The effect of natural carbon content components on dispersion properties

 
Sustainable paints and coatings is one of the main development directions in recent years. Most solutions focus on increasing the biogenic carbon content in polymeric materials that act as binders. Main source of carbon for polymer dispersions are monomers used to synthesis of copolymers with specific properties. For this reason replacing fossil based monomers with monomers from renewable resources is the most effective way to achieve high percentage of bio-carbon in the product. Polymers containing carbon from renewable resources should although be a competitive solution comparing with their fossil based substitutes especially from the final performance perspective. For aqueous polymeric dispersions used as binders in solvent-free paint formulations main requirements are focused on excellent film forming at room temperature as well as high pigment-binding capacity, which is defined by wet scrub resistance measurement. Petrochemical dispersions can easily reach the first class wet scrub resistance with thickness loss less than 5 µm (scrubbing cycles according to ISO 11998 standard). Could bio-dispersions reach this level of resistance without any improvements in the paint formulation? What is the maximum bio-carbon content that could be obtained without huge reduction of application parameters? This work is an attempt to study the effect of petrochemical derivative monomers replacement with partially plant based monomers in semi-batch emulsion polymerization process. Standard monomers like methyl methacrylate, butyl acrylate or 2-ethylhexyl acrylate were gradually replaced with vegetable oils derived fatty acids acrylic esters to achieve more than 30% of C14 carbon isotope content. Latex film properties were studied through differential scanning calorimeter (DSC) to determine glass transition temperature of copolymer and minimum film forming temperature (MFFT) was controlled to avoid adding a coalescent. Selective parameters comparison for adequate binders were examined in high quality paint.