{
    "protocol": "UV curable urethane acrylate oligomer containing ammonium salts for anti-fog coating was developed.Monomers, including ethanolamine and 2-butanone, are purified by vacuum distillation before use. SY-40M is used without purification. Dimethyl sulfate is purified by vacuum distillation prior to use. Isophorone diisocyanate (IPDI) and dibutyltin dilaurate (DBTDL) are sourced from reputable suppliers. TLC analysis is performed using TLC Silica gel $60\\mathsf{F}_{254}$ for monitoring the reactions.Ethanolamine (10.16 g, 0.166 mol) was added to a 250 mL three-neck flask equipped with water bath, thermometer, refluxing condenser, dropping funnel, and magnetic stirring bar, and heated to 60°C with stirring. 86.55 g of alkyl glycidyl ether (Sy 40M) was slowly added and the mixture was maintained for 2 h at 70°C. Dimethyl sulfate (20.99 g, 0.166 mol) and methyl ethyl ketone (MEK, 29.8 g) were added dropwise to the stirred mixture over 3 h, while maintaining the temperature at 60°C. The salt group of the final product was identified by titration of the remaining amine group with 0.1 N HCl solution, indicating that 80% of the total amine group was converted into quaternary ammonium group. The reaction product was identified with 1H NMR (CDCl3, 300 MHz): 4.17 ppm (N+-CH2C(H)(-OH)-CH2), 4.01 ppm (N+-CH2C(H)2OH), 3.52 ppm (CH2CH(-OH)-C(H2)O), 3.43 ppm (N+-CH2C(H)2OH), 3.39 ppm (N+-CH2C(H)(OH)CH2), 3.29 ppm (N+-CH3), 1.22 ppm O(CH2)C(H)3.To a solution of IPDI (34.5g, 0.16mol) and PETA (100g) in MEK (100mL), DBTDL (0.25g) was added dropwise at 10°C with stirring. After complete addition, the mixture was stirred at 10°C for 4h. The reaction progress was analyzed by TLC using ethyl acetate: hexane = 1:2 (v/v). The AS monomer (96.2g) in MEK (20mL) was added to the above reaction product over 4h, while maintaining the temperature at 20°C. The reaction product was identified with 1H NMR (CDCl3, 300MHz) and FT-IR.UV curable anti-fog (AF) compositions were prepared by mixing homogenously UV-UAO with reactive diluents (PETA:DPHA = 8.5:1.5 by weight) and the photoinitiator (1- Hydrophenyl ketone, Irgacure 184 from Ciba Specialty Chemicals, maximum peak of absorption: 245-330 nm). Different amounts of UV-UAO (55-70 wt.%) were added into the above composition and the photoinitiator concentration was kept constant at 5 wt.% all on the basis of final formulation. A 20-μm thick coating of the resin composition was applied on the polycarbonate (PC) using bar applicator and then cured with 80 W/cm light a medium pressure mercury lamp of conventional UV equipment."
}