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In this study, a series of bio-based polyols were prepared from olive, castor, corn, canola, rice bran, grape seed and linseed oil by thiol-ene photo-click reaction. The relationship between carbon-carbon double bonds in the backbone of vegetable oil fatty acid chains and the functionalities of the polyols was elucidated. The advantage and disadvantage between thiol-ene photo-click reaction and traditional methods for vegetable oil based polyols are summarized and compared. These bio-based polyols were used to prepare cationic waterborne polyurethane dispersions. With the increase of the vegetable oil based polyols’ hydroxyl values, the tensile strength, Young’s modulus, Tg, water contact angle of the waterborne polyurethane films increase from 1 to 11 MPa, 10 to 395 MPa, 23 to 50 °C and 38˚ to 46˚, respectively, but the elongation at break and thermal stability of them decrease. Thiol-ene photo-click reaction offers a bio-based platform to create a variety of waterborne polyurethanes that promises economic and environmental benefits.

In this study, dimethylol propionic acid (DMPA) and dimethylol butanoic acid (DMBA) were employed to synthesize the castor oil-based waterborne polyurethane dispersions (PUDs). The effects of these two emulsifier and their contents on the properties of the PUDs as well as their films were investigated systematically. The results show that as the emulsifiers contents increase, the particle size and zeta potential of the PUDs decrease while the tensile strength of the resulting PU films increase but thermal stability, water and chemical resistance decrease. The PUDs from DMBA exhibit smaller particle size than those from DMPA and the films from the former show higher tensile strength, higher elongation at break but lower thermal stability, lower water resistance. This work provides a new way to synthesize environmental friendly bio-based waterborne polyurethanes whose properties can be tuned according to their application, such as coating, ink, leather, styling products and so on.

In this study, castor oil and its derivative were used to prepare cationic waterborne polyurethane dispersion using N-methyl diethanolamine (MDEA) as ion center. The effect of polyol functionalities and the ionic chain extender contents on the particle size and antibacterial properties of the polyurethane dispersions, and thermo-mechanical, thermal stability, mechanical properties, water/solvent uptakes of the resulting polyurethane films were thoroughly investigated. Moreover, all the polyurethane dispersions exhibit enhanced antibacterial activity against Vibrio parahaemolyticus with the rise of MDEA content and the reduction of polyol functionalities, but rarely antibacterial activity to Listeria monocytogenes. To the best of my knowledge, this work for the first time extensively investigate the structure-property relationships of castor oil based cationic waterborne polyurethane dispersions and their polyurethane films.

In this work, a series of castor oil-based waterborne polyurethane composites were prepared with different amounts of sodium lignosulfonate as functional filler. The effect of the sodium lignosulfonate contents on the particle size and storage stability of the polyurethane composite dispersions was studied and discussed. In addition, the thermo-mechanical, thermal stability, mechanical properties and UV absorption of the resulting polyurethane films were characterized. The composite dispersion exhibits excellent storage stability and the bio-content of the resulting composite films is high up to 70%. In addition, it was found that the tensile strength and storage modulus increased with increasing the sodium lignosulfonate contents due to enhancement effect from the rigid benzene ring structure of sodium lignosulfonate and good compatibility between polyurethane matrix and the filler. The introduction of sodium lignosulfonate into WPU matrix rendered the excellent UV absorption of the composites due to the conjugated structures of lignin macromolecular. This work provides a new simple method to prepare environmental friendly bio-based waterborne polyurethane composites, which could find widely application in the field of UV absorption coatings and sunscreen cream.