CO<sub>2</sub>‐Redispersible Polymer Latexes with Low Glass Transition Temperatures

In this work, acrylic latexes are prepared through surfactant‐free emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA). CO2‐responsive 2‐(diethyl)aminoethyl methacrylate (DEAEMA) is used as a co‐monomer. The resulting latexes can be easily coagulated by adding a small amount of caustic soda. Once washed, coagulated particles could be redispersed into water to prepare stable latexes with CO2 and ultrasonication. CO2‐redispersibility of the latexes is examined as a function of glass transition temperature of the polymers having different MMA/BA ratios. It is found that, while high MMA content latexes are easily CO2‐redispersed, it is challenging to re‐disperse high BA content latexes. For latex particles with T g below ambient conditions, coagulation with caustic soda leads to the fusion of individual particles, and the particles are no longer redispersible. This work provides a mechanistic insight and practical guidance for the applicability of CO2‐responsive amine‐containing molecules (employed as comonomer, initiator, surfactant, and so on) in developing CO2‐redispersible latex products. image

CO₂‐Redispersible Polymer Latexes with Low Glass Transition Temperatures Journal Articles