Isomeric hexafluoroisopropylidene-linked benzophenone polymers via nickel catalysis

High-performance hexafluoroisopropylidene (HFIP)-linked benzophenone polymers were synthesized by means of Ni(0)-catalyzed polymerization of newly developed bis(aryl triflate) and bis(aryl chloride) monomers. All polymers were amorphous and soluble in most common organic solvents, thus allowing molecular weight determination and spectroscopic analysis. Number-average molecular weights were in the ranges (14-29) x 10(3) g/mol (GPC/RI) and (24-43) x 10(3) g/mol (GPC/MALLS). Polymers exhibited high thermal stabilities with 10% weight loss temperatures ranging from 509 to 573 degrees C and 497 to 559 degrees C in nitrogen and air, respectively. Glass transition temperatures ranged from 161 to 190 degrees C. All polymers were pale yellow to yellow powders with UV absorption in the range 246-304 nm. As with most previously synthesized 2,5-benzophenone polymers, these new materials exhibited poor film-forming properties and produced brittle films when cast from CHCl3. Consequently, a new strategy based on nickel-catalyzed copolymerization was developed to circumvent this problem and to prepare polymers with higher molecular weights, improved film-forming ability, and excellent mechanical properties. The unique structural characteristics of these new HFIP-interrupted poly (paraphenylene) s make them potentially interesting candidates for separations applications as well as for electronics applications, such as nonvolatile organic memory.