Foram realizados experimentos de homopolimerização de estireno e copolimerização de estireno-divinilbenzeno em solução e suspensão aquosa pelos métodos convencional (FRP) e mediado por nitróxido (NMRP). Objetivou-se atingir um maior grau de entendimento sobre estes sistemas em relação ao que se tem na literatura. Para isto, três modelos matemáticos foram avaliados através de validação com os dados obtidos nos experimentos. Os experimentos foram conduzidos em reator de batelada isotérmico. As principais variáveis exploradas neste trabalho foram: temperatura de reação, concentração inicial de divinilbenzeno, diluição inicial da mistura de monômeros e técnicas de polimerização (FRP e NMRP). Os modelos matemáticos foram intitulados: Modelo A, Modelo B e Modelo C. O Modelo A consiste de um balanço de espécies não poliméricas e grupos poliméricos. A determinação das massas moleculares médias e da fração de gel foi feita através de balanços populacionais em termos de função geradora em conjunto com o método das características. Os modelos B e C consistiram de balanços de massa para espécies não poliméricas e método dos momentos para radicais ativos, radicais dormentes e polímero morto. A obtenção das massas moleculares médias e da fração de gel foi feita através do método do fracionamento numérico. Nestes dois modelos, foram consideradas as reações de ciclização através do método dos caminhos. Este método consiste num balanço de segmentos de cadeia que conectam grupos poliméricos. O número máximo de unidades monoméricas, considerado para estes segmentos foi 100 e o valor da constante cinética de ciclização do menor segmento ciclizável (3 unidades monoméricas) foi 450 s-1 para a temperatura de 90°C. O Modelo C leva em conta a redução da reatividade das ligações cruzadas em função do tamanho médio das cadeias em cada geração. Os resultados mostraram que, quando comparado com a FRP, a polimerização NMRP permite somente um controle limitado sobre o processo de reticulação, produzindo distribuições largas de tamanhos de cadeia. Micro e nanoestruturas foram identificadas em produtos obtidos por FRP e NMRP lineares e não lineares. Estas estruturas parecem ser consequência do processo de síntese (ex.: operação em temperatura de reação acima da temperatura de transição vítrea) e do tratamento dos produtos. Massa molecular média mássica e fração de gel foram afetadas consideravelmente pelas reações de ciclização em copolimerizações FRP, porém apresentaram pouca sensibilidade a estas reações em copolimerizações NMRP. A inclusão do mecanismo de ciclização, por si só (no Modelo B), não foi suficiente para produzir bons ajustes modelo/experimentos em termos de massa molecular média mássica (Mw) e fração de gel (Wg). No entanto, o Modelo C é capaz de fornecer boas previsões de Mw e Wg simultaneamente para os experimentos realizados a 90°C. O presente estudo mostrou uma análise na qual os modelos podem se complementar e fornecer subsídios para o desenvolvimento de um modelo unificado. / Homopolymerizations of styrene and copolymerizations of styrene-divinylbenzene were carried out in solution and aqueous suspension through conventional (FRP) and nitroxide-mediated (NMRP) techniques. The aim of the work was to reach a higher level of understanding in comparison to what is found in literature. In order to reach this goal, three mathematical models were assessed through validation using experimental data. The experiments were conducted in isothermal batch reactor. The main variables explored in this work were: reaction temperature, divinylbenzene initial concentration, initial dilution of monomers and polymerization techniques (FRP and NMRP). The mathematical models were named: Model A, Model B and Model C. The Model A consists of a balance of non-polymeric species and polymer groups. The average molecular weights and gel fraction were calculated through population balances in terms of generation function together with the method of characteristics. The models B and C were built using mass balance for non-polymeric species and the method of moments for active radicals, dormant radicals and dead polymer. The average molecular weights and gel fraction were calculated through the numerical fractionation technique. In these two models, cyclization reactions were considered through the method of paths. This method consists of a balance of chain segments which connect polymer groups. The maximum number of monomeric units considered for these segments was 100 and the value of the kinetic constant of cyclization for the smaller cyclizable path (3 monomeric units) was 450 s-1 at 90°C. The Model C takes into account the reduction of reactivity of the crosslink reactions in function of the average size of the chains in each generation. The results showed that, when compared with FRP, NMRP allows only a limited control over the crosslinking process, producing broad chain length distributions. Micro and nanostructures were identified in products obtained by linear and non-linear FRP and NMRP. These structures seem to be consequence of the synthesis process (e.g.: operation in reaction temperatures above the glass transition temperature) and of the products treatment. Weight average molecular weight and gel fraction were affected considerably by the cyclization reactions in FRP, however they presented few sensibility to these reactions in NMRP. The inclusion of the mechanism of cyclization, itself (in Model B), was not enough to obtain good model/experiments fittings in terms of weight average molecular weight (Mw) and weight fraction of gel (Wg). Although, the Model C is capable of providing good predictions of Mw and Wg simultaneously for the experiments carried out at 90°C. The present study showed an analysis in which the models can complement each other, providing subsidies for the development of a unified model.

