The syntheses of aromatic oxazolyl and carboxyl functionalized polymers using 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole in atom transfer radical polymerization reactions

The syntheses of 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole and its utility as an aromatic oxazolyl functionalized initiator precursor and functionalizing agent for the preparation of oxazolyl functionalized polymers by atom transfer radical polymerization methods are reported. The quantitative chemical transformation of the oxazoline group of the respective oxazolyl chain end functionalized polymers by successive hydrolysis reactions provides the corresponding well defined aromatic carboxyl chain end functionalized polymers. [Display omitted] ► The syntheses of α-oxazolyl and α,ω-bis(oxazolyl) polystyrenes by ATRP. ► The use of 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole in ATRP. ► α,ω-Bis(oxazolyl) polystyrene by post ATRP chain end functionalization reactions. ► ATRP chain end functionalization reactions without isolation of polymer precursor. ► The syntheses of α-carboxyl and α,ω-bis(carboxyl) polystyrenes by ATRP. The syntheses of oxazolyl functionalized polymers using 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole in atom transfer radical polymerization (ATRP) reactions are reported. A new oxazolyl initiator system was generated in situ by the atom transfer radical addition (ATRA) reaction of (1-bromoethyl)benzene with 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole and employed as the oxazolyl functionalized initiator for the polymerization of styrene by ATRP methods to produce well defined α-oxazolyl functionalized polystyrene. The polymerization kinetic data for the synthesis of α-oxazolyl functionalized polystyrene shows that the polymerization process follows first order rate kinetics with respect to monomer consumption. The number average molecular weights (Mn=0.61×103–9.8×103g/mol) of the α-oxazolyl functionalized polymers increased linearly with percentage monomer conversion and polymers with narrow molecular weight distributions (Mw/Mn=1.22–1.51) were obtained. The polymerization processes were monitored by gas chromatographic analyses to determine the extent of monomer consumption as a function of time. α,ω-Bis(oxazolyl) functionalized polystyrene was prepared by a new, controlled/living, post ATRP chain end functionalization reaction which involves the direct addition of 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole to the ω-terminus of α-oxazolyl functionalized polystyrene, without the isolation and purification of the functionalized polymeric precursor. The