Copolymer composites Copper

The effect of copolymer composition on the rate of the hydroquinone oxidation reaction has been studied using IVI-AA copolymers. Curves of the change of the oxidized hydroquinone concentration as a function of reaction time in the presence of polyampholyte-copper(II) complexes are presented in Fig. 10. An increase in the amount of basic groups in the copolymers leads to an increase in the rate of hydroquinone oxidation. Copolymers in which maleic and methacrylic acids are used as a second comonomer of IVI, exhibit lower activity than IVI-AA. 

The styrene-based random copolymers R-12 and R-13 were prepared by ruthenium and copper catalysts, respectively. For the former copolymer (R-12), the copolymerizations were investigated with various compositions of the two monomers, which revealed that the composition curve is similar to that of conventional radical copolymerizations.205 The latter copolymers (R-13) obtained with R—Br/CuBr have... 

The ATRP of the methacrylate monomers was performed at 60°C in ethanol solutions and in the presence of the catalyst copper(I) chloride/2,2 bipyridyl (Bipy) (Table 1, Entries 1-4). Copolymers P(ME02MA-co-OEGMA) of various chain-lengths and comonomer compositions were prepared and isolated in high yields. After purification, H NMR analysis confirmed that the formed polymers exhibit a terminal cholesterol moiety. Additionally, as previously demonstrated, the molar fraction of OEGMA in the copolymers was found, in all cases, to be almost equal to the fraction of OEGMA in the initial comonomer feed. Furthermore, SEC measurements in THF indicated that all the copolymers are rather well-defined (Table 1, Entries 1-4). 

From the ratio of polyampholyte and metal ion concentrations at which a maximum reaction rate is observed one can ascertain the composition of catalytically active complexes [82]. The effect of [polyampholyte]/[metal ion] composition on Vq at a constant metal ion concentration for several polyampholyte-metal systems is illustrated in Fig. 7. For a majority of the systems the ratio is not higher than 3. These results support the contention that catalytic activity ctm occur only in the presence of free sites in the coordination sphere of a metal ion [83]. An exception to this is the styrene-A/ N-dimethylaminopropylmonoamide of maleic acid/copper(II) complex for which a maximum rate of H2O2 decomposition was found at [polyampholyte]/ [Cu ] = 16 1 and pH = 8.5. Because the isoelectric state of the polyampholyte is attained at pH 6.4 it is unlikely that the compression of the macromolecule coil has affected the complex composition. Apparently it is the presence of hydrophobic styrene units in the copolymer that affects the reaction rate. 

In conclusion, it has been demonstrated that PEG-based macroinitiators are relatively slow initiators in copper mediated living radical polymerization this will result in AB block copolymers with heterogeneous composition but all macroinitiators are eventually transformed into block copolymers. Temperature or solvent has little effect on this, however, the macroinitiator chain length influences the initiator efficiency with shorter chain molecules being faster initiators than longer chain macromolecules. 

Dimethylphenol and 2,6-dimethylphenol could be copolymerized using di- -hydroxo-bis[(WA W A -tetramethylethylenediamine)copper(II)] chloride and tetramethylethylenediamine as a catalyst composition [38]. The conversion of the monomers could be followed by gas chromatography. Characterization of the copolymers by IR revealed that the composition of the copolymer could be controlled by the ratio of monomer feeded. 

Electrical conductivity measurements have been reported on a wide range of polymers including carbon nanofibre reinforced HOPE [52], carbon black filled LDPE-ethylene methyl acrylate composites [28], carbon black filled HDPE [53], carbon black reinforced PP [27], talc filled PP [54], copper particle modified epoxy resins [55], epoxy and epoxy-haematite nanorod composites [56], polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) blends [57], polyacrylonitrile based carbon fibre/PC composites [58], PC/MnCli composite films [59], titanocene polyester derivatives of terephthalic acid [60], lithium trifluoromethane sulfonamide doped PS-block-polyethylene oxide (PEO) copolymers [61], boron containing PVA derived ceramic organic semiconductors [62], sodium lanthanum tetrafluoride complexed with PEO [63], PC, acrylonitrile butadiene [64], blends of polyethylene dioxythiophene/ polystyrene sulfonate, PVC and PEO [65], EVA copolymer/carbon fibre conductive composites [66], carbon nanofibre modified thermotropic liquid crystalline polymers [67], PPY [68], PPY/PP/montmorillonite composites [69], carbon fibre reinforced PDMS-PPY composites [29], PANI [70], epoxy resin/PANI dodecylbenzene sulfonic acid blends [71], PANI/PA 6,6 composites [72], carbon fibre EVA composites [66], HDPE carbon fibre nanocomposites [52] and PPS [73]. 

Some measurements of this property have been made in a range of electrically conducting polymers. These include epoxy resin/polyaniline-dodecylbenzene sulfonic acid blends [38], polystyrene-black polyphenylene oxide copolymers [38], semiconductor-based polypyrroles [33], titanocene polyesters [40], boron-containing polyvinyl alcohol [41], copper-filled epoxy resin [42], polyethylidene dioxy thiophene-polystyrene sulfonate, polyvinyl chloride, polyethylene oxide [43], polycarbonate/acrylonitrile-butadiene-styrene composites [44], polyethylene oxide complexes with sodium lanthanum tetra-fluoride [45], chlorine-substituted polyaniline [46], polyvinyl pyrolidine-polyvinyl alcohol coupled with potassium bromate tetrafluoromethane sulfonamide [47], doped polystyrene block polyethylene [38, 39], polypyrrole [48], polyaniline-polyamide composites [49], and polydimethyl siloxane-polypyrrole composites [50]. 

Fuhrer MS, Nygard J, Shih L, Forero M, Yoon Y-G, Mazzoni MSC, Choi HJ, Ihm J, Louie SG, Zettl A, McEuen PL (2000) Crossed nanotube junctions. Science 288 494 Gelves GA, Lin B, Sundararaj U, Haber JA (2006) Low electrical percolation threshold of sUvct and copper nanowires in polystyrene composites. Adv Funct Mater 16 2423 Gkourmpis T, Svanberg C, Kahappan SK, Schaffer W, Obadal M, Kandiollcu G, Tranchida D (2013) Improved electrical and flow properties of conductive polyolefin blends modificatirai of poly(ethylene vinyl acetate) copolymer/carlxHi black with ethylate—propylene copolymer. Eur Polym 149 1975... 

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