Preparation and Properties of Organosilicon-Modified High Solid Content Hydroxy Polyacrylate Aqueous Dispersions

Two-component waterborne polyurethane is composed of water-based polymer polyols and water-dispersible polyisocyanates. Among them, hydroxyl polyacrylate aqueous dispersion (PAD) has attracted extensive research interest owing to its small particle size and exceptional film-forming performance. However, conventional PAD suffers from critical limitations, including low solid content and insufficient chemical resistance of cured film, which severely restrict its industrial applications. To address these drawbacks, a sulfonic acid-containing vinyl hydrophilic monomer was synthesized to fabricate high-solid and low-viscosity PAD, followed by organosilicon modification. The effects of organosilicon type and dosage on the properties of PAD and its cured film were systematically investigated. Results reveal that the dosage of vinyl-based sulfonate enhances the solid content of PAD and improves coating transparency. Organosilicon incorporation effectively boosts the chemical resistance of the coating film but compromises the storage stability of PAD. Notably, PAD modified with vinyl triisopropoxysilane (KH1706) exhibits optimal overall performance, with a solid content of 45%, a low viscosity of 357 mPa s, along with excellent chemical resistance and thermal stability.