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Synthèse de surfactifs à base de polyoxazoline : propriétés physicochimiques et formulation / Synthesis, properties and formulation of surfactants based on PolyoxazolineGiardi, Chloé 30 November 2011 (has links)
Nous décrivons dans ce manuscrit la synthèse et l'étude de surfactifs à base de poly(2-méthyl-2-oxazoline) et de corps gras. Pour cela, deux voies de synthèse ont été réalisées. La première qui consiste à amorcer la polymérisation avec un alcool gras tosylé. La deuxième voie de synthèse a été réalisée en amorçant la polymérisation par un alcane iodé. Les surfactifs ainsi obtenus ont une chaîne grasse saturée ayant douze ou dix-huit atomes de carbone et des longueurs de chaînes polymères variables.Ces surfactifs sont examinés afin d'évaluer leur aptitude à la formulation. Ainsi, la valeur de leur concentration micellaire critique a été déterminée par tensiométrie et spectrofluorimétrie. Ensuite, l'évaluation de leurs pouvoirs mouillant et moussant, de leur HLB, de leur température de point de trouble… ont été déterminés afin de les comparer avec leurs homologues POE, les Brij®. Dans l'optique d'une application à la formulation, des tests d'évaluation de leur toxicité ont également été réalisés. Enfin, des préparations cosmétiques ont été formulées, à base de ces surfactifs et des Brij®. Parallèlement, une étude a été menée démontrant l'intérêt du carbonate de glycérol tosylé comme amorceur de la polymérisation de la 2-méthyl-2-oxazoline. Cet amorceur a permis de fonctionnaliser les polyoxazolines en extrémité de chaîne par des fonctions terminales (hydroxy)uréthane. / In this manuscript, we describe the synthesis and the study of surfactants based on poly(2-methyl-2-oxazoline) and vegetable oil derivatives. Two ways for the synthesis are realized. The first path consists to initiate the polymerization with a tosylate fatty alcohol. The second synthetic route was realized by initiating the polymerization by an iodoalkane. The obtained surfactants have au saturated fatty chain with twelve or eighteen carbon atoms and various lengths of polymeric chain. This surfactants are reviewed to assess their suitability for the formulation. Thus, the value of their critical micelle concentration was determined by tensiometry and spectrofluorimetry. After, the evaluation of their wetting and foaming powers, their HLB, their cloud point temperature… was determinded in order to compare with their homologous POE, the Brij®. In the context of an application in the formulation, evaluation tests of toxicity were also made. Next, cosmetic preparations were realized, based on this surfactants and Brij®. In parallel, a study was conducted to demonstrate the tosylate gycerol carbonate interest as initiator in the 2-methyl-2-oxazoline polymerization. This initiator enable to fonctionalize the polyoxazoline in the chain end with (hydroxy)uréthane terminal function.
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The Effect of Anionic and Mixed (Anionic/Nonionic) Surfactant System on BTEX-Polluted Soil RemediationWang, Chi-Che 29 August 2000 (has links)
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Nejoninės paviršinio aktyvumo medžiagos (Pam) ir vario (II) jonų sorbcija aktyvintąja anglimi / The sorption of nonionic surfactant and copper (II) ions on activated carbonLavrinovič, Ana 13 June 2006 (has links)
The sorption of nonionic surfactant oxyethylated alcohols Lutensol AO – 10 and Cu (II) ions on activated carbon AquaSorb HS has been investigated. The kinetic investigations have revealed that the sorption of nonionic surfactant was the sufficiently slow process and required 7 days to reach equilibrium. The equilibrium sorption of the Cu (II) ions was attained within 24 h. ...
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Nonionic surfactants : A multivariate studyUppgård, Lise-Lott January 2002 (has links)
In this thesis technical nonionic surfactants are studied using multivariate techniques. The surfactants studied were alkyl ethoxylates (AEOs) and alkyl polyglucosides (APGs). The aquatic toxicity of the surfactants towards two organisms, a shrimp and a rotifer, was examined. The specified effect was lethality, LC50, as indicated by immobilisation. In a comparative study, the LC50 values obtained were used to develop two different types of model. In the log P model the toxicity was correlated to log P alone, while in the multivariate model several physicochemical variables, including log P, were correlated to the toxicity. The multivariate model gave smaller prediction errors than the log P model. Further, the change in reactivity when a surfactant mixture was added to dissolving pulp under alkaline conditions was studied, using the amount of residual cellulose as a measure of the reactivity. Ten AEO/APG mixtures were tested, and the mixture with greatest potential was studied in more detail. An optimum in the amount of added surfactant was found that seems to coincide, according to surface tension measurements, with the CMC.
