PNVCL precipitation polymerization can be used in both n-hexane and cyclohexane. However, the synthesis of n-vinylcaprolactam and vinyl imidazole copolymer cannot use n-hexane or cyclohexane because n-vinylcaprolactam (1-NVI) is insoluble. N-hexane or cyclohexane, it is difficult to achieve precipitation polymerization with a single solvent.
1-NVI is only soluble in toluene. The n-vinylcaprolactam plant is considered to achieve precipitation polymerization using a mixed solvent of n-hexane and toluene. The observed reaction phenomena were also basically the same, and both of them showed turbidity at one end of the reaction. As time increased, more and more precipitates were obtained, and finally a white powder was obtained, and the yield was over 95%.