Polyurethane material with a high temperature resistance

A process for preparing a polyurethane material, said process consisting of forming a reaction mixture consisting of:

• a) di- and/or polyisocyanates,
• b) compounds having isocyanate-reactive hydrogen atoms,
• c) compounds comprising at least one terminal carbon-carbon double bond,
• d) optionally a catalyst to hasten a urethane reaction,
• e) optionally a free-radical initiator, and
• f) optionally further auxiliary and added-substance materials,
• curing the reaction mixture to obtain the polyurethane material, and
• optionally free-radical polymerizing the compounds (c) comprising at least one terminal carbon-carbon double bond,
• wherein:
• the compounds (b) having isocyanate-reactive hydrogen atoms contain on average not less than 1.5 isocyanate-reactive hydrogen groups per molecule,
• a double bond density of the compounds (c) is not less than 21% and the compounds (c) have no isocyanate-reactive groups, wherein the double bond density is calculated by dividing a molecular mass of the at least one terminal carbon-carbon double bond (as determined by a molecular formula —CH═CH2) by a total molecular mass of the compounds (c),
• a double bond functionality of the compounds (c) is greater than 1, and
• an equivalence ratio between isocyanate groups of the di- and/or polyisocyanates (a) and the isocyanate-reactive hydrogen atoms of the compounds (b) is in the range from 0.8 to 2.