Ce travail porte sur l'étude du polyglyoxylate d'ethyle (PGEt) : sa synthèse, sa caractérisation et sa dégradation. Le PGEt a été obtenu par polymérisation anionique. Les conditions optimales font intervenir un amorçage par NE3 dans le CH2Cl2 à une température inférieure à -20°C. L'existence d'une température plafond (Tp = 310K pour [M]0 = 1M) nécessite l'utilisation d'agents de terminaison (phényl isocyanate ou bromure de 2-bromo-2-méthyl propionyle) afin d'obtenir des PGEt stables. La dégradation par hydrolyse in vitro du PGEt a été étudiée par RMN 1H, CES... Le mécanisme fait intervenir des coupures de chaines et des hydrolyses des esters. Les produits ultimes de dégradation identifiés sont l'éthanol et l'hydrate d'acide glyoxylique. Le caractère biodégradable du PGEt a été confirmé par respirométrie. Des études préliminaires de toxicité (sur des hématies, le nématode C. Elegans, et la croissance des plantes) n'ont pas révélé d'effet nocif du PGEt et de ses produits de dégradation. / This work focuses on the study of poly(ethyl glyoxylate) (PRtG), from its synthesis and its characterization to its degradation to some biological applications. The chosen conditions for PEtG's synthesis were initiated by an anionic way (NEt3) in presence of CH2Cl2. Because the ceiling temperature of the monomer (EtG) is low (7°C), it is necessary to block the hydroxyl ended groups generated in situ. The use of PhNCO leads to stables PEtG. The PEtG can be used as a macroinitiator of atom transfer radical polymerization (ATRP if it is wisely done. The copolymerization of styrene is then controlled. The degradation by in vitro hydrolysis of PEtG mainly led to ethanol and glyoxylic acid hydrate release. The biodegradable character of PGEt was assessed by a respirometric test and a preliminary study of toxicity (on red blood cells, worms and plants) revealed no significant effect at the concentrations generally used.

Résumé confidentiel / Résumé confidentiel

Möjligheten att syntetisera UV-härdande bindemedel från enbart förnyelsebara startmaterial (syra A och alkohol A) eller från kombinationer av dessa med konventionella monomerer (syra B, C och D; alkohol B, C, D, E samt cyklisk ester A) utvärderades. Effekten av två katalysatorer, tenn(II)oktanoat och butyltenn, på direkt förestring och på ringöppning utvärderades. Totalt framställdes 22 polyestrar som analyserades med avseende på syratal, medelmolekylvikt (SEC), kulörindex (Gardner), och strukturell sammansättning (NMR). Bindemedlen formulerades med UV-initiator och härdades med UV-ljus. De torra filmerna utvärderades med avseende på hårdhet (pendelhårdhet), flexibilitet och kemisk resistens.   Det var möjligt att framställa polyestrar baserade på ovan nämnda monomerer. Några monomer gav bäst egenskaper med avseende på pendelhårdhet och flexibilitet medan andra byggstenar resulterade i bättre kemisk resistens.

<p> A computer model is developed to simulate the emulsion copolymerization of styrene/butadiene in perfectly stirred batch, semi-batch or continuous flow reactors. The model considers free radical initiation by a redox mechanism, micellar particle nucleation, radical concentration as -a function of particle size, radical entry rate and termination rate and diffusion controlled termination and propagation reactions. It predicts conversion, copolymer composition, particle number, number and mass average molecular masses and tri- and tetra-functional branch frequencies. A simple method of estimating the particle size distribution is included in the model. Heat balances over the reactor and cooling jacket are considered and proportional-integra control of the reactor temperature is simulated.</p> <p> The model is used to simulate SBR copolymerization and styrene homopolymerization experimental data from the literature. These simulations tested only certain parts of the model and it is concluded that a more complete verification of the model can only be achieved by running a series of designed experiments. Qualitatively, the molecular mass, particle size distribution and reactor temperature predictions appear to be reasonable. The lack of appropriate temperature dependent rate constants currently limits the molecular mass predictions to isothermal conditions.</p> <p> A comparison of semi-batch operating policies designed to control copolymer composition is presented to illustrate the potential application of the model.</p> / Thesis / Master of Engineering (ME)

The use of waste gas such as carbon dioxide (CO2) to prepare useful and valuable polymers benefits both the economy and the environment. Various strategies have been developed to reduce CO2 emission as well as to transfer CO2 into high-value products. CO2/epoxide copolymerization is one of the most promising methods of not only reducing the CO2 emission from the atmosphere but also producing biodegradable CO2-based materials that are CO2 as source-abundant, renewable, cheap, non-flammable and non-toxic. However, the activation of CO2 is one of several problems associated with the polymerization of CO2 due to its stability as a thermodynamic end product. Herein, my dissertation describes the effectiveness of new lithium/phosphazene complexes to generate highly active species for CO2/epoxide copolymerization and to capture/activate CO2 molecules for the nucleophilic attack of the active species. Well-defined polycarbonates and polycarbonate-based block copolymers are produced that have control of molecular weights, unimodal distributions and narrow molecular weight distributions (Chapter 3 and 4). Besides, these complexes provide access to prepare CO2-based triblock copolymers that are powerful candidates to serve as the next generation of thermoplastic elastomers (Chapter 4). Additionally, these complexes are applied for the anionic polymerization of petrochemical-based sources such as styrene and dienes producing polymers in faster rate of polymerization with control of molecular characteristics (Chapter 2). A general introduction of polymers and their classification based on composition, chemical structure, mechanical properties, degradability, source, applications, and preparative methods, is covered in Chapter 1

