Syntheses of [alpha]-bis(4-aminophenyl)- and [alpha],[omega]-tetrakis(4-aminophenyl)- functionalized polymers using 1,1-bis(4-aminophenyl)ethylene in atom transfer radical polymerization reactions

• Published in: Polymer international 2014-05, Vol.63 (5), p.876
• Main Authors: Summers, Gabriel J, Ndawuni, Mzikayise P, Summers, Carol A
• Format: Article
• Language: English
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/pi.4614

The preparation of a symmetrically disubstituted 1,1-diphenylethylene derivative, 1,1-bis(4-aminophenyl)ethylene, by the Wittig reaction as well as the preparation of primary amine chain-end-functionalized polymers using that derivative in atom transfer radical polymerization (ATRP) reactions are reported. A new primary diamine initiator system was generated in situ by the atom transfer radical addition reaction of (1-bromoethyl)benzene with 1,1-bis(4-aminophenyl)ethylene in the presence of copper(I) bromide/2,2'-bipyridyl as the catalyst system and employed as the primary diamine-functionalized initiator for the polymerization of styrene by ATRP methods to produce well-defined [alpha]-bis(4-aminophenyl)-functionalized polystyrene. The polymerization kinetic data for the synthesis of [alpha]-bis(4-aminophenyl)-functionalized polystyrene shows that the polymerization process followed first-order rate kinetics with respect to monomer consumption. The number-average molecular weights (Mn=1.1×103 to 13.14×103 gmol-1) of the [alpha]-bis(4-aminophenyl)-functionalized polymers increased linearly with percentage monomer conversion and polymers with narrow molecular weight distributions (Mw/Mn=1.1-1.25) were obtained. The polymerization processes were monitored using gas chromatographic analyses to determine the extent of monomer consumption as a function of time. In addition, [alpha],[omega]-tetrakis(4-aminophenyl)-functionalized polystyrene was prepared by a new, controlled/living, in situ post-ATRP chain-end functionalization reaction which involved the direct addition of 1,1-bis(4-aminophenyl)ethylene to the [omega]-terminus of [alpha]-bis(4-aminophenyl)-functionalized polystyrene, without the need for the isolation and purification of the polymeric precursor. The organic precursor compounds, the primary diamine-functionalized 1,1-diphenylethylene derivative and the functionalized polymers were characterized using 1H NMR, 13C NMR and Fourier transform infrared spectroscopy, size exclusion chromatography, thin-layer chromatography and non-aqueous titration measurements. © 2013 Society of Chemical Industry [PUBLICATION ABSTRACT]