Abstract: The invention relates to a foamable bead polymer consisting of (meth)acrylonitrile, (meth)acrylic acid, copolymerizable latent blowing agents and optionally (meth)acrylic esters, the preparation thereof by suspension polymerization and the use thereof for producing foams. Such a bead polymer makes it possible, for example, to carry out in-mould foaming in a simple way and thus produce products having the shape of the desired workpiece directly. These workpieces are highly suitable as components in space, air, water and land vehicles and for other construction elements.