1. Improved methods for carrying out the reaction between sodium and acetic anhydride have been presented. Separation of reaction products and quantitative determination have been made easier by means of the improvements. 2. The only products isolated from either room-temperature or high-temperature runs have been sodium acetate and a resinous material believed to be a polymer of diacetyl. No diacetyl has been isolated from the original products of any reaction. 3. Comparison has been made between reactions at room temperature and runs made at high temperatures. Room temperature reactions have been found to give the same products as high-temperature runs but in much smaller amounts. 4. Theoretical discussion of the reaction is presented. A possible mechanism for formation of the resin are proposed. 5. Suggestions for future study of the problem are given. / M.S.

Treatment of dichloromaleic anhydride and 1,8-diaminonaphthalene in either benzene or toluene under refluxing conditions gives low yields of the new heterocyclic compound 8,9-dichloropyrrolo[1,2-a]perimidin-10-one. This product has been isolated and characterized in solution by NMR, IR, and UV/vis spectroscopies, and the solid-state structure of 8,9-dichloropyrrolo[1,2-a]perimidin-10-one has been established by X-ray crystallography. The nature of the HOMO and LUMO levels of 8,9-dichloropyrrolo[1,2-a]perimidin-10-one has been studied by extended Hückel molecular orbital calculations.

Th. doct.-ing.--Toulouse 3, 1977. N°: 564.

La thèse porte sur l’étude de la morphologie et des différentes propriétés thermiques, mécaniques et barrières à la vapeur d’eau des nanobiocomposites à base de poly acide lactique (pla). La première partie est consacrée au greffage de l’anhydride maléique (am) sur le poly acide lactique plagma et à la mise en oeuvre de nanobiocomposites pla/cloisites, plagma/cloisites et pla/plagma/cloisites en utilisant deux cloisites® différentes (c20a et c30b), préparés par voie fondue. Au travers des différentes techniques utilisées, les résultats révèlent que les nanobiocomposites pla/cloisites élaborés se caractérisent par une morphologie mixte intercalée-exfoliée. L’ensemble des échantillons élaborés indiquent une meilleure dispersion de la cloisite apolaire c20a en présence de l’anhydride maléique et la réagrégation de la cloisite polaire c30b et par conséquent, l’amélioration à la fois des propriétés mécaniques et barrières à la vapeur d’eau des nanobiocomposites à base de la c20a. La seconde partie traite l’influence des groupements fonctionnels d’oxyde de graphène synthetisé au laboratoire et de graphène fonctionnalisé époxy commercialisé et fournit par nanovia (france) sur la dispersion des nanofeuillets de graphène au sein de la matrice pla, en présence ou en absence du compatibilisant plagma. L’étude révèle que la présence du compatibilisant améliore la dispersion de deux nanocharges étudiées. Le maximum des performances rhéologiques indiquant la meilleure dispersion de la nanocharge est enregistré pour une faible quantité d’oxyde de graphène possédant plus de groupements fonctionnels contenant l’atome d’oxygène. Les propriétés thermiques et barrières ont été considérablement améliorées avec l’incorporation des deux nanocharges et en présence de l’agent compatibilisant plagma. L’étude montre aussi que les propriétés mécaniques en traction des nanobiocomposites à base de graphène fonctionnalisé époxy (gfe) ont été améliorées en présence du plagma. / The thesis focuses on the study of the morphology and thermal, mechanical and barrier properties of the nanobiocomposites based on poly lactic acid (pla). The first part is devoted to the grafting of maleic anhydride (ma) on the poly lactic acid plagma and the elaboration of the nanobiocomposites pla/cloisites, plagma/cloisites and pla/plagma/cloisitres using two different cloisites (c20a and c30b), prepared by melt intercalation and the characterization of the main properties. The results indicate that the pla/cloisites nanobiocomposites exhibit a mixed intercalated-exfoliated morphology. All the prepared samples showed an improvement in both thermal, mechanical and barrier properties in the presence of the nanofiller. All prepared samples show better dispersion of apolar cloisite (c20a) in the presence of maleic anhydride and reaggregation of the polar cloisite (c30b) and therefore, the improvement of both the mechanical and barrier properties of the nanobiocomposites based on c20a. The second section discusses the effect of the functional groups of graphene oxide synthetized in the laboratory and the graphene fonctionnalized epoxy marketed and supplied by nanovia (france) on the dispersion of the graphene nanofillers in the pla matrix. The study reveals that the presence of compatibilizer improves the dispersion of two studied nanofillers. Maximum rheological performance indicating better dispersion of the nanofiller is registered for a small amount of graphene oxide (og) with more functional groups containing oxygen atom. The thermal and barriers properties have been considerably improved with the incorporation of two nanofillers and in the presence of plagma compatibilizer. The study also shows that the tensile properties of the pla containing graphene functionalized epoxy (gfe) were improved in the presence of plagma.

