Hydroxyalkyl acrylamides prepared in purified state from an alkylol primary or secondary amine and an acid halide of acrylic acid or an a -substituted acrylic acid wherein the a -substituent is a halogen or a hydrocarbon-radical (see Group IV (b)), may be polymerized alone or in conjunction with other polymerizable acrylamides or a -substituted acrylamides. Water-soluble polymers are obtained by polymerizing in bulk in presence of a catalyst and interrupting the polymerization at a stage where the yield ranges from about 10 to 50 per cent polymer, or by polymerizing in the presence of a liquid which is a solvent for the monomeric material but not for the resulting polymer, such a solvent being, e.g. acetone or tertiary butanol, or by polymerizing in presence of an organic solvent which confines the molecular weight to a range where the polymer is water-soluble, e.g. an aliphatic alcohol, dimethyl formamide, or chloroform or other aliphatic halogen compound as described in Specification 648,252. The a -substituted acrylamides which are di-N-alkylol-substituted may only be polymerized per se by the method described in Specification 648,250. In examples (1) N-b -ethanol methacrylamide is polymerized at ordinary temperature by means of ultra-violet, the monomer being in a sealed tube or in acetone solution under vacuum; (2) N-methyl-N-ethanol acrylamide is polymerized alone by means of ultra-violet light or benzoyl peroxide; (3) N-ethanol methacrylamide and methacrylamide in methanol are polymerized together, yielding a water-insoluble interpolymer; (4) N-methyl-N-ethanol methacrylamide and N-ethanol methacrylamide are polymerized together in a sealed tube also yielding a water-insoluble polymer. In addition to the mono-N-ethanol methacrylamide, the di-N-ethanol methacrylamide and corresponding a -propyl, butyl, phenyl, cyclohexyl and chloro-substituted acrylamides, the N-propyl-, N-butyl, and N-amyl - N - b - ethanol methacrylamides and the N-ethanol-, di-N-ethanol- and N-methyl-N-ethanolacrylamides are other suitable monomers. The subject-matter of the above-mentioned Specifications is disclaimed. The Specification as open to inspection under Sect. 91 relates to the polymerization of the purified monomers derived from any acrylyl acid halide and the alkylolamine and describes the polymerization of N-b -ethanol methacrylamide and N-ethanol acrylamide, respectively, in methanol in sealed tubes, the products being water-soluble. This subject-matter does not appear in the Specification as accepted.ALSO:Hydroxyalkylacrylamides in highly pure state are prepared by reacting an acid halide of acylic acid or of an a -substituted acrylic acid, in which the a -substituent is halogen or a hydrocarbon radical, with more than one molecular proportion of an alkylol primary or secondary amine in the presence of an inert diluent which is a solvent for the resulting hydroxylalkylacrylamide but a non-solvent for the alkylolamine hydrogen halide formed during the reaction, and from which the alkylolamine hydrogen halide precipitates during the reaction in solid or crystalline form, and separating the hydroxyalkylacrylamide from the reaction mixture. Acetonitrile is an example of such a diluent. Preferably, at least two mols. of the alkylol amine are used per mol. of the acrylyl halide whereby all the hydrogen halide formed is neutralized, thus obviating the use of another neutralizing agent. The precipitated amine salt may be filtered off and the filtrate further purified by distillation under reduced pressure in presence of a polymerization inhibitor. The acrylyl halides and alkylol amines are preferably reacted at about 10 DEG C. or below. In examples: (1) methacrylyl chloride is reacted with ethanolamine in acetonitrile yielding N-b -ethanol methacrylamide, and (2) methacrylyl chloride is reacted with N-methyl ethanolamine in acetonitrile, yielding N - methyl - N - b - ethanol methacrylamide; (3) acrylyl chloride is reacted with ethanolamine in acetonitrile to yield N-b -ethanolacrylamide. There may be prepared as well as the N-b -ethanol methacryl amide, the N-diethanol acrylamide and the corresponding a -propyl, butyl, phenyl, cyclohexyl and chloro-substituted acrylamides, N-di-ethanol acrylamide, N - methyl - N - ethanolacrylamide and the N-propyl-, N-butyl- and N-amyl-N-b -ethanol methacrylamides. The amides may be polymerized alone or with other polymerizable compounds (see Group IV (a)). Specifications 401,435, 648,250, 648,252 and 648,254, [all in Group IV (a)], are referred to. The Specification as open to inspection under Sect. 91 relates to the production of alkylolamides by reacting any acrylyl halide with an alkylolamine in the presence of a diluent which is a solvent for the alkylolacrylamide formed but a non-solvent for the alkylolamine hydrogen halide formed during the reaction. This subject-matter does not appear in the Specification as accepted.