Synthesis and Characterization of Amphiphilic Poly(ethylene oxide)‐block‐poly(hexyl methacrylate) Copolymers

Abstract

We describe the preparation of amphiphilic diblock copolymers made of poly(ethylene oxide) (PEO) and poly(hexyl methacrylate) (PHMA) synthesized by anionic polymerization of ethylene oxide and subsequent atom transfer radical polymerization (ATRP) of hexyl methacrylate (HMA). The first block, PEO, is prepared by anionic polymerization of ethylene oxide in tetrahydrofuran. End capping is achieved by treatment of living PEO chain ends with 2‐bromoisobutyryl bromide to yield a macroinitiator for ATRP. The second block is added by polymerization of HMA, using the PEO macroinitiator in the presence of dibromobis(triphenylphosphine) nickel(II), NiBr2(PPh3)2, as the catalyst. Kinetics studies reveal absence of termination consistent with controlled polymerization of HMA. GPC data show low polydispersities of the corresponding diblock copolymers. The microdomain structure of selected PEO‐block‐PHMA block copolymers is investigated by small angle X‐ray scattering experiments, revealing behavior expected from known diblock copolymer phase diagrams.SAXS diffractograms of PEO‐block‐PHMA diblock copolymers with 16, 44, 68 wt.‐% PEO showing spherical (A), cylindrical (B), and lamellae (C) morphologies, respectively.magnified imageSAXS diffractograms of PEO‐block‐PHMA diblock copolymers with 16, 44, 68 wt.‐% PEO showing spherical (A), cylindrical (B), and lamellae (C) morphologies, respectively.

Ultrathin Anatase TiO2 Films with Stable Vesicle Morphology Templated by PMMA‐b‐PEO

“…To this end an amphiphilic block copolymer of poly (methyl methacrylate)-block-poly (ethylene oxide), PMMA-b-PEO, was synthesized and used as a templating agent to prepare TiO 2 ultrathin films with nanovesicle morphology (Scheme 1 in supporting information). [7] We further show that at large wall thickness to diameter ratios the nanovesicle morphology is stable enough to survive calcination at 400°C, at which the amorphous structure is converted to anatase crystalline 2 phase. Compared to the PS-b-PEO block the use of PMMA as the hydrophobic block is advantageous for functional particles.…”

Double-Gyroid Network Morphology in Tapered Diblock Copolymers

“…The hydroxyl-end groups in all three copolymers can be utilized in further polymerization or functionalization steps. 25–27 …”

Nanostructure and Shape Control in Polymer‐Ceramic Hybrids from Poly(ethylene oxide)‐block‐Poly(hexyl methacrylate) and Aluminosilicates Derived from Them

“…The synthesis of PEO-b-PHMA block copolymers by a combination of anionic polymerization and ATRP has been described in a recent publication. [17] Here, we show first results on the synthesis of hybrid materials casted from organic solvents derived from PEO-b-PHMA block copolymers and the metal alkoxides, (3-glycidylpropyl)trimethoxysilane and aluminium sec-butoxide. as received.…”

“…The poly(ethylene oxide)-block-poly(hexyl methacrylate) copolymers (PEO-b-PHMA) were synthesized from commercial ethylene oxide (Fluka) and hexyl methacrylate (Aldrich) according to a recently published polymerization procedure. [17] Three different polymers were used to prepare the hybrids studied in this paper, referred to as T273 (M n ¼ 21 800 g/mol, M w =M n ¼ 1.19, PEO weight fraction: 12%), T55 (M n ¼ 20 960 g/mol, M w =M n ¼ 1.16, PEO weight fraction: 13%) and T37 (M n ¼ 18 750 g/mol, M w =M n ¼ 1.09, PEO weight fraction: 16%). The morphology of these block copolymers in the bulk is a lattice of PEO spheres in a PHMA matrix as expected from diblock copolymer phase diagrams.…”