Propynol ethoxylate CAS:3973-18-0 PME (Propynol ethoxylate) (C5H8O2) Appearance: Clear colorless to yellowish liquid Assay: â?¥98% Density g/cm3 (20): 1.01~1.04 PH: 6.0~7.0 Refractive Index(20): 1.4465~1.4500 Application: Leveling agent, brightener for nickel plating