Synthesis of polyesters-perfluoropolyethers block copolymers - 3. Use of various telechelic perfluoropolyethers

Multiblock-(A-B)n-copolymers containing polyester segments together with perfluoropolyether (PFPE) segments have been prepared by polymerizing dimethyl terephthalate (DMT), or an equimolar mixture of DMT and dimethyl isophthalate (DMI), with ethylene glycol (EG) in the presence of different telechelic perfluoropolyethers in various amounts (5-30 wt%), using Tl(OBu)4 as the catalyst. Fomblin ZDEAL (a-COOCH3 terminated PFPE), Fomblin ZDOL (a PFPE having-CH2OH terminal groups), and Fomblin ZDOLTX (a PFPE having-CH2O(CH2CH2O)yH terminal groups) were used as telechelic PFPEs. Fomblin ZDOLTX gave the best results: the highest yield in block copolymer (less sensitive to hydrolysis with respect to block copolymers prepared from the other PFPEs), a longer average length of polyester segments, and a relatively low fraction of PFPE lost by distillation during polymerization. © 1992 Springer-Verlag.