Abstract: Polymer-modified bituminous compositions containing 0.5 to 20% by weight of polymer components, where 20 to 100% by weight of the polymer added is polyalkyl(meth)acrylate, which in synthesized from 50 to 99.8% by weight from C.sub.6 to C.sub.28 alkyl(meth)acrylates, 0.2 to 20% by weight from polymerizable carboxylic acids and/or sulfonic acids and 0 to 49.8% by weight from one or more other polymerizable, in particular nitrogen-containing compounds. Through the addition of reactive metal compounds, bituminous mixtures with improved elastic recovery, for example ranging from >50% to about 90%, with low temperature flexibility and high thermal stability are obtained.

Abstract: What is disclosed is the polymerization of free radically-polymerizable compounds such as acryl compounds and methacryl compounds under the influence of light having a wave length from 200 nm to 500 nm in the presence of a symmetric azo compound comprising tertiary aliphatic hydrocarbon groups each having a molecular weight of 71 to 97 bound to the azo group, whereby the polymerization temperature can be maintained under 100.degree. C. by regulation of the light intensity.

Abstract: Symmetric azo-bis-mercapto compounds of the formula ##STR1## wherein R.sub.1 and R.sub.2 are methyl or ethyl, R.sub.3 and R.sub.4 are the same or different alkylene having 1 to 4 carbon atoms, and n is 0 or 1, and a method for forming block copolymers of vinyl monomers in a two-step process employing such compounds as polymerization initiators.