Improving the property of castor oil-based waterborne polyurethane
During the study, sapium sebiferum oil-based polyols (SOP) were prepared. Then, modified castor oil based waterborne polyurethane was prepared by using SOP, castor oil and isocyanate as raw materials. The particle size and the chemical structure of the emulsions were characterised. Anti-graffiti properties, water contact angle, mechanical properties and thermal properties of the films were tested.
Good anti-graffiti performance
When the mass ratio of the SOP to castor oil increased, the water contact angle of the modified film increased by nearly 20°, and it showed good anti-graffiti performance, which can be erased by dry bumf without leaving trace after being written by marker. In addition, the tensile strength and elongation at break can be improved 2.2 and 2.8 times than before, respectively, which may be related to the addition of crosslinking in the polyurethane by polyhydroxy SOP.
The study has been published in Progress in Organic Coatings, Volume 168, July 2022.