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Toxicological Impact of Agricultural Surfactants on Australian FrogsMann, Reinier Matthew January 2000 (has links)
Surfactants are one of the more ubiquitous contaminants in aquatic systems. Their importance as toxic components of pesticide formulations has, however, been largely overlooked. Amphibians particularly, as inhabitants of shallow, temporary and often lentic aquatic environments may be at risk from exposure to these chemicals when they enter aquatic systems. This thesis presents data on the toxicity of surfactants to amphibians. Several experimental exposures were conducted with embryo-larval, tadpole and adult developmental stages of the Australian species- Crinia insignifera, Helcioporus eyrei, Limnodynastes dorsalis and Litoria moorei and the exotic species- Bufo marinus and Xenopus laevis. Animals were variously exposed to glyphosate formulations that contain a high proportion of nonionic surfactants, or commercial pesticide wetting agents (alcohol alkoxylate and nonylphenol ethoxylate (NPE) surfactants). Feeding stage tadpoles of C.insignifera, H. eyrei, L. dorsalis and L. moorei were exposed to three commercial glyphosate formulations, glyphosate isopropylamine and glyphosate acid in static-renewal acute toxicity tests. The 48-h LC50 values for Roundup Herbicide (MON 2139) tested against tadpoles of C. insignifera, H. eyrei, L. dorsalis and L. moorei ranged between 8.1 and 32.2 mg/L (2.9 and 11.6 mg/L glyphosate acid equivalent (ae)), while the 48-h LC50 values for Roundup Herbicide tested against adult and newly metamorphosed C. insignifera ranged from 137-144 mg/L (49.4-51.8 mg/L ae). / Touchdown Herbicide (4 LC-E) tested against tadpoles of C. insignifera, H. eyrei, L. dorsalis and L. moorei was slightly less toxic than Roundup with 48-h LC50 values ranging between 27.3 and 48.7 mg/L (9.0 and 16.1 mg/L ae). Roundup Biactive (MON 77920) was practically non-toxic to tadpoles of the same four species producing 48-h LC50 values of 911 mg/L (328 mg/L ae) for L. moorei and >1000 mg/L (>360 mg/L ae) for C. insignifera, H. eyrei and L. dorsalis. Glyphosate isopropylamine was practically non-toxic producing no mortality amongst tadpoles of any of the four species over 48 h, at concentrations between 503 and 684 mg/L (343 and 466 mg/L ae). The toxicity of technical grade glyphosate acid (48-h LC50, 81.2-121 mg/L) is likely to be due to acid intolerance. Feeding stage tadpoles of B. marinus, X laevis, C. insignifera, H.eyrei, L. dorsalis and L. moorei were exposed to NPE and alcohol alkoxylate in static renewal acute toxicity tests. All species exhibited non-specific narcosis following exposure to both these surfactants. The 48-h EC50 values for NPE ranged between 1.1 mg/L (mild narcosis) and 12.1 mg/L (full narcosis). The 48-h EC50 values for alcohol alkoxylate ranged between 5.3 mg/L (mild narcosis) and 25.4 mg/L (full narcosis). Xenopus laevis was the most sensitive species tested. The sensitivity of the other five species was size dependent with larger species displaying greater tolerance. Replicate acute toxicity tests with B. marinus exposed to NPE at 30 degrees celsius over 96 hours indicated that the narcotic effects were not particularly time dependant. / The mean 24, 48, 72 and 96-h EC50 (mild narcosis) were 3.6, 3.7, 3.5 and 3.5 mg/L respectively. The mean 24, 48, 72, and 96-h EC50 (full narcosis) values were 4.0, 4.1, 4.2 and 4.0 respectively. Acute toxicity tests with B. marinus exposed to NPE at 30 degrees celsius under conditions of low dissolved oxygen (0.8-2.3 mg/L) produced a two to threefold increase in toxicity. The 12-h EC50 values ranged from 1.4 to 2.2 mg/L. The embryotoxicity of NPE was determined in X. laevis, L. adelaidensis and C. insignifera using a Frog Embryo Teratogenesis assay-Xenopus (FETAX). The 96-h LC50, EC50 and MCIG (LOEC) values for X. laevis were 3.9 to 5.4 mg/L, 2.8 to 4.6 mg/L and 1.0 to 3.0 mg/L respectively. The 140-h LC50, ECSO and MCIG values for L. adelaidensis were 9.2 mg/L, 8.8 mg/L and 5.1 to 6.0 ing/L respectively. The 134-h LC50, EC50 and MCIG values for C. insignifera were 6.4 mg/L, 4.5 mg/L and 4.0 mg/L respectively. Teratogenicity indices for the three species ranged between 1.0 and 1.6 indicating either no or low teratogenicity. Xenopus laevis was the more sensitive of the three species and the only species that displayed indisputable terata. The acute toxicity data indicated that the amphibian species tested were of similar sensitivity to fish and some invertebrates. Developmental retardation and oestrogenic effects following exposure to nonylphenol ethoxylate were indicated by sublethal toxicity tests. Crinia insignifera embryos were exposed during early embryogenesis to sublethal concentrations of NPE. / Exposure to NPE did not affect