Pme (propynol ethoxylate) Pme (propynol ethoxylate) Pme, propynol ethoxylate, cas no. 3973-18-0, c5h8o2 Appearance: clear colorless to yellowish liquid Assay: 98% Density g/cm3 (20µ): 1.01~1.04 Ph: 6.0~7.0 Refractive index(20µ): 1.4465~1.4500 Application: leveling agent, brightener for nickel plating