Dissertations / Theses on the topic 'Huiles lubrifiantes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 41 dissertations / theses for your research on the topic 'Huiles lubrifiantes.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Mieloszynski, Jean-Luc. "Etude et synthèse d'additifs pour lubrifiants." Metz : Université Metz, 2008. ftp://ftp.scd.univ-metz.fr/pub/Theses/1985/Mieloszynski.Jean_Luc.SMZ8514.pdf.
Full textKeromest, Catherine. "Synthèse, caractérisation et application aux huiles lubrifiantes d'additifs polymères phosphosoufrés." Paris 6, 1992. http://www.theses.fr/1992PA066525.
Full textMieloszynski, Jean-Luc. "Etude et synthèse d'additifs pour lubrifiants." Metz, 1985. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1985/Mieloszynski.Jean_Luc.SMZ8514.pdf.
Full textPrieri, Florence. "Mécanismes d'oxydation des huiles de base et des lubrifiants. Relations structures~performances." Aix-Marseille 3, 2006. http://www.theses.fr/2006AIX30007.
Full textThe engine lubricants must resist to the ageing and answer to the specifications of the car manufacturers. Formulated or not formulated oils were oxidized with a simulated ageing cell adaptable to a FTIR microscope in order to studied their behaviour vis-a-vis oxidation and to evaluate their structures~performances relationships. Thanks to spectrometric index, kinetics of oxidation could be built and allow the extraction of discriminating oxidation parameters. The deconvolution and the chemometric studies (Simplisma and 3D) of the spectra permit to establish a general oxidation mechanism. The study by regression methods permit to highlight relationships between the physicochemical data, the formulation of the lubricant and its oxidation resistance. This work made it possible to set up a innovating technique indicating to the formulators the structure and the additivation to hold in function expected performances
Lofficial, Gisèle. "Simulation en tribologie." Lyon, INSA, 1986. http://www.theses.fr/1986ISAL0008.
Full textDorenge, Justine. "Etude du comportement d'additifs polymères épaississants dans les huiles moteur." Thesis, Le Mans, 2018. http://www.theses.fr/2018LEMA1012.
Full textThe reduction of car fuel consumption is one of the biggest concerns for oil companies. It involves the reduction of friction between moving parts through the formulation of lubricants.A lubricant is composed of base oil and several additives used to improve the properties of engine oils. Polymeric compounds are used to limit the decrease of viscosity with temperatures to efficiently protect the motor. This type of additives, called Viscosity Index Improver (VII), is based on the swelling of polymer chains with temperature. The most important parameter in the lubricant formulation is the viscosity and its dependance on temperature. The aim of the work was to study the influence of recently developed families of VII additives in different base oils in ordrer to select the most efficient type of polymer for engine lubricant uses, by understanding the molecular mechanisms responsible of the VII behavior. Various polyalkylmethacrylates were investigated to establishing the rheological properties of the solutions, namely as a function of temperature (dependence of intrinsic viscosity). For a given base oil, the efficiency of a VII varies with its chemical structure, its molecular weight and its concentration. Then, tribological properties were investigated using standard tests with the aim to obtain an overview of the lubricant's behavior under pressure. We also considered the degradation of this kind of polymers in a representative test in order to check the performance's durability. Degradation and tribological behaviors were rationalized in terms of volume occupied by polymer chains
Petitalot, Blandine. "Elaboration et propriétés physico-mécaniques de graisses lubrifiantes améliorées par des polymères." Rouen, 2001. http://www.theses.fr/2001ROUES010.
Full textRodriguez, Chloé. "Filtration tangentielle assistée par C02 sous pression : problèmes de mise en œuvre et application au recyclage des huiles usagées." Montpellier 2, 2002. http://www.theses.fr/2002MON20158.
Full textHardivilliers, Wallerand d'. "Lubrification des moteurs d'automobiles : Espacement des intervalles de vidange." Ecully, Ecole centrale de Lyon, 2005. http://www.theses.fr/2005ECDL0046.
