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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Synthèse de nanogels à base de poly(liquides ioniques), par copolymérisation radicalaire réticulante contrôlée par le cobalt, pour des applications de revêtement / Synthesis of poly(ionic liquid)-type nanogels by cobalt-mediated radical cross-linking copolymerization, for coating applications

Weiss-Maurin, Mathilde 20 September 2016 (has links)
La synthèse de nanogels par voie directe est étudiée par la copolymérisationradicalaire réticulante contrôlée par le cobalt (CMRCcP) d’un monomère monovinylique et d’unréticulant divinylique. La synthèse de nanogels globulaires a été réalisée en utilisant unsystème de co-monomères soit neutres (acétate de vinyle et adiapte de divinyle) soit liquidesioniques. Le contrôle de la polymérisation est vérifié dans tous les cas, les liaisons C-Cosituées aux extrémités des chaînes polymères ont été réactivées, afin de former des nanogelsde « seconde-génération ». Dans le cas de monomères liquides ioniques, différents contreanionsont été utilisés afin de jouer sur l’hydrophilie des co-monomères : la CMRCcP dubromure de N-vinyl-3-ethyl imidazolium (VEtImBr) et du bromure de 1,13-divinyl-3-decyldiimidazolium (DVImBr) a été réalisée dans l’eau, à 30 °C, pour former des nanogelspoly(VEtImbr-co-DVImBr) hydrophiles. Les propriétés antibactériennes de ces nanogels ontété étudiées.Les pendants hydrophobes de ces nanogels à base de PILs ont été synthétisés via laCMRCcP directe, dans l’acétate d’éthyle, de co-monomères contenant des contre-anionsbis(trifluromethanesulfonyl)imide (NTf2-). La capacité à former des surfaces poreusesordonnées de ces nanogels hydrophobes poly(VEtImNTf2-co-DVImNTf2) a été examinée, ainsique leur conductivité ioniques en films minces.Des copolymérisations ‘mixtes’ ont également été étudiées, dans l’optique de formerdifférentes architectures nanogels en utilisant des co-monomères ayant des réactivités trèsdifférentes. / The syntheses of globular nanogels were first investigated under mild conditions,using a mono- and a divinyl co-monomer with similar reactivities. CMRCcP was implementedon either neutral (vinyl acetate (VAc) and divinyl adipate (DVA)) co-monomers, or ionic liquidco-monomers. Control over each polymerization was ascertained, and dormant cobaltcarbonchain-ends could be re-activated to form “second-generation” nanogels. CMRCcP ofN-vinyl-3-ethyl imidazolium bromide (VEtImBr) and 1,13-divinyl-3-decyl diimidazoliumbromide (DVImBr) was achieved in water at 30 °C, leading to hydrophilic poly(VEtImBr-co-DVImBr) nanogels. The antibacterial activity of these cross-linked structures wasinvestigated. The hydrophobic pendants of these PIL-based nanogels were synthesized viadirect CMRCcP in ethyl acetate, using bis(trifluromethanesulfonyl)imide (NTf2-) counteranions. An array of these poly(VEtImNTf2-co-DVImNTf2) nanogels was then investigated aspossible coatings for porous patterned surfaces, and their ionic conductivity assessed.Different cross-linked architecture were approached, using a mono- and a divinyl comonomersof completely different reactivities.
2

Síntese de ligantes diimínicos para obtenção de complexos organocobalto(III) para polimerização radicalar mediada por cobalto / Synthesis of diimine ligands to obtain organocobalt(III) complexes for cobalt-mediated radical polymerization