Le but de cette thèse est d'évaluer le rôle de la solvatation des PCP (copolymère greffé utilisé en tant qu'additif du béton) sur la fluidité et la viscosité des bétons. Pour répondre à cette problématique, des copolymères greffés différant par la nature chimique des chaînes latérales sont synthétisés. L'état de solvatation des PCP est évalué à l'aide du paramètre de Flory-Huggins χ. Ce dernier est calculé à partir du 2nd coefficient du viriel A2, déterminé par diffusion de la lumière. Des valeurs du paramètre χ de 0,37 ; 0,43 ; 0,47 et 0,48 ont été obtenues pour des PCP comportant des chaînes latérales à base d'éthylène glycol (EG), de 2-méthyloxazoline (MOx), de N-vinylpyrrolidone (NVP) et de N-acryloylmorpholine (NAM), respectivement. Le pouvoir couvrant des PCP et leur épaisseur de couche peuvent être calculés par l'intermédiaire d'une formule proposée par Flatt. L'introduction des PCP à différents dosages (donc différents taux de recouvrement) à des suspensions de calcite a permis de montrer qu'à même taux de recouvrement de surface, tous les PCP induisaient la même fluidité, alors que l'épaisseur de couche de PCP diffère de plus de 50% dans les cas les plus extrêmes. Le taux de recouvrement de surface joue un rôle tout aussi important en ce qui concerne la viscosité des suspensions. Appliquer ces conclusions sur un mortier s'avère délicat car les PCP pourraient entrainer des retards d'hydratation différents en fonction de la nature des chaînes latérales / The objective of this PhD work is the evaluation of the role of the solvation of PCP (grafted copolymer used in concrete as additive) on the concrete fluidity and viscosity. Grafted copolymers with different side-chains were synthesized. The solvation state of the PCP was estimated by mean of the χ Flory-Huggins parameter. The latter was calculated from the 2nd virial coefficient A2, itself determined by light scattering measurements. χ -parameter values of 0,37 ; 0,43 ; 0,47 and 0,48 are obtained for PCP respectively possessing ethylene glycol (EG), 2-methyloxazoline, N-vinylpyrrolidone and N-acryloylmorpholine-based side-chains. The surface coverage of the PCPs and their layer thickness can be calculated with Flatt’s formula. The introduction of the PCPs at different contents (therefore different surface coverage ratio) to calcite suspensions showed that at same surface coverage ratio, all PCPs induce the same fluidity, although the adsorbed PCP layer thickness differed up to 50% in the certain cases. The surface coverage played also a keyrole in the suspensions viscosity. The transposition of these results to a mortar seemed however risky since PCPs might lead to hydration delays depending on the chemical nature of the side-chains

Ces travaux de thèse ont permis de développer une méthodologie qui permet la désacidification et le renforcement simultanés du papier, en vue de l’application à des papiers de presse anciens. Les traitements novateurs proposés sont des réseaux à base de polysiloxanes à fonctionnalité alcaline, synthétisés à partir d’un mélange de monomères difonctionnel (AMDES ou DIAMINO) et trifonctionnel (APTES). Leur incorporation et les effets engendrés ont tout d’abord été démontrés sur un papier modèle pur cellulose de coton.La caractérisation d’une collection de papiers de presse de la Bibliothèque nationale de France (BnF) a permis d’obtenir des informations sur l’évolution de la composition de ces papiers entre 1950 et 2010 et d’étayer ainsi le choix de cinq autres papiers modèles de composition variée comme supports pour l’étude de l’application des traitements. L’évaluation de l’efficacité des traitements en fonction de la composition des papiers a été basée principalement sur les propriétés chimiques d’alcalinisation (mesures de réserve alcaline) et de résistance mécanique conférées (essais de résistance mécanique).La stabilité