Full textAll along this thesis, we tried to understand why do we use our engines. Oil drain interval parameters have been studied. We have analised soot (chemical composition, hardness) to understand their real impact on wear. A nex wear theory has been developed and we found some links with combustion parameters. We have studied ZnDTP and we found that it could be important to use it as a new oil drain interval parameter as one can made better simulations. Fuel dilution has been studied too and did not reveal any impact on wear
Tran-Minh, Anh-Kiet. "Conversion catalytique de dérivés de l'huile de colza : une nouvelle voie de valorisation chimique." Vandoeuvre-les-Nancy, INPL, 2002. http://www.theses.fr/2002INPL002N.
Full textŞtefănoiu, Florina. "Synthèse et caractérisation d'ASAs - Anhydrides Alkényles Succiniques - et de dérivés d' ASAs : application à l'industrie des lubrifiants." Toulouse, INPT, 2007. http://ethesis.inp-toulouse.fr/archive/00001205/.
Full textThe present work is a study of the vegetable oil derivatives for non food purposes. In the beginning our studies focused on the chemical reactivity between the esters of the fatty acids and the maleic anhydride, in order to obtain Anhydrides Alkényles Succiniques (ASAs). The obtained results allowed us to point out the existence of two reaction mechanisms which are parallel and independent. The following studies were performed on the mono-derivation of the ASAs with nitrogen molecules (N-derivation) and phosphorous molecules (P-derivation) or on the double-derivation (NP-derivation) of the ASAs. The methods we used lead with an optimal yield to new molecules. Each of these compounds confers at least one interesting property in the lubricants uses : anti-wear, extreme pressure, flow point, solubility in the vegetable and mineral bases, but none presents all the properties at the same time
Minfray, Clotilde Martin Jean-Michel. "Réactions tribochimiques avec le dithiophosphate de zinc." [S.l.] : [s.n.], 2004. http://bibli.ec-lyon.fr/exl-doc/cminfray.pdf.
Full textKasai, Moritsugu. "Réduction du frottement et amélioration de la fiabilité de la lubrification des paliers avec des huiles de moteurs automobiles." Phd thesis, Université de Poitiers, 2010. http://tel.archives-ouvertes.fr/tel-00477348.
Full textMansuy, Hervé. "Etude des interactions entre additifs anti-usure et dispersants. Influence sur la formation des films limites." Paris 6, 1995. http://www.theses.fr/1995PA066384.
Full textLomege, Juliette. "Synthèse d'additifs améliorant d'indice de viscosité issus de poly(méthacrylate de n-alkyle)s d'acides gras et leur application dans des huiles lubrifiantes." Electronic Thesis or Diss., Montpellier, Ecole nationale supérieure de chimie, 2018. http://www.theses.fr/2018ENCM0008.
Full textAbstract : Lubricating oils are formulated with "Viscosity Index Improver" (VII) additives in order to limit viscosity variation with temperature and thus maintain lubricity at high temperatures. VIIs are polymers of high molar masses which display a reduced solubility in oil at low temperatures resulting in an improvement of the polymer contribution on oil’s viscosity in temperature via the "coil expansion" mechanism. Among them, poly(n-alkyl methacrylate)s (PMA)s largely dominate the VII additives market but are mainly derived from petroleum resources. In such context combined with the increasing production of biolubricants, it seems interesting to develop biobased additives with similar chemical structures and properties than current PMAs. In order to achieve that purpose, fatty acids and their derivatives recently appeared as the perfect renewable resources since they are abundant in oil plants, cheap, compatible with base oils, functionalizable and they exhibit good natural lubricating properties. Nevertheless, they display a low reactivity through radical polymerization. Therefore, several available fatty acids have been functionalized with methacrylate groups to afford suitable monomers and the resulting polymers have demonstrated promising properties as VII in a mineral oil. The more performant VII was the high molecular weight poly(2-(methacryloyloxy)ethyloleate obtained by free radical polymerization whose properties have been optimized by grafting alkyl thiols on the internal unsaturation of the monomer from which it is derived. On the other hand, the same polymer demonstrated a strong affinity with a triglyceride lube oil due to their close structure avoiding the expansion of its rheological properties as VII in this type of oil. New polymeric structures with reduced solubility in triglyceride oils have therefore been developed to prepare suitable VIIs. In a first strategy, epoxy groups were incorporated into the structure of the poly(2-(methacryloyloxy)ethyloleate while in a second strategy, the monomer from which it is derived was copolymerized with comonomers of insoluble fatty amides in the reference triglyceride oil. The resulting (co)polymers have shown a similar rheological behavior in temperature than the current VII additives. Thus, the polymeric structures developed in this work represent promising alternatives to the use of current petroleum-based VII additives for applications in both mineral oils and triglyceride-type biobased oils
Duong, Sandrine. "Modélisation de la dégradation de l’huile dans un turboréacteur." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS617.