Rocha, Beatriz Aline Riga [UNESP] 22 February 2017 (has links)
Submitted by Beatriz Aline Riga null (beatriz_aline16@hotmail.com) on 2017-03-15T18:07:31Z No. of bitstreams: 1 Riga Rocha, B. A._me_sjrp.pdf: 4397938 bytes, checksum: 97cd69af09e5df0e1dcc372a541946c2 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-03-21T16:17:50Z (GMT) No. of bitstreams: 1 rocha_bar_me_sjrp.pdf: 4397938 bytes, checksum: 97cd69af09e5df0e1dcc372a541946c2 (MD5) / Made available in DSpace on 2017-03-21T16:17:50Z (GMT). No. of bitstreams: 1 rocha_bar_me_sjrp.pdf: 4397938 bytes, checksum: 97cd69af09e5df0e1dcc372a541946c2 (MD5) Previous issue date: 2017-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho objetivou-se a síntese e caracterização de oito complexos de cobalto(II) que fossem aptos a atuarem como agentes controladores na Polimerização Radicalar Mediada por Cobalto do monômero acetato de vinila. Através da modulação da esfera de coordenação destes complexos com a alteração dos efeitos estéricos e eletrônicos promovidos pela coordenação de ligantes α-diiminas, buscou-se estabelecer parâmetros para propor a forma como estes complexos mediam a CMRP do referido monômero. Os complexos foram divididos em dois grupos, objetivando uma avaliação mais eficiente da forma como os efeitos estéricos e eletrônicos interferem na capacidade controladora dos mesmos. Após a variação sistemática das proporções molares entre complexo, iniciador e monômero encontrou-se na proporção [Co]/[AIBN]/[VAc] = 1/3,25/542 os resultados mais satisfatórios deste trabalho. O uso de DMSO fora prejudicial para os complexos 2a-c, porém fez com que os complexos 2d-h apresentassem melhorias, reduzindo seus valores de polidispersidade e aumentando as massas moleculares dos polímeros. O complexo 2b fora escolhido como o melhor controlador do grupo do efeito estérico, por reunir em si as características estérias e eletrônicas que o fizeram apresentar os menores valores de polidispersidade (Đmáx = 1,43). Com relação ao grupo de complexos do efeito eletrônico, fora o complexo 2f que, devido à maior estabilidade estrutural conferida ao complexo por seu substituinte cicloexil, apresentara as menores polidispersidades de seu grupo, entre 1,12 e 1,58. / This work aimed the synthesis and characterization of eight cobalt(II) complexes which could be able to act as controlling agents in vinyl acetate radical polymerization mediated by cobalt. By modulating the coordination sphere of these complexes, modifying the steric and electronic effects offered by the α-diimine ligands, we sought to establish parameters to propose how these complexes mediate the CMRP of vinyl acetate. The complexes were split in two groups in way to assess efficiently how the electronic and steric effects can affect the controlling capacity of the CoII(α-diimine).A systematic variation of the molar ratio such as [Co]/[initiator] and [Co]/[monomer] made it possible to choose [Co]/[initiator]/[monomer] = 1/3.25/542 as the ratio that provided certain level of control. The addition of DMSO was detrimental to the complexes 2a-c, but caused an improvement to the activity of complexes 2dh, reducing their polydispersity values and increasing the molecular weights of the polymers. Complex 2b was chosen as the best controller of the steric effect group, its steric and electronic characteristics made possible to reach the lowest polydispersity of its group (Đmax = 1.43).Regarding to the group of complexes of the electronic effect, it was the complex 2f that had the smallest polydispersity of its group, between 1.12 and 1.58, due to the greater structural stability conferred to the complex by its cyclohexyl substituent.
3

Polymérisation radicalaire contrôlée : le défi de l'éthylène / Controlled radical polymerization : the challenge of ethylene

Dommanget, Cédric 12 November 2013 (has links)
Les travaux présentés dans cette thèse portent sur le contrôle de la polymérisation radicalaire de l'éthylène à basse pression (200 bar) et basse température (70 °C) et sur la synthèse de copolymères à blocs contenant au moins un segment de polyéthylène. Quatre techniques de polymérisation, couramment utilisées en ingénierie macromoléculaire, ont été étudiées : NMP, CMRP, RAFT/MADIX et ESCP. Nos études sur le nitroxyde SG1 (NMP) et le bis(acétylacétonate) de cobalt (CMRP) ont montré que ces composés sont inefficaces pour contrôler la polymérisation de l'éthylène. Un comportement inattendu du bis(acétylacétonate) de cobalt a cependant été mis en évidence. Il semblerait que ces complexes de cobalt favorisent les réactions de couplage entre les radicaux propagateurs. En revanche, la première polymérisation radicalaire contrôlée de l'éthylène a été atteinte grâce à l'utilisation de xanthates (RAFT/MADIX). Les polyéthylènes synthétisés possèdent des masses molaires qui augmentent linéairement avec la conversion et des dispersités faibles. Le caractère pseudo-vivant de la réaction a été démontré par la synthèse de copolymères à blocs poly(acétate de vinyle)-b-polyéthylène. L'utilisation de nitrones (ESCP) a également permis l'introduction d'une fonction réactive au centre des chaînes de polyéthylène et la synthèse de copolymères triblocs de type ABA, où les blocs latéraux A sont en polystyrène ou polyacrylate et le bloc central B est en Polyéthylène / The work presented in this thesis displays the controlled radical polymerization of ethylene at low temperature (70 °C) and low pressure (200 bar) and the synthesis of block copolymers featuring polyethylene segments. Four polymerization techniques, commonly used in macromolecular engineering, were studied: NMP, CMRP, RAFT/MADIX and ESCP. Our investigation of the use of SG1 nitroxide (NMP) and cobalt (II) acetylacetonate (CMRP) as controlling agents demonstrated their inability to control the polymerization of ethylene. Nonetheless, an unexpected reaction with cobalt (II) acetylacetonate was observed. The coupling reaction between propagating radicals appeared to be favored by the presence of this compound. On the other hand, the first controlled polymerization of ethylene was successfully achieved by using xanthate (RAFT/MADIX). A linear increase of molecular weight with conversion and low polydispersities were observed for the produced polyethylenes. The reaction was demonstrated to be a pseudo-living polymerization by the synthesis of block copolymers poly(vinyl acetate)-b-polyethylene. In addition, midchain-functionalized polyethylenes and ABA type block copolymers, with polystyrene or polyacrylate as the A block and polyethylene as the B block, were also prepared using nitrone based polymerization technique (ESCP)
4

