| abstract |
Bifunctional perfluoropolyether oil is prepared by reacting a perfluoropolyether diol oil of weight average molecular weight 1500-3000 with a chain lengthener selected from diacid chlorides and diisocyanates. Also claimed is perfluoropolyether rubber prepared from derivatised perfluoropolyether diol oil chain lengthened as above in which the OH terminal groups are derivatised with a compound selected from acryloyl chlorides, isocyanate acrylates of formula O=C=N-CH2-O-C(O)-C(R1)=C(R2)(R3) (II) or with a compound of formula O=C=N-[CH2]q-Si[OR4]3 (III), whereafter the derivatised compound is crosslinked under the influence of a suitable catalyst. p = 1-5; R1, R2, R3 = H, lower alkyl (methyl, ethyl, n- or iso-propyl , n-butyl or t-butyl) q = 1-4; and R4 = methyl, ethyl, n-propyl or isopropyl |