Hybrid WPUA dispersion synthesized with Bis-GMA grafting agent

Scientists synthesized new hybrid waterborne polyurethane dispersions by using bisphenol A-glicidylmethacrylate (Bis-GMA).

The scientists wanted to create chemical bonds between polyurethane and polyacrylate chains by grafting with Bis-GMA.Source: kasto – stock.adobe.com. -

The study shows that mean particles size is reduced when Bis-GMA is used instead of HEMA. New hybrid waterborne polyurethane/acrylate (WPUA) dispersions were synthesized by grafting with bisphenol-A-glycidyl dimethacrylate (Bis-GMA) in order to create chemical bonds between polyurethane and polyacrylate chains. WPUAs were prepared by using prepolymer self-emulsifying method with isophorone diisocianate, poly(tetramethylene ether) glycol, dimethylolpropionic acid, and ethylenediamine in the polyurethanic part, and styrene and n-butyl acrylate in the polyacrylate portion. A redox pair system consisting of ascorbic acid and hydrogen peroxide were used as polymerization initiator.

Increasing the cross-cut adhesion to stainless steel

The particle size of the WPUA dispersions increased by increasing the Bis-GMA/1,4 butanediol ratio, stable dispersions of negatively charged particles were obtained, and they had low viscosity (around 1.3 mPa.s) in spite of the relatively high solids content (27 wt%). Higher thermal stability was obtained when 50 mol% of chain extension was carried out with Bis-GMA. Using Bis-GMA/BD, instead of HEMA, as grafting agent, allowed obtaining hybrid polyurethane dispersions with the lowest mean particle size and better colloidal stability. Finally, the addition of 35 wt% Bis-GMA increased noticeably the cross-cut adhesion of polyurethane/acrylate coatings to stainless steel.

Read the complete article in Progress in Organic Coatings Volume 118, May 2018, Pages 30-39.

Book tip:

The book Polyurethanes for Coatings begins is useful for familiarize newcomers with the key concepts of polyurethane chemistry. Specialists can update their knowledge about current developments and perspectives.

Hersteller zu diesem Thema

This could also be interesting for you!