FLUORINATED POLYURETHANES CONTAINING POLYOXYPERFLUOROALKYLENE BLOCKS ANDHAVING IMPROVED MECHANICAL PROPERTIES

摘要

Polyurethanes having low glass transition temperatures and good mechanical properties may be made from polyoxyperfluoroalkylene blocks of rubber-like nature and rigid segments derived from low molecular weight cycloaliphatic diols, and from aliphatic or cycloaliphatic or aromatic diisocyanates. The number of rigid segments is higher than the number of polyoxyperfluoroalkylene blocks. Such polyurethanes have a glass transition temperature lower than -80.degree.C, a tensile strength higher than 30 kg/cm2, a hardness between 50 Shore A and 75 Shore D, and good thermoforming characteristics.