The present application provides an aqueous emulsion polymer free of ethyl acrylate comprising (a) monomers (i) methyl acrylate, (ii) butyl acrylate and (iii) methacrylic acid; (b) crosslinker and (c) at least one surfactant. The present invention also provides the use of such emulsion polymers along with acid, cationic polymer, oil and other additives as low pH rheology modifiers and suspending aids for surfactant based micelle technology, emulsions and complex fluids in personal care, home care and industrial applications.