Full textHigher operating temperatures and lower oil consumption in future-generation of turbo engines may result in greater oil degradation than current engines. It is therefore necessary to follow the evolution of this degradation. This thesis aims to understand the oxidation by free radical chain reactions of a neopolyol ester lubricant in a turbo engine, focusing more particularly on the influence and behaviour of the two antioxidants additives (PAN, DODPA). Accelerated oxidation tests were carried out on the PetroOxy device in order to identify the degradation products, to prioritize the role of the antioxidant additives under these test conditions and to optimize the characterization techniques (HPLC and FTIR) used during this thesis. The decomposition into several representative mixtures of the lubricating oil made it possible to demonstrate that the consumption of the PAN was higher than that of DODPA. In fact, the products formed by the PAN are final products (the quantity of which keeps increasing over time) while the DODPA is able to produce compounds that also have an antioxidant effect. These will form and react with free radicals, which will slow down the consumption of the original antioxidant (DODPA). Studies conducted on the ageing of thin film oil on a flat plate have helped to better understand the mechanisms in an environment closer to that of the engine. The effectiveness of DODPA regarding PAN has been highlighted. In addition, the synergistic effect due to the combination of these two antioxidants in the oil has been demonstrated. Finally, the study on the influence of the parameters made it possible to calculate the kinetic constants useful for the formulation of the kinetic model, which provides the prediction of the consumption rate of the antioxidants on an inclined plate. A test bench reproducing the operating conditions of an oil system present in a turbo engine was designed and built during this thesis. The purpose of this assembly is to distinguish the 3 modes of ageing of the lubricant, which are : bulk oil (in the tank and the pipes), mist (at the exit of the bearings) and thin film (flowing on the walls of the enclosures) in order to study the oxidation mechanisms governing the 3 states. Finally, the comparison of the results obtained for each mode of ageing studied made it possible to determine a minimum antioxidant content required in the lubricant (i.e. 30 %) so that the neopolyol ester is not affected by the oxidation, in others words, the lubricant will keep a sufficient quality to ensure its operation in the turbo engine
Gracia, Nadège. "Oxydation des lubrifiants moteurs suivie par spectroscopie infarouge et analyse chimiométrique." Caen, 2010. http://www.theses.fr/2010CAEN2071.
Full textMaintaining the quality of lubricants is essential because of their key role in machine duration and performance. Oxidation is one of the main causes of oil degradation. To prevent and reduce the consequences of this phenomena in the best possible way, mechanisms must be determined and well understood. An experimental system was built to reproduce, at the lab-scale and in an accelerated mode, the oxidation process of lubricating base oils under temperature close to those existing under working conditions. Mid-infrared spectroscopy has been chosen for on-line monitoring of the chemical changes happening along the process. To understand the oxidation evolution, the spectroscopic data recorded have been analysed with factorization techniques such as Principal Component Analysis (PCA), which has shown the action of iron as catalyst. The use of Multivariate Curve Resolution – Alternating Least Squares (MCR-ALS) method allowed to extract chemical information about the evolution of a substituted diphenylamine antioxidant during the induction period
Jullien, Yannick. "Synthèse de dérivés phosphosoufrés potentiellement biodégradables : formulation d'un lubrifiant à base d'huile de colza." Metz, 1998. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1998/Jullien.Yannick.SMZ9815.pdf.
Full textLe, Coq Laurence. "Mise en oeuvre et modélisation de médias fibreux pour la filtration d'huile." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0169.
Full textLecompte, Matthieu. "Etude expérimentale des sprays d’huile dans un moteur à combustion interne : Influence de l’écoulement de blow-by et participation à la consommation d’huile." Rouen, 2007. http://www.theses.fr/2007ROUES069.
