Inventors:
Paul N. Chen - Gillette NJ
Morton Glick - Summit NJ
Rohitkumar H. Vora - Westfield NJ
Michael Jaffe - Maplewood NJ
Assignee:
Hoechst Celanese Corp. - Somerville NJ
International Classification:
C08L 7906, C08L 7908
Abstract:
A miscible blend comprising from about 5 to about 95 weight percent of a polybenzimidazole and from about 95 to about 5 weight percent of a polyamide-imide having fluorine-containing linking groups, total weight percent of the two polymers being 100. A process for preparing the blends comprises dissolving in a mutual solvent from about 5 to about 95 weight percent of the aromatic polybenzimidazole to about 95 to about 5 weight percent of the polyamide-imide having fluorine-containing linking groups, based on the total weight of those polymers and subsequently evaporating the solvent, thereby producing a dried blend of a polybenzimidazole and a polyamide-imide having fluorine-containing linking groups. The blends, particularly in the form of films, fibers or fibrets, may be post-treated with heat or sulfuric acid in order to minimize their shrinkage when subsequently subjected to heat and in order to increase their resistance to solvents and acid. The polyamide-imides having fluorine-containing linking groups are prepared by forming the polycondensation product of one or more aromatic diamines, one or more trifunctional acid anhydride monomers, and one or more tetrafunctional aromatic dianhydrides, at least one of said monomers containing the group ##STR1## linking two aromatic moieties, wherein R is CF. sub.