Synthesis of poly(ethylene oxide)-block-poly(methyl methacrylate)-block-polystyrene triblock copolymers by two-step atom transfer radical polymerization

A simplified electrochemically mediated ATRP synthesis of PEO-b-PMMA copolymers

“…The rate of activation of a bromo-terminated polymethacrylate chain end is faster than the activation of a 2-bromoisobutyrate PEO chain end. [39,[77][78][79][80][81][82]Typically, halogen exchange procedures [23,24,[35][36][37][38][39] are employed to solve this problem, but they can not be used for systems with low concentrations of catalyst, because of poor initiation efficiency. Motivated by the very good control over the polymerization that is attainable with high amounts Cu (ca.…”

“…Motivated by the very good control over the polymerization that is attainable with high amounts Cu (ca. 1,000-30,000 ppm) [23,24,29,[35][36][37][38][39] we initially set out to achieve similar levels of control using only 50 ppm of Cu II /L in solution, following the eATRP procedure under potentiostatic conditions, which requires a three electrode systema Pt mesh working electrode (WE), a Pt mesh counter electrode (CE) (separated from the reaction media using methylated cellulose gel), and a saturated calomel electrode (SCE) reference electrode (RE). In addition, to simplify the procedure, eATRP was carried out under galvanostatic conditions, which only requires a Pt mesh working cathode and an Al wire counter/sacrificial anode.…”

“…1,00030,000 ppm, were used. [23,24,[35][36][37] Triblock copolymers with narrow MWD (M w /M n = 1.111.30) were prepared using a difunctional PEO macroinitiator but also required a high concentration of catalyst, at least 10,500 ppm. [23,38,39] Recently, new ATRP procedures with low concentration of Cu-based catalysts were developed.…”

Surface-initiated atom transfer radical polymerization from TiO2 nanoparticles

“…Then, the water soluble polymers such as POEM and PSSA were grafted from the TiO 2 nanoparticles via surface-initiated ATRP. In order to avoid cleavage of the polymer chains, as in the case of derivatizations of poly(ethylene glycol) (PEG), the reaction was carried out at 0 8C in CH 2 Cl 2 in the presence of TEA and DMAP [21][22][23]. Fig.…”

Synthesis and self-assembly of poly(ethylene oxide)-b-poly (2-hydroxyethyl methacrylate)

“…In particular, HEMA can be successfully polymerized with the molecular weight distributions ranging from 1.1 to 1.5 in both silyl-protected [5] and unprotected forms [6][7][8][9][10]. PEO-Br macroinitiator has been widely used in atom transfer radical polymerization [11][12][13]. Thus PEO-b-PHEMA double hydrophilic block copolymer can be synthesized using this method.…”