Full textIn the face of customer requirements in terms of oil consumption reduction and pollutant emissions, it becomes important to understand the behavior of oil in the combustion chamber environment. The work carried out in the present Ph. D. Concentrates mainly on the drop-size distribution characterization of oil sprays produced through the ring gap by the blow-by-flow (air flow taking place between the piston and the liner during the compression stroke) and on the determination of their participation to the total lubricant consumption. To achieve this, a two-step experimental study was conducted. An atomizer reproducing the atomizing phenomena through a ring gap was first realized and studied in the laboratory. The drop-size distribution of the produced oil sprays were measured thanks to the use of several measurement techniques as a function of the lubricant flow rate and the upper air pressure. Second, an experimental investigation conducted on a car engine investigated the oil spray drop-size distribution at several locations. Furthermore, for each working condition, measurements of oil consumption in real time were achieved using a SO2 tracer technique. In these two studies, the oil-spray drop-size distributions were successfully modeled by an approach based on the Maximum Entropy Formalism. Among the most important results, this study reports that the drop-size distribution of oil-sprays produced by blow-by depends on the engine regime and load. Furthermore, for some working conditions, this oil-spray production is majority in the return flow whose influence on the total oil consumption was evidenced
Loyal, Akshay. "Étude expérimentale et modélisation de la dégradation d'huiles de lubrification aéronautiques." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS169.
Full textLike all sectors of transportation, the aviation industry evolves with regards to new environmental concerns. The focus is set on reducing fuel consumption notably by reducing the overall mass of the aircraft thanks to lighter composite materials but there are also concerns for atmospheric emissions of harmful particles, gaseous pollutants, or even liquid losses (unburned hydrocarbon, nitrogen oxides or even lubricant)In fact, during flight, jet engines lose oil in the atmosphere. This oil consumption induces regular top-ups with fresh lubricants and a balance is therefore reached between the oxidizing lubricant in the circuit and the fresh top-ups. This mechanism maintains a healthy oil quality in the lubrication circuit of the jet engine and allows it to properly lubricate and cool the rotating partsHowever, two trends can be observed in the jet engine industry : - The first is the reduction of atmospheric emissions, notably oil emissions by lowering the oil consumption of engines, for environmental concerns but also to reduce the top-up frequency and the associated costs ; - The second trend is the ever-increasing performance gains. One lever on the lubrication circuit is to reduce the mass of heat exchangers designed to cool the lubricant at the cost of having to operate with higher oil temperaturesThese two trends push the lubricants oxidation to more extreme conditions: less oil consumption implies less frequent top-ups while also operating at higher temperatures which increases the rate of oxidation of the oil. Such conditions are currently outside the experimental knowledge of Safran and motivates studies aiming to better understand oil degradation
Papin, Géraldine. "Synthèse, caractérisation et évaluation de nouveaux additifs de tenue à froid des gazoles et fiouls domestiques." Bordeaux 1, 2008. http://www.theses.fr/2008BOR13569.
Full textNguyen, Thi Hang Nga. "Conception et synthèse de polymères pour le domaine lubrifiants." Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066763.
Full textControlling the viscosity of apolar solutions as a function of temperature is a key issue in many industrial applications, such as high performance lubricating oils. Here, we describe a new approach to control the viscosity of such formulations as a function of temperature. For that purpose, we designed two sets of functional copolymers that have temperature dependant solvent affinity as well as the ability to reversibly connect through the formation of dynamic covalent boronic ester bonds. Those macromolecules were synthesized by controlled radical polymerization, which allowed preparing random copolymers with adjustable molecular weight, solvent affinity, and functionality. Rheological studies of the linear viscoelasticity and flow behavior were conducted to exemplify the efficiency of these systems to control the viscosity of organic solutions as a function of temperature. By manipulating the composition and functionality of the copolymers it should be possible to precisely adjust the temperature for which the system will respond as well as the resulting viscosity
Osowiecki, Raoul. "Evolution des additifs non polymériques des huiles moteur et influence sur leurs performances en service : aspects moléculaires et cinétiques." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAF054.
