01908nas a2200169 4500008004100000022001400041245010100055210006900156260007100225300001400296490000700310520122200317100002301539700002001562700002601582856013001608 2005 eng d a0897-475600aNoncovalent and nonspecific molecular interactions of polymers with multiwalled carbon nanotubes0 aNoncovalent and nonspecific molecular interactions of polymers w a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN a3389-33970 v173 a

Polymer composites containing variable amounts of multiwalled carbon nanotubes (MWNTs) have been prepared using solution dispersion and melt-shear mixing. Various polymer composites with 1 wt % MWNTs have been found to dissolve homogeneously in organic solvents. The amount of polymer coated or wrapped MWNTs dissolved in the solution was quantified using UV-vis absorbance at 500 nm and the concentration ratio of [MWNTs](solution)/[MWNTs](composite) was close to 1. A nonspecific polymer adsorption through multiple-weak molecular interactions of CH groups with MWNTs in the composites has been identified through FTIR spectroscopy. The composites of polybutadiene with different wt % of MWNTs showed slight changes in the CH bending vibrations, indicating the presence of intermolecular CH-pi interactions. The dissolution of various polymer composites containing low concentration of MWNTs in organic solvents was attributed to polymer coating on the MWNTs via noncovalent and nonspecific CH-pi interactions. The dissolution of MWNTs in organic solvents using common polymers used in this study indicates that the coating or wrapping is a general phenomenon occurring between polymers and carbon nanotubes.

1 aBaskaran, Durairaj1 aMays, Jimmy, W.1 aBratcher, Matthew, S. uhttps://library.ncl.res.in/content/noncovalent-and-nonspecific-molecular-interactions-polymers-multiwalled-carbon-nanotubes-101758nas a2200181 4500008004100000022001400041245011200055210006900167260007100236300001400307490000700321520103800328100002001366700001701386700002701403700002001430856012601450 2006 eng d a0024-929700aWell-defined poly(4-vinylbenzocyclobutene): synthesis by living anionic polymerization and characterization0 aWelldefined poly4vinylbenzocyclobutene synthesis by living anion a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY a3525-35300 v393 a

Living anionic polymerization of 4-vinylbenzocylobutene was performed in benzene at room temperature using sec-butyllithium as the initiator. Results of the kinetic studies indicated the termination- and transfer-free nature of the polymerization. Homopolymers with predictable molecular weights and narrow molecular weight distributions were produced, excluding the interference of the cyclobutene rings during initiation and propagation. Thermogravimetric analysis of poly( 4-vinylbenzocyclobutene) in air showed a small weight gain at similar to 200 degrees C, a rapid decomposition at similar to 455 degrees C, and a gradual decomposition at similar to 566 degrees C. This behavior was attributed to the formation of radicals from the pendent benzocyclobutene functionality through o-quinodimethane intermediates and simultaneous decomposition/ cross-linking reactions at high temperature. The living nature of the polymerization was also examined via sequential copolymerization with butadiene to form diblock copolymers.

1 aSakellariou, G.1 aBaskaran, D.1 aHadjichristidis, Nikos1 aMays, Jimmy, W. uhttps://library.ncl.res.in/content/well-defined-poly4-vinylbenzocyclobutene-synthesis-living-anionic-polymerization-and-000762nas a2200181 4500008004100000022001400041245012100055210006900176260007100245300001400316490000700330100002600337700001600363700002000379700002700399700002300426856013100449 2007 eng d a0897-475600aControlled covalent functionalization of multiwalled carbon nanotubes using [4+2] cycloaddition of benzocyclobutenes0 aControlled covalent functionalization of multiwalled carbon nano a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC a6370-63720 v191 aSakellariou, Georgios1 aJi, Haining1 aMays, Jimmy, W.1 aHadjichristidis, Nikos1 aBaskaran, Durairaj uhttps://library.ncl.res.in/content/controlled-covalent-functionalization-multiwalled-carbon-nanotubes-using-42-cycloaddition-001871nas a2200229 4500008004100000022001400041245008000055210006900135260009500204300001400299490000600313520101500319653002701334653003101361653001301392653003401405100002301439700002601462700002001488700002601508856010701534 2007 eng d a1533-488000aGrafting reactions of living macroanions with multi-walled carbon nanotubes0 aGrafting reactions of living macroanions with multiwalled carbon a25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USAbAMER SCIENTIFIC PUBLISHERScAPR a1560-15670 v73 a

Grafting reactions of living polystyryllithium (PSLi) with acid chloride containing multi-walled carbon nanotubes (MWNTs-COCl) were performed under vacuum in benzene at room temperature. Covalent grafting of polystyrene (PS) was characterized using spectroscopic, microscopic, and thermogravimetric analyses. Grafting at different ratios of macroanion to acylchloride of the carbon nanotubes showed that the grafting efficiency was not dependent on the concentration of the macroanions. The mole percent of PS present in the MWNTs-g-PS samples was inversely proportional to the precursor molecular weight of PSLi. Direct reactions of PSLi, polybutadienyllithium and n-butyllithium with pristine MWNTs without any functional groups were also performed in the presence and in the absence of tetrahydrofuran in benzene. The grafting reactions of living macroanions either with MWNTs-COCl or with pristine MWNTs indicated a partial grafting of polymer on the carbon nanotubes in benzene at room temperature.

10aAnionic polymerization10acovalent functionalization10agrafting10amulti-walled carbon nanotubes1 aBaskaran, Durairaj1 aSakellariou, Georgios1 aMays, Jimmy, W.1 aBratcher, Matthew, S. uhttps://library.ncl.res.in/content/grafting-reactions-living-macroanions-multi-walled-carbon-nanotubes