(337f) Lipophilic Super-Absorbent Polymer Gels As Surface Cleaners for Oil and Grease

Increasingly stringent environmental regulations on volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) demand the development of disruptive technologies for cleaning weapons systems and platforms.  Currently employed techniques such as vapor degreasing, solvent, aqueous, or blast cleaning processes suffer from shortcomings in environmental friendliness, personnel health and safety, cleaning efficiency, cost-effectiveness, management of contaminated cleaning media, or in maintaining the integrity of equipment material surfaces.  Lipophilic super-absorbent swelling gels have been developed that will not only absorb the oil and grease from these machine parts, but will also act as an automated sweeper due to the self-generating mechanical force of the gel. An octadecylacrylate-co-ethylene glycol dimethacrylate (ODA-co-EGDMA) lipophilic gel (G-1) and commercially available Alkylstyrene Copolymer (imbiber beads) were evaluated for swelling and oil sorption capacity. Along with the imbiber beads and G-1 gel, poly stearylacrylate-co-ethyleneglycol dimethacrylate neutral gel (NG-18), another lipophilic super-absorbent gel, was synthesized and tested. For each gel, the swelling degree and the oil absorption capacity were quantitatively investigated at 0-60⁰C using a variety of polar and nonpolar solvents. The mechanical strength of each gel was studied by measuring compression strength, and  cross-linking of the polymers was studied using infrared spectroscopy. The cleaning tests were performed using metal coupons. Details of gel preparation and  evaluation of oil sorption capacity will be presented.