Articles, especially metal, e.g. aluminium, articles, are bonded with compositions comprising liquid polymerizable vinyl compounds, e.g. styrene, a catalyst and at least one polymer containing the group (-CH2-CCl=CH-CH2-)n, e.g. neoprene. The compositions may also contain other polymeric materials, e.g. polystyrene, hydrophilic monomers, e.g. acrylic acid, cross-linking agents, e.g. divinyl benzene, unsaturated aliphatic nitriles, e.g. acrylonitrile and methacrylonitrile, maleic or fumaric esters, e.g. dimethyl fumarate, unsaturated polyesters, e.g. ethylene glycol maleate, stabilizers, e.g. hydroquinone, dyestuffs and fillers, e.g. finely-divided oxides, carbon black, litharge and metal bronzes, and vulcanizing ingredients. Preferably the catalyst is a redox system. In examples compositions comprising diethanol-p-toluidine are mixed with a paste of benzoyl peroxide in dibutyl phthalate. U.S.A. Specification 2,461,553 is referred to.