Effect of Solvent on the Activation Rate Parameters for Polystyrene and Poly(butyl acrylate) Macroinitiators in Atom Transfer Radical Polymerization

Abstract

The activation rate parameters of polystyrene (k S act) and poly(butyl acrylate) (k BA act) macroinitiators in ATRP catalyzed by CuBr/4,4‘-di-n-heptyl-2,2‘-bipyridine have been determined at 110 °C using a combination of nitroxide exchange reactions with HPLC analysis. The method is based on exchange of the bromide end group with a hydroxy-TEMPO end group. The depletion of the macroinitiator is monitored as a function of time. The method is applicable in different solvents, which implies the possibility to investigate the effect of solvent characteristics. Solvent polarity has a negative influence on k S act and a positive effect on k BA act. The ability of the solvent to act as ligand in the copper complex hampers the activation process for both macroinitiators, while the presence of hydroxy groups in the solvent increases both activation rate parameters.

Synthesis and Characterization of Triarylamine-Based Block Copolymers by Combination of C-N Coupling and ATRP for Photorefractive Applications

“…In this study, it was demonstra- ted that the activation rate decreased with decreasing of the solvent polarity. Similar effect has been also reported in other systems [25][26][27]. Therefore the mixture solvent (1/1, v/v) of anisole, a good solvent for PBTPA-MI, and NMP, a solvent with relatively high polarity was used.…”

Synthesis and characterisation of hydroxyl end-capped telechelic polymers with poly(methyl methacrylate)-block-poly(n-butyl acrylate) backbones via atom transfer radical polymerisation

“…Therefore, it is possible to separate polymers according to molar mass, chemical composition, and chain or chain-end functionality with GPEC. Recently, polymers with only one hydroxyl end group difference (i.e., PBA and PBA-OH) have been successfully separated with this technique [12,51]. In our study, GPEC was used to monitor the end-group modification process of HO-PMMA-b-PBA-Br (Fig.…”

Towards understanding monomer coordination in atom transfer radical polymerization: synthesis of [CuI(PMDETA)(π-M)][BPh4] (M = methyl acrylate, styrene, 1-octene, and methyl methacrylate) and structural studies by FT-IR and 1H NMR spectroscopy and X-ray crystallography

“…½Cu I ðPMDETAÞ þ ½BPh À 4 , for which the counter-ion does not compete with monomer for coordination to Cu I , was thus studied in an effort to address the side reaction of monomer coordination to the Cu I catalyst. Third, correlating reaction parameters including activation, deactivation, initiation, overall reaction rate constants, and evolution of molecular weight distribution [41][42][43][44][45][46][47][48] with catalyst, alkyl halide, and monomer structure, solvent composition and temperature should ultimately lead to the development of more active catalysts and are crucial to any future developments of ATRP [49][50][51][52][53][54]. This paper will address the nature of the bonding in these Cu I complexes, and subsequent publications will address the quantification of this coordination process under various conditions and with Cu I (PMDETA)Br, the effect that coordination has on the reactivity of the monomer, and the performance of the catalyst in polymerization.…”