Graft poly /styrene

Poly(AB) is active [103] in the UV induced polymerization of styrene in diox-ane solution. The solvent fiactionation of the resulting polymeric product has been proved to be constituted by a small amount of linear and graft poly(styrene), the main product being a crosslinked iwlymer, according to the occurrence of termination reactions involving polymer-bound growing chain and substituted benzyl radicals. 

Most of the commonly used membranes used in DMFC exhibit acceptable performance stability after thousands of hours under steady-state operation, including perfluorinated sulfonic acid, PTFE-co-HFP radiation-grafted poly- styrenes, and sPAE [85]. However, membrane durability results under unsteady-state operation are stUl scarce. Siroma et al. [114] have shown that a significant fraction of Nation dissolved after 1 week of DMFC operation with methanol solution. 

Membranes having grafted poly(styrene sulfonic acid) and three different backbone polymers, and low-density polystyrene, poly(tetrafluoroethylene), and a copolymer of tetrafluoroethylene and hexafluoroethylene showed similar conductivities to those found for Nation and Dow membranes [7]. However, the oxidative stability of these membranes was poor. Only poly(tetrafluoroethylene) showed some promise as a candidate material. The stability of these membranes in fuel cell systems for applications above 60-70°C was not investigated. 

Patel, R., Im, S.J., Ko, Y.T., Kim, J.H., Min, B.R. (2009) Preparation and characterization of proton conducting polysulfone grafted poly(styrene sulfonic acid) polyelectrolyte membranes. Journal of Industrial and Engineering Chemistry, 15, 299-303. 

A similar expression can be deduced for monomer . Figure 3.4 represents the partitioning of styrene and methyl methacrylate between monomer droplets and latex particles consisting of poly(styrene-co-methyl methacrylate) and polybutadiene-graft-poly(styrene-co-methyl methacrylate), respectively (Aerdts et al, 1993). As is shown in Figures 3.4 and 3.5, the experimental data can be described by this model, that is, by Equation 3.13. Figure 3.5 shows the mole fraction of methyl methacrylate in the latex particles as a function of the mole fraction of methyl methacrylate in the monomer droplets. Here again, the model can describe the experimental results extremely well. 

Figure 3.5 Experimentally determined fractions of methyl methacrylate in the droplet phase as a function of the fraction of methyl methacrylate in different latex particles. Methyl methacrylate and styrene in polybutadiene (open circles), SMMA-free (open squares), SMMA-graft (open triangles) from polybutadiene-graft-poly(styrene-co-methyl methacrylate) latex particles, while the closed squares represent a poly(styrene-co-methyl methacrylate) latex swollen with styrene and methyl methacrylate. The solid line gives the theoretical prediction according to Equation 3.13.

A review covers the preparation and properties of both MABS and MBS polymers (75). Literature is available on the grafting of methacrylates onto a wide variety of other substrates (76,77). Typical examples include the grafting of methyl methacrylate onto mbbers by a variety of methods chemical (78,79), photochemical (80), radiation (80,81), and mastication (82). Methyl methacrylate has been grafted onto such substrates as cellulose (83), poly(vinyl alcohol) (84), polyester fibers (85), polyethylene (86), poly(styrene) (87), poly(vinyl chloride) (88), and other alkyl methacrylates (89). 

Thermoplastic elastomers are often multiphase compositions in which the phases are intimately dispersed. In many cases, the phases are chemically bonded by block or graft copolymerization. In others, a fine dispersion is apparentiy sufficient. In these multiphase systems, at least one phase consists of a material that is hard at room temperature but becomes fluid upon heating. Another phase consists of a softer material that is mbberlike at RT. A simple stmcture is an A—B—A block copolymer, where A is a hard phase and B an elastomer, eg, poly(styrene- -elastomer- -styrene). 

Grafting of 2-methyloxazoline onto chloromethylated polystyrene beads in benzonitrile at 110 °C gave graft copolymers, which were hydrolyzed to poly(styrene-g-ethylenimine) and useful as a chelating resin370. ... 

Virklund, C., Nordstrom, A., Irgum, K. (2001). Preparation of porous poly(styrene-co-divinylbenzene) Monoliths with controlled pore size distributions initiated by stable free radicals and their pore surface functionalization by grafting. Macromolecules 34, 4361-... 

A combination of TEMPO living free radical (LFRP) and anionic polymerization was used for the synthesis of block-graft, block-brush, and graft-block-graft copolymers of styrene and isoprene [201]. The block-graft copolymers were synthesized by preparing a PS-fo-poly(styrene-co-p-chloromethylstyrene) by LFRP [Scheme 110 (1)], and the subsequent re-... 

ATRP and grafting from methods led to the synthesis of poly(styrene-g-tert-butyl acrylate)-fr-poly(ethylene-co-butylene)-fr-poly(styrene-g-ferf-butyl acrylate) block-graft copolymer [203]. ATRP initiating sites were produced along the PS blocks by chloromethylation as shown in Scheme 112. These sites then served to polymerize the ferf-butyl acrylate. The poly(ferf-butyl acrylate) grafts were hydrolyzed to result in the corresponding poly(acrylic... 

Gauthier and M oiler [4] described in 1991 the use of anionic polymerization and grafting techniques to prepare poly(styrenes) with a dendritic structure. Styrene is well suited to be incorporated into a synthetic scheme aimed at producing... 

DENDRIGRAFT (ARBORESCENT)-POLY(STYRENE)-GRAFT-POLY(ISOPRENE) COPOLYMERS... 

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