Use of an Immobilized/Soluble Hybrid ATRP Catalyst System for the Preparation of Block Copolymers, Random Copolymers, and Polymers with High Degree of Chain End Functionality

Abstract

An immobilized/soluble hybrid catalyst system (CuBr/PS8-dMbpy)/(CuBr2/Me6TREN) for atom transfer radical polymerization (ATRP) was applied to the preparation of polymers exhibiting various architectures. Polymers with high degree of halogen chain end functionality (∼85%) were obtained using the hybrid catalyst system ensuring high efficiency of chain extension reactions through successive monomer addition, affording block (tapered) copolymers. Use of the immobilized catalyst also allowed the synthesis of block copolymers using macroinitiators synthesized by other mechanisms, such as poly(dimethylsiloxane). In the copolymerization of MMA and n-butyl acrylate, the molecular weight, molecular weight distribution, kinetics, and reactivity ratios were similar to those in a conventional homogeneous ATRP, indicating the chemical nature of the polymerization intermediates are similar for both systems. These examples demonstrate the broad applicability of the hybrid catalyst system to various ATRP processes.

Synthesis and characterization of sugar-based methacrylates and their random copolymers by ATRP

“…On the other hand, the rest protons of methylene and methine groups of sugar methacrylates were detected between 3.71 and 4.52 ppm, which confirmed the presence of methacrylate moieties on the monosaccharides. Compositions of the random copolymers could be determined from the integration ratio of methoxy protons (d at 3.62 ppm) to that of the H-1 protons (t at 5.63-5.91 ppm) [51]. The values for the composition determinations were about 94.1-97.8% and agreed well with feeding ratio (MMA:total monomer = 93.75:100).…”

“Green” Atom Transfer Radical Polymerization: From Process Design to Preparation of Well-Defined Environmentally Friendly Polymeric Materials

“…Alternatively, a small amount of a very active soluble catalyst (e.g., Cu I Br/Me 6 TREN), together with a less active supported catalyst, mediates ATRP very efficiently. [172][173][174] The three different radical deactivation mechanisms in ATRP mediated by supported catalysts are depicted in Figure 4. 171 Cu I Br/HMTETA catalyst that was supported on silica gel and packed in a column was used in a continuous ATRP process.…”

Graft Polymerization of Dimethylacrylamide onto Polysilsesquioxane Containing Mercapto Groups

“…The contact angle of PMPSQ-g-PDMAA containing 7.8 monomer units to one mercapto group (Table I, Run 5) obviously decreased to be 18 . In the case of PMPSQ-g-PDMAA containing 11.3 monomer units (Table I, Run 6), the angle was 12 . Thus, the angle decreased with the increase of contents of the hydrophilic monomer units, although the accuracy of the values of PMPSQ-g-PDMAAs might be governed by an experimental error.…”

“…2,3 Furthermore, the expectation is supported by the recent studies on the introduction of polymeric components onto the related polysiloxane compounds such as silica, zeolite, and clay to modify or improve the properties. [4][5][6][7][8] For the effective grafting, the living polymerization techniques via radical species such as atom transfer radical polymerization process [9][10][11][12] and the use of photoiniferter 13 are appropriately utilized in the recent investigations. These living polymerization techniques contribute to minimize the formation of free chains, control the chain length, and the easy formation of block copolymer chains.…”