chimique des traitements face à deux types d’agression (exposition à l’acide formique et hygrothermique) a été étudiée. Une fois optimisés en proportions relative des monomères, ces traitements ont été appliqués à des papiers modèles pré-dégradés par des vieillissements artificiels permettant ainsi d’étudier l’efficacité des traitements en fonction de l’état de dégradation du papier. Le traitement identifié comme le plus efficace a ensuite été appliqué à un papier journal datant de 1922. / This dissertation describes the development of novel conservation treatments for simultaneous strengthening and deacidification of paper, for the purpose of the application to aged newsprint. The newly proposed treatments are based on the incorporation of polysiloxane networks with an alkaline functionality, synthesized from a mixture of bifunctional (AMDES or DIAMINO) and trifunctional (APTES) monomers. The application and the generated effects on a paper made of cotton linters were firstly demonstrated.The characterization of a collection of newsprint papers from the national French Library (BnF) dating from 1950 to 2010 yielded information about the evolution of the composition of the papers during this period. These results have comforted the choice of five more model papers as supports for the treatments. The efficiency of the treatments was appraised mainly based on the chemical properties of alkalization (alkaline reserve measurements) and conferred mechanical strength (mechanical testing).The chemical stability of the treatments when exposed to two types of aggressions (exposure to formic acid and hygrothermal ageing) was studied. Once the relative proportions of the monomers were optimized, the treatments were applied to model papers artificially pre-degraded in order to study the effectiveness of the treatments according to the state of degradation of the paper. The most effective treatment identified was then applied to a newsprint paper dating from 1922.

Acryloyloxybenzoic acid (ABA) was prepared by the condensation reaction of acryloyl chloride with p-hydroxybenzoic acid in alkaline medium. The polymerization and grafting of ABA onto Polypropylene were anticipated to occur simultaneously in melt mixing at high temperature. The monomer showed liquid crystalline property. For a better dispersion of ABA in PP before graft copolymerization, a masterbatch of 50-50 (by weight) low density polyethylene + ABA was prepared, which was then used for 5, 10, 15 % ABA + PP mixtures in the Brabender Plasti Corder. Furthermore, these compositions were reprocessed at the same temperature in the molten state. Compression molding was used to prepare films for characterization experiments at 200 &ordm / C under 15000 psi for approximately 3-5 minutes. The graft copolymers were characterized by several techniques / DSC, FTIR, MFI, SEM and mechanical testing. In DSC thermograms the crystallization of PP was seen at approximately 160&ordm / C. An endothermic peak was also assigned to grafted PABA at 280&ordm / C . The incorporation of ABA onto the PP backbone as a graft copolymer (PABA-g-PP) at low percentages results in a possible rearrangement, where tensile strength values increased, while strain decreased. The grafting goes through thermal radicalic mechanism. MFI values were found to increase from 8.7 to 16.35 g/10 min at 10 wt % ABA, then decreased to 10.57 g/10 min at 15 wt % ABA. It is most likely that the presence of PABA produced easy orientational flow up to 10 % of ABA, but at 15 % ABA addition caused a slight decrease in MFI. The tensile test specimens were analyzed by Scanning Electron Microscope. None of the three samples exhibited phase separation. This observation confirms that the graft copolymerization occurrs in a homogenous manner onto PP. The brittle nature of material is observed at all three compositions.