Síntese e aplicação de complexos de cobalto(II) coordenados a ligantes tetraimínicos na polimerização radicalar de acetato de vinila mediada por organometálicos / Synthesis and application of cobalt(II) complexes coordinated tetraimínes ligands in radical polymerization vinyl acetate mediated by organometallic

Sás, Juliana Frizarin Campos [UNESP] 31 March 2017 (has links)
Submitted by JULIANA FRIZARIN SAS RODRIGUES DOS SANTOS null (julianafrizarin@yahoo.com.br) on 2017-04-27T02:18:35Z No. of bitstreams: 1 Juliana Frizarin Campos Sás33.pdf: 1373618 bytes, checksum: b57a53096f87b32c52b1f3772bfc5e3d (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-03T13:59:38Z (GMT) No. of bitstreams: 1 sas_jfc_me_sjrp.pdf: 1373618 bytes, checksum: b57a53096f87b32c52b1f3772bfc5e3d (MD5) / Made available in DSpace on 2017-05-03T13:59:38Z (GMT). No. of bitstreams: 1 sas_jfc_me_sjrp.pdf: 1373618 bytes, checksum: b57a53096f87b32c52b1f3772bfc5e3d (MD5) Previous issue date: 2017-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O trabalho reporta a síntese de dois novos complexos de cobalto(II), coordenados a ligantes tetraimínicos, estes foram denominados [Co(beb)](PF6)2 e [Co(bfb)](PF6)2. Os complexos foram caracterizados por Espectroscopia de Infravermelho (FT-IR), Espectroscopia de Ultravioleta-visível (UV-Vis) e Voltametria Cíclica (VC). A polimerização radicalar de acetato de vinila (VAc) foi iniciada pelo azobisisobutironitrila (AIBN) e realizada na presença de [Co(beb)](PF6)2 ou [Co(bfb)](PF6)2 como agentes controladores, a temperatura de 65 ºC. As massas moleculares de poliacetato de vinila (PVAc) foram analisadas por GPC e Cg. / This study describes the synthesis of two novel cobalt(II) complexes, coordinated to tetraimine ligands [Co(beb)](PF6)2 and [Co(bfb)](PF6)2, where beb = 1,2-diphenylethane-bis(N2 -benzylidene-N1 -methyleneethane- 1,2-diamine) and bfb = 1,2-diphenylethane-bis(N2 -benzylide-N1 - methylenebenzene-1,2-diamine). The complexes were characterized by FT-IR, UV-Vis and Cyclic Voltammetry. The radical polymerization of vinyl acetate (VAc) initiated by azobisisobutyronitrile (AIBN) was carried out under different reaction conditions in the presence of [Co(beb)](PF6)2 or [Co(bfb)](PF6)2 as mediators. The systematic variation of the reaction conditions, such as [initiator]/[Co] and [monomer]/[Co] molar ratios, affected the polymerization rates and the molecular weights, reaching a certain level of control. The [Co(beb)](PF6)2 complex was shown to be more efficient in controlling the polymerization of VAc when compared to the [Co(bfb)](PF6)2 complex.

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