Scientific Basis for Paint Stripping: Elucidated Combinatorial Mechanism of Methylene Chloride and Phenol Based Paint Removers
Memorandum rept. 7 Jun 2012-6 Jun 2013
NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
Pagination or Media Count:
Chemical paint strippers that include methylene chloride and phenol have been extensively used to remove polymeric coatings from a variety of substrates. Previous work helped to determine some aspects of the mechanism for methylene chloride-based paint strippers, but many questions remained. Clear films, partial formulation films, with pigments and no fillers, and full formulation films of current military polyurethane coatings were analyzed in this study. The coatings were characterized using DSC, TGA, Raman spectroscopy, X-ray photoelectron spectroscopy, attenuated total reflectance FTIR, confocal laser microscopy, and NEXFAS spectroscopy. Results showed that the different components of the paint stripper had synergistic mechanistic effect. The methylene chloride acts by penetrating the coating and enabling other solvents to subsequently penetrate the coating. The main component responsible for coating degradation is phenol. Water acting as a protic polar solvent activates the phenol and increases observed degradation. The hydroxypropyl methylcellulose added to paint strippers to emulsify the solution deposited a thin film on the surface of the coatings, increasing the retention time of the solvents.
- Inorganic Chemistry
- Organic Chemistry
- Solvents, Cleaners and Abrasives