NCO Analysis
Necessary to determine isocyanate content in prepolymer
Procedure for NCO analysis
- Weigh 3.5-6.5g of prepolymer into dried flask
- Add 20 mL of dibutyl amine solution
- Add 50 mL of dry tetrahydrofuran
- Stir until homogeneous
- Add 100 mL of anhydrous isopropanol