Propargyl alcohol propoxylate CAS:3973-17-9 PAP (Propargyl alcohol propoxylate) (C6H10O2) Appearance: Clear colorless to yellowish liquid Assay: â?¥98% Density g/cm3 (20): 0.97~0.98 PH: 6.0~7.5 Refractive Index(20): 1.4430~1.4455 Application: Leveling agent, brightener for nickel plating