Synthesis and characterization of alkylated N-vinylformamide monomers and their polymers

N‐alkyl‐N‐vinylformamide monomers (alkyl: n‐butyl, hexyl, decyl, and dodecyl) are synthesized in two steps: first, preparation of N‐vinylformamide potassium salt by the reaction of N‐vinylformamide (NVF) with potassium t‐butoxide, then reaction with alkyl bromide. All four monomers are liquid and are characterized by IR, 1H NMR, 13C NMR, and mass spectra. They exist as rotomers in solution and a 2D NOE experiment on the N‐hexyl containing polymer shows the E isomer to be favored. The polymerizability of the four monomers is from good to fair, depending upon the length of alkyl chain on the N‐atom‐‐the longer the chain length, the lower lower the polymerizability of monomer. The hydrolysis of poly(N‐hexyl‐N‐vinylformamide) and poly(N‐dodecyl‐N‐vinylformamide) under acidic and basic conditions was examined. Studies show that hydrolytic cleavage of formyl groups of poly (N‐alkylated‐N‐vinylformamide) depends on the hydrophobicity of the alkyl substituent on the N‐atom under acidic conditions; both polymers were hydrolyzed to only a minor extent under alkaline conditions. The N‐alkylated monomers can copolymerize with NVF and demonstrate amphiphilic properties. The copolymers demonstrate a critical aggregation concentration above which they can solubilize a water insoluble dye; the N‐hexyl containing copolymer stabilizes a castor oil‐in‐water emulsion. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4994–5004, 2004 Procedures have been developed to N‐alkylate N‐vinylformamide. The N‐alkylated derivatives can be polymerized and copolymerize with N‐vinylformamide. The copolymers are amphiphilic, those containing N‐butyl, N‐hexyl, and N‐decyl groups demonstrate a critical micelle concentration above which they can solubilize an azo dye of low water solubility. The N‐hexyl containing copolymer is shown to stabilize a castor oil in water emulsion. The higher N‐alkylated polymers are surprisingly resistant to base hydrolysis. The N‐alkylated amides exist in two rotamers about the carbonyl‐nitrogen bond, the E isomer favored.