Full textCurrent technologies used for diesel engines lead to an accelerated degradation of the non-polymeric additives from lubricants, such as antioxidants, antiwear, friction modifiers and detergency additives.Our work intends to identify the nature of the chemical modifications undergone by such additives during engine functioning. In this respect, an analytical protocol has been developed in order to investigate qualitatively and quantitatively these compound families in engine oils. Following this, the analytical methodology has then been used to study oils altered during engine bench tests and laboratory experiments. Thus, the evolution of the chemical composition, the nature of the degradation products and the alteration processes have been considered. Furthermore, kinetic models have been established for each family of additives.It appears from this study that the processes implied in the alteration of the additives during laboratory tests do not reproduce those existing while engine running. Further laboratory experiments are needed in order to develop tests mimicking more closely the conditions occurring during engine functioning
Minfray, Clotilde. "Réactions tribochimiques avec le dithiophosphate de zinc." Ecully, Ecole centrale de Lyon, 2004. http://bibli.ec-lyon.fr/exl-doc/cminfray.pdf.
Full textThe principal function of lubrificating oil is to control friction and wear of materials, generally by minimizing the metallic contact between antagonistic surfaces. In severe conditions, the base oil cannot provide this function. Additive chemically active are generally added. They interact with metallic parts to form protective films called tribofilms (about 50 nm thickness). This study deals with the mechanisms of action of an anti-wear additive : the zinc dithiophosphate (ZDDP). Because of pollution problems, phosphorus and sulphur, present in the ZDDP molecule, must be limited in the lubricants. In order to propose nex anti-wear additives, it is important to study the ZDDP mechanism of action. In this work, we identified a certain number of chemical reaction activated by friction in presence of ZDDP tribofilm tranks to in-situ analyses on friction surfaces
Youbi-Idrissi, Mohammed. "Impact de l'huile de lubrification sur les performances thermodynamiques des pompes à chaleur réversibles." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2003. http://tel.archives-ouvertes.fr/tel-00011290.
Full textFernandes, Mendonça Ana Catarina. "Simulations moléculaires d'une nouvelle classe de liquides ioniques basés sur la fonction ammonium pour l'utilisation potentielle en tant qu'huiles lubrifiantes respectueuses de l'environnement." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2013. http://tel.archives-ouvertes.fr/tel-00857336.
Full textMartin, Gael. "Altération des constituants non-polymériques des lubrifiants (additifs et base hydrocarbonée) lors du fonctionnement des moteurs : rôle de la nitroxydation." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAF009.
Full textAn alteration laboratory protocol of lubricants by NO2 has been developed in order to investigate the effects of nitroxidation on base oil and additives from engine lubricants, and to understand the different mechanisms involved. The structure of alteration products and their transformation pathways have been proposed, as well as the factors that control the degradation kinetics of the additives. Interactions between lubricant constituents have been identified at the degradation kinetic level as well as the level of the alteration products formed, notably by means of an experimental design. The fate of lubricants in the laboratory experiments does not exactly match that observed in the case of engine tests, notably regarding the absence of formation of some degradation products. However, the interactions controlling the degradation kinetics of lubricant additives are close between laboratory experiments and engine tests
Chauveau, Vanessa. "Le pouvoir lubrifiant des nanotubes de carbone." Phd thesis, Ecole Centrale de Lyon, 2010. http://tel.archives-ouvertes.fr/tel-00601121.
Full textDelaval, Damien. "Développement et caractérisation de systèmes intumescents retardateurs de flamme pour polypropylènes recyclés issus des véhicules usagés." Electronic Thesis or Diss., Lille 1, 2009. http://www.theses.fr/2009LIL10015.
Full textThe impact of recycling and pollutants (engine oil (EO) and ethylene glycol (EG)) on the intrinsic properties of polypropylene-based materials coming from end-of-life cars was investigated. Recycling (limited here to six extrusion cycles) is not detrimental to the mechanical properties of the polymeric matrices. The crystallization kinetics study realized on the polluted polymers showed that the presence of EG delays crystallization. The degradation kinetics allowed to simulate and quantify the different degradation steps of the materials. Pollutants and recycling also lead to an improvement of the reaction to fire of our copolymer, especially in the case of EO-containing samples. The second part of the work was devoted to the study of the flame retardant properties of our materials provided by ammonium polyphosphate (APP) with or without zinc borate (ZB) (synergistic agent)). In all cases recycled and polluted materials show satisfying performances. It was found that the efficiency of the protective barrier provided by the char is governed by the rapidity of its formation and its thermal conductivity which are positively influenced by EO (with APP/ZB) and recycling (with APP) (increase of the formation rate and decrease of the conductivity). Chemical characterization of the structures formed in a fire scenario reveals the formation of a phosphocarboneous structure containing polyaromatics, pyrophosphates and phosphoric acid and when zinc borate is used, borophosphates which can reinforce the intumescent structure
Avellan, Anne-Virginie. "Valorisation non alimentaire des huiles de friture usagées (HFU) en biolubrifiants par transestérification catalytique." Poitiers, 2005. http://www.theses.fr/2005POIT2307.