Diplomová práce se zabývá roubováním maleinanhydridu a anhydridu kyseliny itakonové na kyselinu poly(mléčnou) (PLA). U modifikované kyseliny poly(mléčné) byla sledována závislost konverze monomerů na různých molárních poměrech monomer/iniciátor při teplotách 180°C a 200°C. Množství naroubovaného monomeru bylo stanovováno acidobazickou titrací a pomocí FT-IR spektroskopií. Vliv stupně naroubování na krystalinitu modifikované PLA byl zjišťován pomocí diferenční kompenzační kalorimetrie, DSC. Degradace PLA byla orientačně pozorována pomocí indexu toku taveniny, MFI.

The theoretical part describes the principles of the free-radical induced grafting and the influence of various parameters on the reactions course. The literature research summarizes the latest knowledge in the field of the reactive modification of polypropylene (PP), it is mainly focused on the PP modification using an unsaturated acid anhydrides. Theoretical part describes the various procedures and modification of technology in order to increase the grafting yield of maleation. The experimental part is determined by the influence of the stabilizers concentration, the peroxide structure, and the binary mixture of monomers on the grafting yield and the reaction course. In the first part, the critical stabilizers concentration was determined based on the experimentally obtained relationship between the grafting yield and the stabilizers concentration. A kinetic schema of grafting of MAH onto PP in the presence of stabilizers has been proposed and compared with the experimental results. The effect of the stabilizers on the extent of the undesirable b-scission was evaluated based on the melt flow rate (MFR) and the rheological curves of PP-g-MAH. In the second part, the effect of the peroxide structure and the concentration of reactants on the grafting yield of PP modification with MAH and itaconic anhydride (IAH) was observed. The initial grafting yield Rg has been experimentally determined and compared with a defined area of theoretical values of Rg. The extent of b-scission was significantly influenced by the structure and the concentration of peroxide, as shown by the results of MFR and the rheological curves of PP-g-MAH. The last part of the doctoral thesis is focused on the assessment of the combination of MAH and IAH as comonomers on the grafting yield. At first, the reference polymers were prepared using the solution polymerization of MAH, and IAH, and copolymerization of MAH with IAH. The reference polymers were analyzed by FTIR, DSC, WAXS to confirm the probable copolymerization of MAH and IAH. The dependence of the reaction enthalpy on the reaction time was observed using simulations of bulk polymerization of MAH, IAH and mixtures MAH and IAH "in situ" in isothermal calorimeter. PP was subsequently modified with a combination of MAH and IAH as comonomers in order to assess its effect on the grafting yield

Industrial catalysts used in commercial processes for the production of maleic anhydride are mainly Vanadium Phosphorous Oxide (VPO) catalysts. The VPO catalyst used is Vanadyl Pyrophosphate (VO)2P207 made from its precursor Vanadium Phosphorous Hemi-Hydrate VOHP04.O.5H20 in an non-aqueous medium. In order for the VPO catalyst to perform optimally, a metal promoter, Ru, was selected as the doping agent in this study. Four catalysts of different metal doping concentrations (undoped, 0.2%, 0.6% and 1%) were subjected to the oxidation of n-butane. Promoters are added to facilitate the oxidation of n-butane to maleic anhydride. n-Butane gas is now being used in many industrial processes, in fixed bed reactors to convert the gas to maleic anhydride. Catalysts were calcined under high temperatures under a nitrogen atmosphere. It was found that with an increase in reaction temperature, there was an increase in conversion of n-butane to maleic anhydride. Selectivity of the product also showed an increase with an increase in temperature at a Gas Hourly Space Velocity (GHSV) of 1960-2170hr-1. Catalysts were characterized using different techniques such as Electron Dispersive X-Ray Spectroscopy, Inductively Coupled Plasma-Atomic Emission Spectroscopy, Fourier Transform - Infra Red, Average Oxidation State, Brunauer Emmett and Teller (surface area), X-Ray Diffraction and Scanning Electron Microscopy. The 0.6% Ru promoted VPO catalyst showed to be most effective in terms of conversion, selectivity and yield, at a temperature of 450°C as compared to the other catalysts studied. The catalysts degenerated after being subjected to higher temperatures. The selectivity obtained by this catalyst was at 70.2% and the yield obtained was 37%. This study showed that with an increase in Ru up to a certain concentration (0.6%), an increase in selectivity and yield was observed, thereafter, with additional Ru doping, a decrease in selectivity and yield was obtained. / Thesis (M.Sc.)-University of Natal, 2003.

