Abstract:

Three kinds of N-vinyl pyrrolidone （NVP）/N-vinyl imidazole （NVI） polymers （VP/VI polymers） with different monomer ratios were synthesized, and all samples were characterized and analyzed by Ubbelohde viscometer, Fourier transform infrared spectroscopy （FT-IR） and gel permeation chromatography （GPC）. The results showed that the K values of the three copolymers were around 30, and the weight average molecular weights （M_W） of the three copolymers were 37 848, 22 656 and 8 111, respectively. The anti-staining properties of the VP/VI polymers were tested by ultraviolet-visible spectrophotometer （UV-vis） and anti-staining experiments. With the addition of VPVI-P, VPVI-5 and VPVI-7,the maximum absorption wavelength （λ_max） of the Direct Red 28solution was red shifted from 499 nm to 520 nm, 527 nm and 531 nm, respectively. The absorbance value at λ_max was increased from 0.30 to 0.39 as the mass concentration of the VP/VI polymer was increased from 0 g/L to 5.0×10^-2 g/L. The λ_max of the Direct Dark Blue solution was red shifted from 558 nm to approximately 576 nm and the absorbance at λ_max was increased from 0.15 to around 0.35 as the mass concentration of the VP/VI polymer was increased. It indicated obvious interactions between the VP/VI polymers and the dye molecules （Congo red and direct blue）. It showed better performance in the anti-staining experiments as the content of NVI component was increased in the polymers.

Key words: N-vinyl pyrrolidone, N-vinyl imidazole, VP/VI polymer, polyvinylpyrrolidone, anti-staining