Isolation of the interaction between CaCO3 filler and acrylic binder. Part I: Effect of the surfactant and functional monomer type

•Waterborne paint-like blends prepared with acrylic binders and CaCO3.•Avoid the use of sodium acrylate dispersing agent.•Effect of amount and type functional monomer on the interaction with CaCO3.•Polymerizable surfactant and MAA functional monomer presented best performances.•Higher amounts of functional monomer led to water soluble oligomers, detrimental for the interaction with CaCO3. The aim of this work is to isolate the interaction between waterborne acrylic polymer and calcium carbonate (CaCO3) fillers, in order to build a deeper understanding of the factors influencing the dispersion and adhesion of CaCO3 fillers to acrylic binders. Therefore, along this work waterborne paint-like blends with applicable rheology have been prepared without the use of any additive, in order to completely isolate the interaction between the acrylic polymer and filler particles. In this paper we report the preparation of CaCO3/Poly(methyl methacrylate-co-butyl acrylate) P(MMA/BA) latex blends without the use of any additive. This has been possible thanks to the direct addition of CaCO3 powder to diluted latex. Paint-like blends have been prepared with latexes synthesized with different surfactants at the PVC value of 40. More precisely, one conventional surfactant (Dowfax 2A1) and two polymerizable surfactants: Sipomer PAM-200 and Latemul PD-104 have been used. Latexes with the three different types of surfactants have been synthesized with acrylic acid (AA) functional monomer as well as with methacrylic acid (MAA) and without the use of any functional monomer. The effect of all these variables (surfactant type and functional monomers) has been investigated by analysing the final paint-like film properties (AFM, gloss and scrub resistance). Moreover, the interaction between the different latexes and pure surfactants with CaCO3 filler has also been studied by NMR measurements. This has been carried out by investigating the adsorption capacity of polymer particles and surfactants on the surface of CaCO3 particles. Higher gloss value, better CaCO3 dispersion, higher scrub resistance and higher adsorption capacity of polymer particles on CaCO3 have been observed for films prepared with the latex containing Latemul PD-104 surfactant and MAA functional monomer.