Full textThe market of used frying oils (UFO's) collection in Europe is estimated to about 350 000 tons a year. Since the dioxin crisis in 1999, the main recycling ways of this raw material, considered as a waste, concern the oleochemical applications namely the production of biodiesel and fatty acids. In this context, the European CRAFT VALUIL project led to a new application of UFO's as environmentally friendly biodegradable lubricants in applications such as demoulding agents, industrial gear boxes oils and hydraulic fluids. The synthesis of biolubricant bases is carried out according to an integrated catalytic transesterification process: methanolysis of UFO's followed by a transesterification in presence of trimethylolpropan. The lubricant performances synthesised at laboratory and pilot scales as well as a first process cost assessment have strongly encouraged the industrial partners to go on this project towards an industrial development
Chaveroux, Damien. "Relations structures-propriétés de polymères améliorants de viscosité dans les lubrifiants moteur." Thesis, Le Mans, 2015. http://www.theses.fr/2015LEMA1002.
Full textThe development of lubricants is a real challenge for the automotive and the petroleum industries to reduce the energy losses in engines due to frictions. The viscosity is the main parameter that the lubricant formulators can vary to reduce the frictions. This PhD deals with the role and mode of actions of viscosity modifier polymers (VM polymers) in lubricants.The purpose of this PhD is to correlate the study at the molecular scale with the macroscopic properties and the lubricant performances in order to orient the formulators towards one or several target molecules which could present the best properties.This work consisted in characterizing hydrogenated Poly-diene-styrene (P-diene-SH) and ethylene-propylene-copolymers (EPC).First, studies on the structure of VM polymers and on rheological properties of the solutions have shown the influence of the different chemical structures and polymer architectures on their rheological properties. This study was carried out on a large scale of temperatures (-20 à +135°C), shear rates (0 à 107s-1) and concentrations leading to characterizations under conditions corresponding to practical conditions.Secondly, these rheological properties were correlated with frictions coefficients and the film thickness in a sphere/plate contact in tribology.Finally, the ability of the polymer chains to break when a high shear rate was applied in a continuous or pulsed flow was studied and related to the chains configurations of the VM polymer and their structure.All these data were further used to propose a chemical structure and a polymer architecture leading to viscosity improved properties, a good resistance to degradation and a satisfactory behavior in tribology
Delaval, Damien. "Développement et caractérisation de systèmes intumescents retardateurs de flamme pour polypropylènes recyclés issus des véhicules usagés." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10015/document.
Full textThe impact of recycling and pollutants (engine oil (EO) and ethylene glycol (EG)) on the intrinsic properties of polypropylene-based materials coming from end-of-life cars was investigated. Recycling (limited here to six extrusion cycles) is not detrimental to the mechanical properties of the polymeric matrices. The crystallization kinetics study realized on the polluted polymers showed that the presence of EG delays crystallization. The degradation kinetics allowed to simulate and quantify the different degradation steps of the materials. Pollutants and recycling also lead to an improvement of the reaction to fire of our copolymer, especially in the case of EO-containing samples. The second part of the work was devoted to the study of the flame retardant properties of our materials provided by ammonium polyphosphate (APP) with or without zinc borate (ZB) (synergistic agent)). In all cases recycled and polluted materials show satisfying performances. It was found that the efficiency of the protective barrier provided by the char is governed by the rapidity of its formation and its thermal conductivity which are positively influenced by EO (with APP/ZB) and recycling (with APP) (increase of the formation rate and decrease of the conductivity). Chemical characterization of the structures formed in a fire scenario reveals the formation of a phosphocarboneous structure containing polyaromatics, pyrophosphates and phosphoric acid and when zinc borate is used, borophosphates which can reinforce the intumescent structure
Labet, David. "Détermination des critères influents et mesurables permettant de caractériser l'évolution du vieillissement des huiles moteur en service : contribution à la conception d'un indicateur de vidange intelligent." Bordeaux 1, 2003. http://www.theses.fr/2003BOR12656.
