WAX-BASED EMULSIFIERS FOR USE IN EMULSIONS TO IMPART WATER REPELLENCY TO GYPSUM WALLBOARDS

Abstract

<p>Maleation is a common means of modification for many commodity polymers and is used to several ends. In this study, various waxes were functionalized with maleic anhydride through several maleation processes, with the end goal of obtaining a cost effective processes to make emulsifiers to be used in emulsions that impart water-resistance to building products, such as gypsum wallboards. Research was done in collaboration with an industrial partner, in order to replace commercially available emulsifiers currently being used in their processes with a less costly product that could easily be made on-site based on their consumption requirements, through a solvent-free approach. Reactions involving both the free-radical initiated maleation of paraffin waxes and thermal addition of maleic anhydride to alpha-olefins were examined extensively. It was found that emulsions with properties matching or exceeding those of control emulsion formulations were obtainable using experimental emulsifiers made through both maleation methods. When used in gypsum wallboards, emulsifiers made through thermal maleation showed levels of water-repellency that matched or exceeded those of control formulations at lower loading levels, while emulsifiers made through free-radical maleation were subject to performance issues.</p>