The Knorr-Paal reaction of 1,4-di(2-thienyl)-1,4-butanedione with aniline to yield 1-phenyl-2,5-di(2-thienyl)-1H-pyrrole (PTP) was performed in the presence of catalytical amounts of p-toluenesulfonic acid (PTSA). Chemical polymerization of the monomer yielded a soluble polymer. Structures of both the monomer and the polymer were investigated by Nuclear Magnetic Resonance (1H and 13C NMR) and Fourier Transform Infrared (FTIR) Spectroscopy. The average molecular weight of the chemically synthesized polymer was determined by Gel Permeation Chromatography (GPC) as Mn = 7.2 x 103 g/mol. The electrochemical oxidative polymerization of PTP was carried out via potentiodynamic electrolysis in the presence of LiClO4, NaClO4 (1:1) being the supporting electrolyte in acetonitrile. Electrochemical copolymerization of PTP with 3,4-ethylenedioxythiophene (EDOT) was carried out in acetonitrile (ACN)/ NaClO4/LiClO4 (0.1M) solvent-electrolyte couple system via potentiodynamic electrolysis. Cyclic voltammetry was used to investigate electrochemical behavior of the monomer and redox reactions of conducting polymers. Conductivities of films of the polymers were measured by four-probe technique. Surface morphologies of the films were investigated by Scanning Electron Microscope (SEM). Electrochromic properties of the conducting polymers were investigated via spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemical analysis of P(PTP) revealed electronic transitions at 413, 600 and 900 nm corresponding to &amp / #960 / -&amp / #960 / * transition, polaron, and bipolaron band formations, respectively. The spectroelectrochemical behavior of the P(PTP-co-EDOT) in comparison to those of the respective homopolymers revealed solid evidence of copolymerization based upon the differences in the spectral signatures. Switching time of the polymers was evaluated by kinetic studies upon measuring the percent transmittance (%T) at the maximum contrast point. As an application, absorption/transmission type electrochromic devices with ITO/homopolymer(copolymer)/gel electrolyte/PEDOT/ITO configuration was constructed, where homopolymer (copolymer) and PEDOT functioned as the anodically and the cathodically coloring layers, respectively. Spectroelectrochemistry, switching ability and open circuit memory of the devices were investigated. The results revealed that these devices have good switching times, reasonable contrasts and optical memories.

A novel electroactive monomer 5,8-Di(1H-pyrrol-2-yl)-2, 3-di(thiophen-2-yl) quinoxaline (PTQ) was successfully synthesized via Stille Coupling reaction between quinoxaline and pyrrole. Nuclear magnetic resonance (1H NMR and 13C NMR) and Mass spectroscopy were used to characterize the monomer. The monomer was electrochemically polymerized in the presence of tetrabutylammonium perchlorate (TBAP) as supporting electrolyte in dichloromethane. Monomer reveals relatively low oxidation potential at +0.70V. Spectroelectrochemical behaviors and switching ability of homopolymer were investigated by UV-Vis spectroscopy and cyclic voltammetry. Two &amp / #960 / -&amp / #960 / * transitions were observed at 400 nm and 815 nm with a low band gap, 1.0 eV. Polymer possesses 66% optical contrast in the Near IR region, which may be promising in NIR electrochromic device applications. Spectroelectrochemical behaviors and switching ability of copolymers were investigated by UV-Vis spectroscopy and cyclic voltammetry. Copolymers of PTQ in the presence of BiEDOT and BEBT were synthesized via potentiodynamic method in DCM/TBAP (0.1 M) solvent-electrolyte couple. P(PTQ-co-BiEDOT) reveals oxidation potential at +0.45V, whereas P(PTQ-co-BEBT) reveals oxidation potential at +0.70V. The spectroelectrochemical behavior of the P(PTQ-co-BiEDOT) and P(PTQ-co-BEBT) in comparison to homopolymer revealed solid evidence of copolymerization based upon the differences in the spectral signatures. Switching time of the polymers was evaluated by kinetic studies upon measuring the percent transmittance (%T) at the maximum contrast point.

