| abstract |
A process for the preparation of homogeneous and cellular polyurethane plastics by the reaction of n (a) organic polyisocyanates; n (b) compounds containing at least 2 Zerewitinoff-active hydrogen atoms and having molecular weights of from 400 to 10,000; n (c) chain extenders, and, optionally, additional n (d) short-chained compounds containing at least 2 Zerewitinoff-active hydrogen atoms and having a molar mass of from 32 to 400, as well as, optionally, n (e) catalysts, blowing agents and other known additives, n is described, which is characterized in that 1,4-3,6-dianhydro-hexites, preferably 1,4-3,6-dianhydro-D-sorbitol and/or 1,4-3,6-dianhydro-D-mannitol, optionally mixed with lower molecular weight compounds, preferably with polyols having a molecular weight of from 62 to 400, particularly preferably butane diol-1,4 are used as the chain extenders. The new chain extenders produce high quality elastomers and foams. |