either weight nor size (snout-vent length) at metamorphosis. Exposure to 5.0mg/L NPE resulted in a significant delay in the time required to reach metamorphosis. Also, exposure to 3.0 mg/L NPE for the first 6 days of embryonic development or exposure to 5.0 mg/L NPE from day 2 to day 6 resulted in a statistically significant predominance in the female phenotype amongst metamorphosing froglets. Exposure for the first five days to 1.5 ing/L or 3.0 mg/L NPE had no effect on sex ratio. The results indicated that exposure to NPEs has endocrine disruptive effects in this species and that a narrow window of susceptibility exists for the induction of predominantly female phenotype. This study has also followed the degradation of a mixture of NPE oligomers and the concomitant formation of individual oligomers in static die-away tests with and without illumination in freshwater. Over 33 days in darkness there was a progressive and complete loss of long chain oligomers (NPEO(subscript)8-17), transient increases and subsequent loss of short to medium chain oligomers (NPE0(subscript)4-7), and large persistent increases (approximately 1000%) in short chain oligomers (NPE0(subscript)1-3). In the presence of illumination, biodegradation was retarded and heterotrophic bacterial proliferation was inhibited. After 33 days there was complete loss of long chain oligomers (NPE0(subscript)9-17), incomplete loss of medium chain oligomers (NPE0(subscript)6.8) and increases in short chain oligomers (NPE0(subscript)1-5). / This thesis discusses the importance of persistent metabolites of NPE degradation as it pertains to the habitat, developmental time frame and ecology of amphibians. Degradation of NPE is likely to occur over a time frame that is longer than that required for complete embryogenesis and metamorphosis of many species of amphibians, and may easily encompass those critical stages of development during which oestrogenic metabolites can affect development.
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Structure-Property Relationships of Surfactants at Interfaces and Polyelectrolyte-Surfactant AggregatesKjellin, Mikael January 2002 (has links)
The first part of this thesis is concerned with thestructure-property relationships in nonionic surfactantsystems. The main aim was to investigate how the surfactantstructure influences the adsorption at interfaces andinteractions between surfactant coated interfaces.Particularly, the effect of the structure of the surfactantheadgroups was investigated. These were sugar-based headgroupwith varying size and flexibility and poly(ethylene oxide)based headgroups with or without an additional amide or estergroup. The hydrophobic part of the surfactant consisted mostlyof straight alkyl chains, except for one type of poly(ethyleneoxide) based surfactant with a dehydroabietic hydrophobe. The main technique that was used is the surface forcetechnique, with which the forces acting between two adsorbedsurfactant layers on hydrophilic or hydrophobic surfaces can bemeasured. These forces are important for e.g. the stability ofdispersions. The hydrophilic surfaces employed were glass andmica, whereas the hydrophobic surfaces were silanized glass andhydrophobized mica. The adsorption behavior on hydrophilicsurfaces is highly dependent on the type of headgroup andsurface, whereas similar results were obtained on the two typesof hydrophobic surfaces. To better understand how the surfaceforces are affected by the surfactant structure, measurementsof adsorbed amount and theoretical mean-field latticecalculations were carried out. The results show that the sugarsurfactant layers and poly(ethylene oxide) surfactant layersgive rise to very different surface forces, but that the forcesare more similar within each group. The structure-propertyrelationships for many other physical properties have beenstudied as well. These include equilibrium and dynamicadsorption at the liquid-vapor interface, micelle size, micelledynamics, and wetting. The second part in this thesis is about the aggregationbetween cationic polyelectrolytes and an anionic surfactant.The surface force technique was used to study the adsorption ofa low charged cationic polyelectrolyte on mica, and theaggregation between the adsorbed polyelectrolyte with theanionic surfactant. The aggregation in bulk was studied withturbidimetry, small angle neutron scattering (SANS), and smallangle x-ray scattering (SAXS). An internal hexagonal aggregatestructure was found for some of the bulk aggregates. <b>Keywords:</b>nonionic surfactant, sugar surfactant,poly(ethylene oxide), amide, ester, polyelectrolyte, SDS,hydrophobic surface, glass surface, mica, adsorption,aggregation, micelle size, surface forces, wetting, dynamicsurface tension, NMR, TRFQ, SANS, SAXS, mean-field latticecalculations.