Full textTo guarantee engin effectiveness, periodic oil change are recommended without specific knowledge of the real condition of lubricant ageing. Today, in order to assure a sufficient safety margin for customers, oil change intervals are determined, among others, from endurance tests using vehicules with the more critical engine and very hard road conditions. When oil is changed, lubricant may have a fonctional potential non-negligible. So it is essential to know with precision the extent of degradation of the lubricant in order to lighten the maintenance unit and to reduce the cost in service. This study give prominence to several influential criterion of lubricant degradation process in service as viscosity, acidity, basicity, antioxidant reserve and fuel dilution. Actions of progress to be considered concerning the evolution of these criterions to contribute to the development of oil condition sensor are respectively the control of viscosity additive depletion, the adjustment of a accurate and reliable method to measure oxidation (PAI), the determination of a minimal threshold of basicity for new generation low rate ashes lubricants, the establishment of a new oil change criterion from the determination of antioxidant reserve and finally the acceptance of a maximum percentage of fuel dilution as oil drain criterion. The deliver proposed are a better understanding of the ageing process with the influence of group IV base oils on mineral lubricant, the identification of oil drain criterion to progress in order to their adaptation on vehicules and their validation on new generation lubricants
Wiromartono, Wiranto. "Étude des relations entre la structure chimique de quelques additifs organiques soufrés et leurs propriétés extrême-pression et les dérivés soufrés en lubrification." Paris 6, 1986. http://www.theses.fr/1986PA066154.
Full textLacaze-Dufaure, Corinne. "Fractionnement du tournesol oléique : expression et transformations chimiques des triglycérides de graines en esters lubrifiants et adjuvants en réacteur conventionnel et réacteur bi-vis." Toulouse, INPT, 1998. http://www.theses.fr/1998INPT010C.
Full textThere is nowadays a great development of high oleic sunflower cultivation in Europe. Seeds containing 80-90 % of oleic acid triglycerides are available for non-food applications. Our works are first about sunflower seeds pressing in a twin-screw extruder. The oil extraction can be increased by a co-injection of acidic alcohol. Phosphoric acid mixed to the alcohol enhances the oily spherosomes lability. Then, transesterification of the triglycerides from the oleic oil, alcoholysis of sunflower methyl oleate and esterification of oleic acid are studied. We used 2-ethyl hexanol as alcohol and phosphoric acid as catalyst. This catalyst showed a great catalytic activity due to its repartition between the hydrophobic phase (triglycerides, alcohol, esters) and the hydrophilic phase (water, glycerine). A process to produce fatty esters made from several alcohols and fatty substances is proposed. Finally, high oleic sunflower seeds are used as a chemical substract. Both acidic and basic catalysts are used. 2-ethyl hexanol and phosphoric acid are choosen to produce pure fatty esters while basic catalysts (NaoH, EtONa) are getting simultaneously to the production of fatty esters and oleic soaps. These studies were made in a batch reactor and in a twin-screw extruder used as a thermochemical reactor. The fatty esters and the oleic blends prepared have been tested in lubrication. These studies are protected by three international and french patents
Essono, Abaga Ange-Godefroy. "Valorisation non alimentaire des huiles de friture usagées en tant que biolubrifiants." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0313.
Full textThe applied research project focused on the valuation of used frying oils as bio-lubricant for chainsaw. Those collected in the various restaurant chains oils have a high content of polar compounds , high acidity , a great variability in their composition , fatty acids on different brands of vegetable oils . These mixtures of vegetable oils (rapeseed, sunflower , peanut, palm , coconut ) , already valued in the biofuels , have interesting physicochemical properties ( viscosity , biodegradability , fatty acid composition ) that would allow them to compete with lubricants mineral or vegetable that is found on the market, particularly in the forestry sector origin . A method of ceramic membrane ultrafiltration has reduced content of polar compounds and the subsequent acidity of the deep frying process , while reducing the clogging phenomenon . The use of response surface methodology has helped to optimize the parameters of temperature, pressure, porous membranes, to improve filtration rates . The formulation of this biolubricant from the mixture of oils obtained optimized plan mixtures led to the production of a product of ISO 150 grade which features " spinning ", " stickiness " and " pour point " meet the specifications . A study of biodegradability according to OECD 301B showed that formulated oil is 90% biodegradable , low toxicity tests according to OECD 201, 202, 203, and does not show allergenicity
Hamad, Berna. "Transestérification des huiles végétales par l’éthanol en conditions douces par catalyses hétérogènes acide et basique." Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10271/document.
