Preparation of UV-curable emulsions using PEG-modified urethane acrylates: The effect of nonionic and anionic groups

Abstract

SYNOPSISTo prepare self-emulsificable urethane acrylate resin, PEG-modified urethane acrylates (PMUA), containing polyoxyethylene chains as a terminal hydrophilic group and urethane acrylate anionomers (UAA) incorporated dimethylolpropionic acid (DMPA) as a pendant hydrophilic one were synthesized. For PMUA emulsions, the reaction molar ratio of PEG to 2-hydroxyethyl methacrylate (2-HEMA) significantly influenced the viscosity and droplet size of the emulsion and tensile strength of cured films. These emulsions were stable to pH change and the addition of electrolyte, but coagulated around 60°C. In the case of UAA, emulsions, however, were very stable to elevated temperatures and coagulated in adding even a little bit of electrolyte. For soap-free emulsions of the mixture of PMUA and UAA, emulsion stabilities of these mixtures against temperature, pH change, the addition of electrolyte, and the rate of shear and freeze-thaw increased synergetically. Additionally, the tensile strength of cured films was also improved.

Synthesis of Water-Soluble Urethane Acrylate Cationomers and Their Ultraviolet Coating Properties

“…This seemed to be attributed to the lower concentration of the vinyl groups. However, for the urethane acrylate cationomer films, it is notable that the maximum stress was much higher than those in the literature [2,10,11] (generally, the maximum stress of the conventional urethane acrylate films prepared ORDER REPRINTS without using a reactive diluent was in the order of 2~10MPa). Under such results, it was reasonable to expect that the 5 minute-curing was suitable for preparation of the acrylate cationomer films.…”

“…In the former case, usually, it is common practice to add surfactants to stabilize the emulsion or dispersion once it is formed [4][5][6]. In the latter case, water-soluble or dispersible resins have been achieved by the incorporation of hydrophilic sites such as nonionic and ionic groups into the molecular backbone or end without adding surfactants [7][8][9][10][11]. Alternatively, however, some deterioration in performance has been observed due to the presence of these surfactants which remain in the cured film and which impart sensitivity to the finished coating.…”

Synthesis of nanophase‐separated poly(urethane‐co‐acrylic acid) network films and their application for magnetic nanoparticle synthesis

“…Although amphiphilic urethane acrylate chains having hydrophilic moieties, such as carboxylic, sulfonic acid, amino groups, and polyoxyethylene (POE) groups, have been widely used as water‐borne UV coatings,19, 20 little work has been reported on the use of these chains as nanocomposite matrix. In our previous works, we could synthesize nanophase‐separated amphiphilic polyurethane networks through crosslinking polymerization of urethane acrylate nonionomers (UANs) as well as magnetic nanoparticles within these polyurethane networks 21, 22.…”

Synthesis of Magnetic Nanocomposite Based on Amphiphilic Polyurethane Network Films

“…These reactors are generally formed by microphase‐separation between hydrophilic and hydrophobic segments in amphiphilic polymer chains 4,7–9. Although amphiphilic urethane acrylate chains having hydrophilic moieties such as carboxylic, sulfonic acid, amino groups and polyoxyethylene (POE) groups have been widely used as water‐borne UV coatings,12,13 their application as nanocomposite matrix has not been reported. In our previous works, we could synthesize microphase‐separated amphiphilic polyurethane networks using amphiphilic urethane acrylate (AUA) ionomer and non‐ionomer having pendant carboxylic acid group and terminal hydrophilic poly(ethylene oxide) chains 14–18.…”