A unique stepped multifunctionality of perfluorinated aryl compound and its versatile use in synthesizing grafted polymers with controlled structures and topologies
(2423–2433)Journal of Polymer Science Part A: Polymer  Chemistry 49 #11 (2011)
Zhao, Ma, Zhang and Song of Peking University, China, studied astepped multifunctionality of perfluorinated aryl compound by using model reactions between 2,5-dipentafluorophenyl-1,3,4-oxadiazole (FPOx) and mono functional p-cresol at different reaction conditions.  Four distinctively different levels of reactivity were discovered for the para and ortho C-F of FPOx, which could be easily triggered by the reaction temperature in the range of room temperature to 160 °C.  C-F of all levels of reactivity could react quantitatively with nucleophiles (such as phenoxide); and by controlling the reaction conditions, the low-level-reactivity C-F would not interfere with the reaction of C-F of higher reactivity.  Application of this multistepped reactivity of FPOx in quantitative postpolymerization functionalization of polymer was successfully demonstrated.  Stoichiometric amount of p-cresol, with the molar feed ratio of p-cresol in relative to the repeat unit of the polymer of FPOx and 6F-BPA in the range of 1–4, could be readily grafted onto the polymer by simply controlling the reaction temperature. FPOx-based, versatile one-pot synthesis of high molecular-weight grafted polymers with well-controlled structures and topologies were also demonstrated.  (RDC 4/22/2011)