High-solid, low-viscosity waterborne polyurethane: based on multiparticle size composite emulsification
Researchers found that the combination of an emulsion with large particles (WPU-L) with a variety of emulsions with small particles (WPU-S) enables a high solids content, good emulsion stability and excellent coating properties in the resulting WPU-L/WPU-S = 5/1 emulsion.
In a current research, waterborne polyurethane (WPU-SL) with high solid content and low viscosity was successfully prepared by compounding large particle size emulsion (WPU-L) with a variety of small particle size emulsions (WPU-S) by investigating the effects of small particle size type, particle size ratio, and volume ratio on the emulsion properties. A series of characterization techniques of the waterborne polyurethane was carried out by FTIR, DSC, contact angle, viscometer, particle size meter, and universal testing machine.
The results show that the WPU-L/WPU-S = 5/1 emulsion has a high solid content, good emulsion stability, and excellent coating film properties. When WPU-S1 and WPU-S3, two small particle size emulsions with a particle size ratio of 2.45 and 3.79, were emulsified with WPU-L, the solid content was up to 61.23%, the viscosity was only 342 mPa s, the tensile strength reached 20.97 MPa, and the adhesion grade was 5B, which was the most excellent overall performance, showing satisfactory results.
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Innovative routes to producing water-borne acrylic polyols for 2K PU topcoats, new silicone additives for high-performance anti-graffiti polyurethane applications, environmentally compliant two-component water-borne urethane dispersions and making ecological PU coatings a reality: using renewable acetone from bio-based, bio-circular and circular feedstocks.
If you are interested in more information about the research findings on the combination of an emulsion with large particles (WPU-L) with a variety of emulsions with small particles (WPU-S), enabling high solids content, good emulsion stability, and excellent coating properties in the resulting WPU-L/WPU-S = 5/1 emulsion, the reserach has been published in Journal of Coatings Technology and Research in December 2023.
