N-methylpyrrolidone General Information NMP has been commercially produced in the United States since the mid-1960s. The typical pH of NMP is 8.0 to 9.5. It is a highly polar, colorless liquid with a mild amine odor. Some applications of NMP are large-scale recovery of hydrocarbons and aromatics by extractive distillation and the preparation of semipermeable membranes used for ultrafiltration and reverse osmosis separation processes. In the agricultural industry, NMP has been used in the formulation of insecticides, pesticides, fungicides, herbicides, seed treatment products, and bioregulators. NMP is exempt from the requirement of a tolerance when used as a solvent or cosolvent in pesticide formulations. In the plastics industry, NMP is used as a solvent for natural and synthetic plastics, waxes, resins, and various types of paints. It is also used in spinning fibers and yarns and to synthesize new polymers. In the electronics industry, NMP has been used for removing positive photoresists from silicon wafers for integrated circuits. NMP is also an active ingredient in commercially available water-miscible, semiaqueous cleaners used to deflux printed wiring boards (PWBs) after wave solder or vapor phase reflow. These solvent blends dissolve various contaminants ranging from flux and pyrolized flux to inorganic contaminants and fingerprints. They are designed to clean through immersion at ambient temperatures but cleaning can be enhanced through either ultrasonics, spraying, spraying under immersion, or agitation. NMP is effective for softening or removing many types of adhesives. For example, NMP is used to debond disk drive read/write heads during the manufacturing process. NMP dissolves polyamides, polyimides, polyesters, polystyrenes, polyacrylonitriles, polyvinyl chlorides, polyvinyl acetates, polyurethanes, polycarbonates, polysulfones, polymethylmethacrylate, and many copolymers. Assemblies containing these materials should be tested before using NMP. NMP will dissolve or swell Buna-N rubber, natural rubber, and neoprene. State Information | Glossary | Conversion Checklist | Comments Home | Process Advisor | Alternatives | Links | Search All SAGE material, Copyright© 1992, Research Triangle Institute Last Update: 07 May 2001 sage@rti.org http://clean.rti.org/alt.cfm?id=nmp&cat=gi