Full textBiodiesel is a mixture of mono-alkyl esters used as alternative fuel. It can be obtained by transesterification of vegetable oils or animal fats with light alcohols.The objective of this work is the research of acid and basic solid catalysts able to promote the transesterification reaction of rapeseed oil with ethanol in conditions as mild as those used in homogeneous base catalysis. For this, two series of solid acids and bases were prepared and characterized by various characterization techniques (TGA-DTA, XRD, Isothermal N2). Calorimetry and Infrared Spectroscopy have also been used to characterize acid and basic properties. Correlations between initial activity and the acidic or basic properties of these catalysts have been investigated. The influence of the main reaction parameters was examined on the most active acid and basic solid. A comparative kinetic study then allowed us to propose reaction mechanisms. Finally the in situ valorisation of glycerol, a by product of the reaction, was carried out.We have shown that the cesium salt of 12-tungstophosphoric acid catalyst is the most active among the solid acids studied. This is explained by the presence of strong BrØnsted acid sites that are able to promote the reaction under mild temperature conditions. This catalyst is capable of achieving in situ etherification of glycerol with ethanol. In base catalysis, the newly prepared catalyst, zirconia exchanged with Cesium, is the most active catalyst among the solid bases studied. This catalyst is stable in the reaction medium after removal of the labile Cs species by hot washing. Comparison of the two catalysts shows that the base catalysis is much faster than acid catalysis. A kinetic comparative study allows us to propose mechanistic differences between these two types of catalysts
Diew, Mohamadou Bocar. "Contribution à la compréhension des mécanismes d'action des additifs modificateurs de frottement et du couplage additif/surface dans tous les régimes de lubrification." Thesis, Ecully, Ecole centrale de Lyon, 2013. http://www.theses.fr/2013ECDL0042/document.
Full textThe combustion engine used in automotive industry is constantly changing for economic and ecological reasons. To achieve low fuel consumption and pollutants emissions, one of research axes studied is the reduction of the mechanical friction loss of the motor which constitute 15-20 % of the total energy consumption of the engine. 50% of these come from friction contacts cylinder /piston rings and conrod bearing. Thereby understanding of tribology of the contact, optimizing lubrication and lubricants aging become paramount. The objective of this thesis is to study the mechanisms of lubrication of these contact (piston ring/cylinder and conrod bearing), and in particular to understand the influence of the additive coupling surface and material in the different lubrication regimes. This will answer the question : how to control the friction and wear by controlling the chemistry of the lubricant, the topography and the material ? The experimental approach chosen is based on the analysis of the tribological behavior of two friction modifiers additives ashless at first time, and on the impact of material and finally the influence of topography on the second time. XPS Analysis of the evolution of the coefficient of friction and wear track under boundary regime have enabled to identify mechanisms to reduce friction induced by the two modifiers studied
Zhu, Shucai. "Etude des traitements physico-chimiques d'épuration des émulsions d'huile de coupe : influence de leur formulation." Toulouse, INSA, 1990. http://www.theses.fr/1990ISAT0001.
Full textWerda, Ben Slima Sana. "Influence de la conception d'un outil de fraisage dédié à la microlubrification (MQL) sur l'interaction outil-matière-lubrifiant : études expérimentales et numériques." Thesis, Tours, 2016. http://www.theses.fr/2016TOUR4030/document.
Full textIn machining industry, manufacturers tend to limit conventional lubrication and are moving increasingly towards Minimum Quantity Lubrication (MQL) for economic and ecological reasons, and with a view to safeguarding operator health and safety. A very small amount of lubricant at low pressure requires optimized design of the tools internal channels in order to minimize pressure drops and gain benefit from MQL. First, a literature review introduces the study by presenting the benefits induced by switching to MQL. Thereafter, some tool designs with internal lubrication for rake face or flank face lubrication are presented