| abstract |
A halogen-containing polyether comprising repeating units of the formula: n n --(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.a --(CHClCF.sub.2 CF.sub.2 O).sub.b n n --(CCl 2 CF 2 CF 2 O) c --(CHFCF 2 CF 2 O) d --(CFClCF 2 CF 2 O) e --(CF 2 CF 2 CF 2 O) f --(I) n wherein a, b, c, d, e and f are each an integer not less than 0 and satisfy the following equations: n n 2≦a+b+c+d+e+f≦200 n n and n n 1≦a+c+d+f, n n which may be prepared by ring-opening polymerizing 2,2,3,3-tetrafluorooxetane in the presence of a polymerization initiator to give a polyether comprising repeating units of the formula: n n --(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.a -- (II) n n wherein a is the same as defined above, and optionally fluorinating and/or chlorinating the polyether (II). |