The Role of Carboxylic Acid on the Characterization and Evaluation Seed Emulsion of Styrene/ Butyl Acrylate Copolymers Lattices as Paint

Series of emulsion lattices having different composition ratios of styrene/butyl acrylate (St/BuA) as base monomers in conjunction with acrylic acid (AA) and/or methacrylic (MAA) were prepared and characterized. The preparation was carried out in industrial scale in semi batch reactor at pH range of 3-5 using potassium persulphate (KPS) as an initiator, sodium luaryl sulphate (SLS) as an emulsifier and nonyl phenol ethoxylated (NP9) as co-emulsifier at 80C for 4 hours. The prepared lattices were characterized using XRD, TGA, DSC, TEM and rheological properties. The obtained lattices was examined and evaluated as binder in standard paint formulation using pencil hardness test, adhesion to metal and washability. The data showed that all the prepared emulsion lattices had non-Newtonian pseudoplastic character. Moreover, the dynamic oscillation for all examined lattices samples clarified that the elastic modules (storage modules) governed by the variation of the monomer composition ratios. The polymer having (AA) monomer in its composition was of lower thermal stability than that having the same composition content of (MAA). [Nature and Science 2010;8(8):94-103]. (ISSN: 1545-0740).