| abstract |
The invention relates to a polyurethane, in particular polyurethane elastomeae, using diols and dnsocyanates as well as chain repeaters, which is characterized in that diols or chain extenders optionally have at least one terminal in which X denotes a straight-chain or branched alkylene group having 2 to 12 carbon atoms. The diols or chain extenders are primarily polymers or oligomers of ethylenically unsaturated monomers and preferably have a hydroxyl functionality in the vicinity of 2, preferably from 1.9 to 2.1.n n n The invention further relates to a process for free-radical polymerization, which is characterized in that ethylenically unsaturated monomers in the presence of azobis-N, N'-isobutyric acid hydroxylalkylamides of the general in which X represents a straight-chain or branched alkylene group having 2 to 12 carbon atoms, are polymerized. |