, the adhesive properties of the biobased pressure sensitive adhesives (PSA) were comprehensively investigated by shear resistance, tack, and 180°peel strength test. The PSAs had a shear strength of 1.18 h to more than 100 h, a tack of 1.78−5.66 N, and a peel strength of 1.23−2.77 N/mm, all WPU PSA show good pressure sensitive adhesive properties, which would further expand the application of these novel vegetable oil-based waterborne PUDs.

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