GRAFT COPOLYMERIZATION OF p-ACRYLOYLOXYBENZOIC ACID AND p-METHACRYLOYLOXYBENZOIC ACID ONTO ISOTACTIC POLYPROPYLENE The monomers, p-acryloyloxybenzoic acid (ABA) and p-methacryloyloxybenzoic acid (MBA) were synthesized by condensation reaction of corresponding acid chlorides with p-hydroxybenzoic acid in alkaline medium. The polymerization of the monomers were studied by several techniques. Polyacryloyloxybenzoic acid (PABA) was obtained by &amp / #947 / -radiation induced, solution and bulk melt polymerization by initiation of dicumyl peroxide (DCP). Polymethacryloyloxybenzoic acid (PMBA) could be obtained by only bulk melt polymerization. The graft copolymerization of the monomers onto isotactic polypropylene, IPP, was successfully carried out only with bulk melt polymerization. The IPP used in the graft copolymerization was firstly subjected to &amp / #947 / -radiation to create active sites for grafting. The graft copolymerization of the monomers, ABA and MBA onto IPP were initiated by these active sites. The grafting was studied at constant concentration of the monomers in the reaction mixture (50%) and at different reaction temperatures (170, 185, 202, 215 and 225&deg / C). The maximum grafting of PABA and PMBA were found to be 33.1% and 33.9% in the graft copolymers, respectively. The maximum grafting was reached in shorter times at higher temperatures, and it also increased with the increase of concentration of the monomers in the reaction medium. The graft copolymerization was also carried out by using initiator, DCP at 170&deg / C, however, the grafting extent was lower due to the homopolymerization of the monomers and the direct reactions between peroxides of initiator and peroxides on IPP. The graft copolymers were characterized by several techniques, DSC, WAX, TG/IR, MS, SEM and mechanical testing. The formation of both crystalline forms of (&amp / #61537 / 1 and &amp / #61537 / 2) were observed in the products obtained at 170&deg / C. The graft copolymerization of ABA did not have any significance on the formation of both forms of &amp / #61537 / form, while MBA lead to increase in &amp / #61537 / 2 form. The &amp / #61538 / crystalline modification formed in PABA-g-PP products obtained at 185&deg / C and at higher temperature and also in the second run of DSC studies after fast cooling. &amp / #61538 / form was not observed in graft copolymers of PMBA The decomposition mechanism of PABA, PMBA and the graft coproducts were studied by mass spectrometry and TG/IR. The polymers degraded predominantly by decomposition of side groups giving phenol, benzoic acid, hydroxybenzoic acid, carbondioxide and cyclodiene mainly. The mechanical properties of the graft copolymers showed an improvement particularly in tensile strength and modulus. The maximum tensile strength and modulus of PABA-g-PP were found as 41.1 and 881 MPa, and the values of PMBA-g-PP were measured as 35.9 and 721 MPa, respectively. These values were 28.1 and 486 MPa for irradiated IPP and 33.9 and 632 MPa for virgin IPP, respectively. The copolymerization of ABA did not alter the impact properties of the graft copolymer, while a slight decrease was observed in PMBA-g-PP samples. The tensile and impact fractured surface of the graft copolymers studied by scanning electron microscopy showed homogeneous structure. The brittle nature with some extent of ductility was seen in the samples.

2,5-Di(thiophen-2-yl)-1-p-tolyl-1H-pyrrole (DTTP) was synthesized via reaction of 1,4-di(2-thienyl)-1,4-butanedione with p-toluidine in the presence of catalytical amount of p-toluenesulfonic acid (PTSA). Homopolymer P(DTTP) was achieved both by chemical and electrochemical techniques. Chemical polymerization of the monomer yielded a soluble polymer. The average molecular weight was determined by gel permeation chromatography (GPC) as Mn: 2.5x103 g/mol. The monomer was electrochemically polymerized in the presence of LiClO4, NaClO4 (1:1) as the supporting electrolyte in acetonitrile. Copolymer of DTTP in the presence of EDOT was synthesized via potentiodynamic method in ACN/ NaClO4/LiClO4 (0.1 M) solvent-electrolyte couple. Structural characterizations of samples were carried out via 1H, 13C Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Electrochemical behaviors of monomer and polymers were determined by Cyclic Voltammetry (CV). The morphologies of the polymer films were examined by Scanning Electron Microscopy (SEM). Conductivities of the films were measured by four probe technique. Electrochromic and spectroelectrochemical behavior of the polymers coated on ITO glass electrode were investigated, and their ability of employment in device construction was examined. Spectroelectrochemistry analysis of P(DTTP) revealed an electronic transition at 428 nm corresponding to &amp / #1087 / &amp / #8211 / &amp / #1087 / * transition with a band gap of 2.1 eV whereas P(DTTP-co-EDOT) revealed an electronic transition at 448 nm corresponding to &amp / #1087 / - &amp / #1087 / * transition with a band gap of 1.8 eV. Electrochromic investigations showed that P(DTTP) switches between greenish yellow and blue while P(DTTP-co-EDOT) was found to be multichromic, switching between red, yellow and blue. Switching time of the polymers was evaluated by a kinetic study upon measuring the percent transmittance (%T) at the maximum contrast point. Dual type polymer electrochromic devices (ECDs) based on P(DTTP) and P(DTTP-co-EDOT) with poly(3,4-ethylenedioxythiophene) (PEDOT) were constructed. Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts and optical memories.

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