Synthesis, self-assembly, and thermosensitivity of amphiphilic POEGMA-PDMS-POEGMA triblock copolymers

Abstract

In this article, the synthesis and self‐assembly of a novel well‐defined biocompatible amphiphilic POEGMA‐PDMS‐POEGMA triblock copolymer were studied. The copolymer was synthesized by atom transfer radical polymerization of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) using α,ω‐dibromo polydimethylsiloxane macroinitiator (Br‐PDMS‐Br). Br‐PDMS‐Br was synthesized through the esterification of α,ω‐hydroxypropyl polydimethylsiloxane and 2‐bromoisobutyryl bromide. The structures of the copolymers were confirmed by proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The copolymers showed reversible aggregation in response to temperature cycles with a lower critical solution temperature (LCST) between 61 and 66 °C, as determined by ultraviolet‐visible spectrophotometry and dynamic light scattering. The LCST values increased in proportion to the length of the hydrophilic block and were lower than that of the POEGMA homopolymer. The self‐assembly behavior of the copolymers in aqueous solution was investigated by fluorescence spectroscopy and transmission electron microscopy. The critical micelle concentration value (1.08–0.26 10−6 mol L−1) decreased as the length of the POEGMA chain increased. The POEGMA‐PDMS‐POEGMA copolymers can easily self‐assemble into spherical micelles in aqueous solution. Such biocompatible block copolymers may be attractive candidates as ‘‘smart'' thermo‐responsive drug delivery systems. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2684‐2691

Well-Organized Meso-Macroporous TiO2/SiO2Film Derived from Amphiphilic Rubbery Comb Copolymer

“…The shape and size of PDMS-g-POEM comb copolymer with a molecular weight of 14,000 gmol -1 in ethanol (1 wt%) are comparable to those reported by Wang et al 29 ; these authors reported that a POEGMA 11.6 -PDMS 11 - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 14 POEGMA 11.6 triblock copolymer with a molecular weight of 9400 gmol -1 could self-assemble into spherical single micelles with a diameter of approximately 100 nm in aqueous solution (0.5 mg mL -1 ).…”

“…The self-arrangement of PDMS-g-POEM comb copolymer into uniform spherical micelles in a polar solvent such as ethanol was proved by the EF-TEM image shown in [26][27][28][29] Micelle morphology is largely dependent on experimental parameters such as the molecular weight of the polymers, relative chain length ratio of each block, type of medium, and concentration. The shape and size of PDMS-g-POEM comb copolymer with a molecular weight of 14,000 gmol -1 in ethanol (1 wt%) are comparable to those reported by Wang et al 29 ; these authors reported that a POEGMA 11.6 -PDMS 11 - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 14 POEGMA 11.6 triblock copolymer with a molecular weight of 9400 gmol -1 could self-assemble into spherical single micelles with a diameter of approximately 100 nm in aqueous solution (0.5 mg mL -1 ).…”

A novel thermosensitive triblock copolymer from 100% renewably sourced poly(trimethylene ether) glycol

“…100% renewably sourced PO3G is a novel bio‐based polyether glycol, and this kind of renewable polyol with low glass transition temperature ( T g ) and thermal stability was allowed to react with 2‐bromoisobutyryl bromide to yield Br‐PO3G‐Br macroinitiator by esterification following literature procedures . The chemical structure of the resulting Br‐PO3G‐Br was characterized by 1 H NMR, GPC, and FTIR measurements.…”

“…The CMC of triblock copolymer samples was determined by the fluorescence probe technique using pyrene as a fluorescence probe according to our previous works …”

“…Statistical copolymers [P(MEO 2 MA‐ stat ‐OEGMA)] of 2‐(2‐methoxyethoxy) ethyl methacrylate(MEO 2 MA) and oligo(ethylene glycol) methacrylate (OEGMA) were synthesized by Lutz and coworkers, where the LCST values of these copolymers were tuned over a temperature range 28–65 °C. In our previous study, POEGMA‐ b ‐polydimethylsiloxane‐ b ‐POEGMA (POEGMA‐ b ‐PDMS‐ b ‐POEGMA) triblock copolymers were synthesized as a new thermosensitive, biocompatible, and amphiphilic block polymer through atom transfer radical polymerization (ATRP) …”