Polymer dispersions represent a very large and growing coating materials segment. Vinyl addition emulsion polymers represent the single largest polymer dispersion category employed as binders in coating applications, because they enable water-based environmentally friendly solvent-free or low solvent coating formulations. Emulsion polymer technology has evolved rapidly in the past decades to meet increasingly stringent volatile organic compound (VOC) regulations and allow environmentally friendly water-based binders to successfully compete in demanding industrial, aftermarket, maintenance and packaging applications. Key technical advances include morphological control to enhance rheological and film-forming properties, new crosslinking chemistries to enhance physical properties, functional monomers to enhance adhesive and surface properties, and hybrid chemistries to providing corrosion resistance, toughness and a host of other benefits. In addition, emulsion polymers have been successfully exploited in many new applications from medical diagnostics to optical applications. New chemistry and process technology developments are further enhancing emulsion polymer utility in a wide range of applications from UV curable coatings to optical applications.