N-vinyl acetamide purificn. to remove acet-amide by extn. - with aromatic hydrocarbon and conc. aq. salt soln. and use in polymer and poly-vinyl:amine prodn.

摘要

Purificn. of N-vinylacetamide (I) contaminated with acetamide (II) is carried out by (a) extracting impure (I) with an aromatic hydrocarbon solvent (III) to give a soln. of (I) and a smaller amt. of (II) in (III), (b) contacting this soln. with a conc. aq. salt soln. (IV), and (c) sepg. the phases to give a purer (I)/(III) soln. Pref. (III) is benzene, toluene, xylene or ethylbenzene. (IV) contains NaCl, KCl, MgCl2 or CaCl2 and pref. is satd. In particular, (III) is toluene and (IV) is brine. The impure (I) is obtd. by condensation of (II) and acetaldehyde to ethylidene-bis-acetamide (VI), followed by pyrolysis. USE/ADVANTAGE - The (I) obtd. is pure enough for polymerisation and is claimed for use in the prodn. of poly(N-vinylacetamide) (V) by polymerisation in the aq. soln., either as soln. or emulsion in oil, and (V) is claimed for use in the prodn. of poly(vinylamine) by hydrolysing the amido gps. to amino gps. or amine salts.