Co promoted and unpromoted vanadium-phosphorous-oxide (VPO) catalysts were synthesized via an organic route. The catalyst precursor was calcined and then conditioned in a reactor, forming the active vanadyl pyrophosphate, (VO)2P2O7, phase. Different promoter loaded catalysts were synthesized and their effect on the yield of maleic anhydride (MA) from n-butane oxidation was examined at different temperatures and gas hourly space velocities (GHSV). The catalysts were tested as a powder. The catalysts were examined in the oxidation of n-butane gas, over air as an oxidant, in a specially designed and constructed continuous flow, fixed-bed catalytic micro-reactor equipped with an on-line gas chromatography (GC) monitoring system. A thermal conductivity detector (TCD) was employed for carbon oxide monitoring and a flame ionization detector (FID) for all other products. The catalysts were characterised by X-ray diffraction (XRD) to determine the phases present in the precursor, calcined and used catalysts. The Brunauer-Emmet-Teller (BET) surface area was calculated for the different promoter loaded catalysts. Fourier transform infrared (FT-IR) spectra, via the KBr pellet method, and attenuated total reflectance (ATR) spectra were recorded to determine the anions present in the bulk and surface of the catalyst respectively. Energy dispersive X-ray (EDX) and inductively couple plasma-atomic emission spectroscopic (ICP-AES) techniques were employed to determine the elemental composition on the surface and in the bulk of the catalyst respectively. Scanning electron microscopic (SEM) images of the catalysts during different stages of their investigation were recorded. The average vanadium oxidation state (AV) in the bulk of the catalyst was determined via a titrimetric method. The catalysts were optimized to a high yield and selectivity of MA. The operating temperature, GHSV and promoter loading on the catalyst were the parameters that were changed during the testing of the catalyst. Different stages of the catalyst's life were characterised via the techniques mentioned above. The catalysts were monitored over a 200-hour period on average, usually taking approximately 24 hours to equilibrate. One such Co promoted catalyst yielded 45 % MA at 275°C and GHSV of 2878 hr-1 on equilibration, with an n-butane conversion of 73 %, whilst all previously reported VPO catalysts produce far lower MA yields at this temperature. / Thesis (M.Sc.)-University of Natal, Durban, 2002.

Este trabalho tem como escopo o desenvolvimento de um modelo matemático representativo do processo de enxerto de anidrido maleico em polietileno, processo conhecido como grafting, com o objetivo de prever as modificações no grau de enxerto e teor de gel. Neste processo utiliza-se um iniciador, geralmente um peróxido, para gerar radicais livres, os quais abstraem hidrogênio das moléculas do polímero, gerando radicais poliméricos. O anidrido maleico pode reagir com estes radicais poliméricos, enxertando-se à cadeia polimérica, ou com os radicais fragmentos do iniciador. O mecanismo inclui também as reações de terminação entre os diferentes tipos de radicais presentes. O teor de gel é calculado a partir do grau de formação de ligações cruzadas utilizando-se a aproximação de Charlesby-Pinner. As constantes cinéticas do modelo foram estimadas via regressão não-linear, usando dados experimentais obtidos na literatura, e o modelo foi validado com outros conjuntos de dados, também obtidos da literatura. O modelo obtido mostrou-se capaz de representar adequadamente os dados experimentais em diferentes condições. / The scope of this work is the development of a mathematical model that can represent the process of grafting of maleic anhydride in polyethylene. The objective of this model is to preview the main modifications in polymer structure, as degree of grafting and degree of gel. In this process, an initiator, generally a peroxide) is used to generate free radicals that can abstract hydrogen from the polymer molecules, producing polymeric radicals. Maleic anhydride can react with these polymeric radicals, resulting in grafted polymer chains, or with the initiator radicals. This mechanism includes termination reactions between the different types of radicals present. Gel content was calculated from the crosslinking degree using the approximation of Charlesby-Pinner. Kinetic constants of the model were estimated through non-linear regression, by fitting the model to experimental data taken from literature. The model obtained was further tested using other data sets obtained from literature. The developed model was able to represent adequately the experimental data under different conditions.

Dans l’optique du développement de procédés propres, cette recherche a consisté à étudier un procédé de réduction du dioxyde de soufre contenu dans des rejets gazeux industriels par absorption dans une solution de lavage contenant un oxydant particulier, le peroxyde d’hydrogène H2O2, qui oxyde irréversiblement le SO2 en acide sulfurique. C’est un procédé a priori intéressant puisqu’il génère des solutions d’acide sulfurique qui, si on parvient à les concentrer suffisamment par recyclage, peuvent être utilisées pour diverses applications industrielles, ou réinjectées dans le procédé produisant le polluant acide, tout résidu polluant liquide étant alors inexistant dans cette technique d’épuration de gaz. En vue de l’application de cette technique, notre travail a permis de progresser dans la connaissance du système SO2-H2O2-H2SO4 par une double étude portant sur la cinétique et la thermodynamique des phénomènes. Finalement, un modèle de dimensionnement assez général, valable dans une large gamme de conditions opératoires industrielles de concentrations en acide sulfurique et en peroxyde d’hydrogène de la solution de lavage et de température de l’effluent à traiter, a été développé et ce afin de réaliser les projets de n’importe quel type de contacteur (colonnes à films, à garnissage ou à pulvérisation) à condition bien entendu de les combiner aux caractéristiques de transfert propres à ces divers contacteurs. A titre d’exemple, nous avons dimensionné dans notre travail une colonne d’absorption à garnissage permettant d’épurer les gaz d’une fonderie de cuivre et produisant un acide sulfurique à 40 % en poids.