ARS | Publication request: Lipophilic super-absorbent swelling gels as cleaners for use on weapons systems and platforms

Submitted to: Government Publication/Report
Publication Type: Other
Publication Acceptance Date: February 1, 2012
Publication Date: February 1, 2012
Citation: Boddu, V. M., Uchimiya, S. M., Ohta, M., Sada, K., Myers, C., Ziegler, W., and Torres, T. 2012. Lipophilic Super-Absorbent Swelling Gels as Cleaners for Use on Weapons Systems and Platforms. DoD SERDP Weapons Systems and Platforms WP-1761 final report. Champaign, IL: U.S. Army Engineer Research and Development Center. 75 p.

Technical Abstract: 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. We propose to use novel lipophilic super-absorbent swelling gels as a disruptive solid state cleaning technology that will facilitate the Department of Defense (DoD) in overcoming limitations of currently employed cleaning techniques. 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 polyelectrolyte gel (EG-18) and poly(stearylacrylate-co-ethyleneglycol dimethacrylate) (SA-co-EGDMA) lipophilic neutral gel (NG-18) were evaluated for swelling and oil sorption capacity. The results were compared with a commercially available alkylstyrene copolymer (imbiber beads). For each gel, the swelling degree and oil absorption capacity were quantitatively investigated at 0-60°C using a variety of polar and nonpolar solvents. The cross-linking of the polymers was studied using infrared spectroscopy, and the compression strength was determined. The cleaning tests were performed on metal coupons using the ASTM methods and on field samples obtained from Naval cleaning facility. NG-18 and EG-18 gels removed particulate contaminants and absorbed oils and grease on metal and non-metal surfaces without causing abrasion. The gels are also recyclable. The cleaning ability of gels was compared with with the standard solvent cleaner trichloroethylene (TCE), following ASTM test methods and MIL-PRF-680B procedure with MIL-PRF-10924 test grease. Polymer gel cleaners exhibited analogues extent and rate of cleaning as the TCE cleaning process. In conclusion, the recyclable superabsorbent polymer cleaners developed in this research will allow drastic reduction in the use of VOC containing solvents and HAP release.