| abstract |
The invention relates to a shape memory polymer, to a process for its preparation, to a process for its programming and to its use. The inventive shape memory polymer has at least two switch segments with different transition temperatures (Ttrans,1, Ttrans,2), such that the polymer, depending on the temperature, as well as a permanent shape (PF), can assume at least two temporary shapes (TF1 , TF2). The first switch segment is based essentially on a polyester of the general formula (I) where n = 1...6 or a copolyester of the general formula (I) with different n or a derivative thereof. The second switch segment is based essentially on a polyether of the general formula (II) where m = 1...4 or a copolyether of the general formula II with different m or a derivative thereof. |