ATRP Synthesis of Amphiphilic Random, Gradient, and Block Copolymers of 2-(Dimethylamino)ethyl Methacrylate and n-Butyl Methacrylate in Aqueous Media

Abstract

Amphiphilic random, gradient, and block copolymers of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and n-butyl methacrylate (BMA) were synthesized by atom transfer radical polymerization (ATRP) in water/2-propanol mixtures using a methoxy-poly(ethylene glycol) (MPEG) (M(n) = 2000) macroinitiator. Kinetic studies indicate that the copolymerization is well controlled with molecular weights increasing linearly with conversion. Copolymers with molecular weights up to M(n) = 34000 and low polydispersities (M(w)/M(n) = 1.11-1.47) were prepared. The reactivity ratios were calculated for the copolymerizations catalyzed by CuBr/bpy, (r(DMAEMA) = 1.07, r(BMA) = 1.24). The thermosensitivity and aggregation properties of the random, gradient, and block copolymers significantly depended on the architecture of the copolymers. The lower critical solution temperature of MPEG-b-PDMAEMA(84) was 38 degrees C (5 wt % in water).

In-vitro cytotoxic activities of poly(2-ethyl-2-oxazoline)-based amphiphilic block copolymers prepared by CuAAC click chemistry

“…Typically,propargyl alcohol (PA,210,89 µL,3,57 mmol) and LA (5 g, 34,69 mmol) were added in a flask with a magnetic stirring bar, and a solution of Sn(Oct) 2 (9,64 µL, 0,03 mmol) in 5 mL of toluene was introduced using a syringe. The reactive mixture was deaerated with nitrogen and then immersed in a thermostated oil bath at 120°C for 5 h. After removing the solvent under reduced pressure, the residue was dissolved in dichloromethane and precipitated in cold methanol.…”

Synthesis of Stimuli-responsive, Water-soluble Poly[2-(dimethylamino)ethyl methacrylate/styrene] Statistical Copolymers by Nitroxide Mediated Polymerization

“…These results demonstrated the DMAEMA/styrene statistical copolymers with 89 and 96 mol% DMAEMA possessed similar pH sensitivity to that expected for PDMAEMA homopolymer. DMAEMA has been incorporated into various block copolymers to obtain pH and/or temperature induced micelles in aqueous solutions because of the sensitivity to both pH and temperature of PDMAEMA [8,12,15,61] In Figure 10, the R h of the block copolymer as a function of temperature was compared to its macroinitiator (DMAEMA/S-80/20, F DMAEMA = 81 mol%, M n = 11.2 kg mol −1 ) and the statistical polymers with similar composition and molecular weight as the second block (DMAEMA/S-95/5, F DMAEMA = 96 mol%, M n = 9.6 kg mol…”

“…To achieve these goals with relatively robust experimental conditions, controlled radical polymerization (CRP) techniques like atom transfer radical polymerization (ATRP), reversible addition-fragmentation transfer (RAFT) and nitroxide mediated polymerization (NMP) have emerged [13]. For DMAEMA specifically, ATRP [14][15][16] and RAFT [9,17,18] have been successfully applied to obtain well-defined (co)polymers. NMP, being a solely thermal process, does not involve metal catalysts that ATRP requires or bimolecular exchange with sulfur-based agents as in RAFT, which is potentially advantageous for synthesis of non-cytotoxic polymers for biomedical applications [19][20][21] or electronic applications where metal contamination is undesirable [21].…”

Preparation and self-assembly behavior of polystyrene-block-poly (dimethylaminoethyl methacrylate) amphiphilic block copolymer using atom transfer radical polymerization

“…ATRP is an excellent and well-established method for obtaining block copolymers using simple experimental protocols and a large variety of the available monomers, especially for preparation of amphiphilic block copolymers with well-defined architecture and narrow molecular weight distribution [43][44][45][46][47][48][49][50]. This example demonstrates, in the best way, the features that must be considered for a successful employment of ATRP in block copolymer synthesis.…”