Water-borne polyurethane modified by stearyl acrylate for water repellents
Double bond end-capped water-borne polyurethane (DWPU) was synthesised from toluene diisocyanate, hydroxypropyl polysiloxane, trimethylolpropane, N-methyldiethanolamine, and hydroxyethyl acrylate. Then water repellents with long-chain hydrophobic alkyl structure were obtained by radical copolymerisation of stearyl acrylate (SA) and DWPU. The waterproofing performance and other properties of the water repellents were studied for different SA contents.
Reduction of water absorption
The results showed that, for the water repellent with SA content of 50 wt%, the water absorption of the film reduced to 4.29% while the water contact angle of fabric coated by the water repellent rose to 141.5°. In addition, the optimum SA content of the water repellent was 40%, achieving the highest score of 85 points in the waterproof performance evaluation.
The study is published in: Journal of Coatings Technology and Research November 2018, Volume 15, Issue 6, pp 1283–1292.