Stilbene containing polymers are a group of interesting and versatile polymers. The pendent phenyl ring along the polymer backbone can impart unusual rigidity to the polymer backbone due to steric repulsion. By functionalizing stilbene, a variety of functional groups and ionic groups can be precisely placed along the polymer chain with tunable charge density. Therefore, stilbene containing polymers are potentially rod-like polyelectrolytes with controllable charges and charge density. They are the basis of a novel group of rigid synthetic polyelectrolytes and can be used for furthering our knowledge of rigid polyelectrolytes. A novel series of methyl substituted stilbenes were synthesized and copolymerized with maleic anhydride. A conversion-time study was undertaken to understand the methyl substituent effect on copolymerization rates. Methyl substituted stilbene-maleic anhydride copolymer compositions were determined by quantitative ¹³C 1D NMR. SEC measurements showed the weight average molecular weights of these copolymers vary from 3 000 to over 1 000 000 g/mol. No glass transition temperature or crystalline melting temperature was observed between 0 °C and 250 °C by DSC. TGA showed that these polymers have 5% weight loss around 290 °C. Precursors to a polycation and a polyanion based on functionalized stilbenes and maleimides have been prepared: poly(di-t-butyl-(E)-4,4′-stilbenedicarboxylate-co- N-(4-(t-butoxycarbonyl)phenyl)maleimide) and poly(N,N,Nâ ,Nâ -tetraalkyl-4,4′-di- aminostilbenes-co-N-4-(N′,N′-dimethylaminophenyl)-maleimide). These copolymer precursors were characterized by ¹H NMR, SEC, TGA, and DSC. The ¹H NMR spectrum indicated the rigidity of copolymer backbones. SEC measurements showed the weight average molecular weights of these copolymers vary from 5 000 to 11 700 g/mol. No glass transition temperature or crystalline melting temperature was observed between 0 °C and 175 °C by DSC for poly(di-t-butyl-(E)-4,4′-stilbenedicarboxylate-co-N-(4-(t-butoxy- carbonyl)phenyl)maleimide). TGA showed that this polymer has 5% weight loss around 210 °C and 26% weight loss on the first stage of decomposition which corresponds to elimination of t-butyl functional group in the copolymer. The homopolymerization of EMS-III via free radical polymerization, anionic polymerization and cationic polymerization was attempted. However, no polymer was obtained from any of these polymerization methods. In anionic polymerization, the solution changed to red upon the addition of the initiator sec-bu-Li, indicating the successful addition of the sec-bu-Li to EMS-III. However, the initiated monomer did not propagate to form homopolymer. / Master of Science

The research in this dissertation is focused on the synthesis and characterization of sterically crowded, precisely charged polyelectrolytes based on substituted stilbene comonomers. New sterically crowded polyelectrolytes based on functionalized stilbenes with maleic anhydride or functionalized N-phenylmaleimides were prepared via a "protected" precursor polymer strategy. The polyelectrolyte precursors readily dissolved in organic solvents and were characterized by 1H NMR, SEC, TGA, and DSC. The polyelectrolytes were obtained via simple deprotection chemistries. The use of different combinations of the donor-acceptor comonomer pairs and the alternating copolymerization of these comonomers lead to precise control over charge density and placement of charged groups along the polymer backbone. Analogous styrenic copolymers, for direct comparison to the stilbene structures, were also prepared. Broad peaks in 1H NMR spectra were observed. There were no thermal transitions measured by DSC below the degradation temperature. A strong polyelectrolyte effect, for both stilbene and styrene copolymers, occurred in deionized water and was suppressed by adding NaCl to the polymer solution. These results are not consistent with "rigid" rod polyelectrolytes in which chain collapse in the presence of added salt and chain expansion on dilution should not be observed. In response to these observations persistence length measurements were conducted on the stilbene and styrene copolymers to assess directly the steric crowding effect of added phenyl groups in stilbene copolymers. Both SEC and SAXS measurements were used to obtain persistence lengths. The results from three different approaches, Bohdanecký, graphical and Sharp and Bloomfield Global, were in good agreement. The persistence lengths of stilbene containing copolymers range from 3 to 6 nm and the added phenyl groups increase the rigidity of the polymer chain by about 30-50%. This puts these polymers into a broadly defined "semi-rigid" category of polymers and is consistent with the solution polyelectrolyte effect observed. In dilute solution characterization of stilbene containing polyanions, a 2-step dissociation behavior was observed for the two adjacent carboxylic acids in maleic acid containing polyanions. Stilbene polyanion solutions showed high Rh values in deionized water as shown by DLS measurements and a decrease of Rh values followed by aggregation upon gradual addition of salt. Bimodal peaks were observed in SEC measurements with the copolymer of 4-methylstilbene and maleic anhydride. DLS measurements indicated interchain aggregation as the origin of the apparent high molecular weight fraction. The antiviral activity of the polyanion based on sodium 4-styrenesulfonate and N-(4-sodium sulfophenyl)maleimide was found to be ~50 times higher than the microbicide, sodium poly(styrene sulfonate). The early study of antiviral activities of carboxylated stilbene and styrene polyanions also showed promising results. The synthesis of methyl sulfonate ester-functionalized polyanion precursors was attempted because they can be characterized without the complications caused by directly using charged sulfonate groups. / Ph. D.

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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.