Acrylic acid esters are manufactured by reacting secondary or tertiary butyl or amyl alcohols with acrylic acid, preferably in the presence of a dehydrating agent, with an acrylic acid halide or with acrylic anhydride. In examples, acrylyl chloride is reacted in the presence of calcium carbonate with: (1) butanol-2 to produce sec.-butyl acrylate; (2) tert.-butyl alcohol to produce tert.-butyl acrylate; (3) pentanol-2 to produce sec.-amyl acrylate; (4) tert.-amyl alcohol to produce tert.amyl acrylate. Diethylcarbinol and methylisopropylcarbinol are also specified as starting materials. Polymerization products are manufactured by subjecting to polymerization, under the action of heat, irradiation or both, acrylic acid secondary or tertiary butyl or amyl esters, alone or in admixture with one another or with other substances, e.g. other esters of acrylic acid, esters of methacrylic acid, vinyl esters, ethers and ketones, acrylic and methacrylic acid halides, amides, nitriles and anhydrides, isoprene, butadiene or styrene. The polymerization may be effected in the presence of polymerization catalysts, e.g. organic or inorganic peroxides, oxygen or ozone, and may be carried out on the monomer alone, or dissolved in a solvent, which may be a non-solvent for the polymer, or suspended in a non-solvent, e.g. water, with or without emulsifying agents. The products may be obtained in the form of sheets, blocks or rods by effecting polymerization in a mould, preferably under pressure or in the presence of a terpene hydrocarbon to prevent the formation of bubbles. Useful articles may also be prepared from the polymers by moulding, turning or extrusion. The products may also be used for adhesives, electrical insulators or interlayers in laminated glass, or as coating-compositions, which may be obtained by polymerization in solution, with the addition, if desired, of pigments, fillers and colouring materials before, during or after polymerization. For moulding there may be added plasticizers, e.g. the ester of phthalic acid, camphor or acetone, whilst mould lubricants, e.g. mineral oils, neat's foot oil, stearic or oleic acid, may be used directly in the mould or incorporated in the polymer. The polymerization of the products of the examples above is described.