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Nichtionische polyethoxylierte Tenside in methansulfonsauren Zinn- und Zinn-Silber-Elektrolyten / Nonionic polyethoxylated surfactant in methanesulfonic Tin- and Tin-Silver-ElectrolytesWehner, Susanne 24 December 2005 (has links) (PDF)
The investigations are related to the influence of nonionic polyethoxylated surfactant on Tin- and Tin-Silver depositions. Cyclovoltammetry, electrochemical depositions in Hull cell, with quartz crystal microbalance, impedance spectroscopy, X-ray diffraction, REM and others were used as methods of characterization. / Die Untersuchungen befasssen sich mit dem Einfluss von nichtionischen polyethoxylierten Tenside auf die Zinn- und Zinn-Silber-Abscheidung, die durch Zyklovoltammetrie, Abscheidungen in der Hullzelle, mit der elektrochemischen Quarzmikrowaage, der Impedanzspektroskopie, Röntgendiffraktometrie, Rasterelektronenmikroskopie und Tensiometrie charakterisiert wurden.
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Structure-Property Relationships of Surfactants at Interfaces and Polyelectrolyte-Surfactant AggregatesKjellin, Mikael January 2002 (has links)
<p>The first part of this thesis is concerned with thestructure-property relationships in nonionic surfactantsystems. The main aim was to investigate how the surfactantstructure influences the adsorption at interfaces andinteractions between surfactant coated interfaces.Particularly, the effect of the structure of the surfactantheadgroups was investigated. These were sugar-based headgroupwith varying size and flexibility and poly(ethylene oxide)based headgroups with or without an additional amide or estergroup. The hydrophobic part of the surfactant consisted mostlyof straight alkyl chains, except for one type of poly(ethyleneoxide) based surfactant with a dehydroabietic hydrophobe.</p><p>The main technique that was used is the surface forcetechnique, with which the forces acting between two adsorbedsurfactant layers on hydrophilic or hydrophobic surfaces can bemeasured. These forces are important for e.g. the stability ofdispersions. The hydrophilic surfaces employed were glass andmica, whereas the hydrophobic surfaces were silanized glass andhydrophobized mica. The adsorption behavior on hydrophilicsurfaces is highly dependent on the type of headgroup andsurface, whereas similar results were obtained on the two typesof hydrophobic surfaces. To better understand how the surfaceforces are affected by the surfactant structure, measurementsof adsorbed amount and theoretical mean-field latticecalculations were carried out. The results show that the sugarsurfactant layers and poly(ethylene oxide) surfactant layersgive rise to very different surface forces, but that the forcesare more similar within each group. The structure-propertyrelationships for many other physical properties have beenstudied as well. These include equilibrium and dynamicadsorption at the liquid-vapor interface, micelle size, micelledynamics, and wetting.</p><p>The second part in this thesis is about the aggregationbetween cationic polyelectrolytes and an anionic surfactant.The surface force technique was used to study the adsorption ofa low charged cationic polyelectrolyte on mica, and theaggregation between the adsorbed polyelectrolyte with theanionic surfactant. The aggregation in bulk was studied withturbidimetry, small angle neutron scattering (SANS), and smallangle x-ray scattering (SAXS). An internal hexagonal aggregatestructure was found for some of the bulk aggregates.</p><p><b>Keywords:</b>nonionic surfactant, sugar surfactant,poly(ethylene oxide), amide, ester, polyelectrolyte, SDS,hydrophobic surface, glass surface, mica, adsorption,aggregation, micelle size, surface forces, wetting, dynamicsurface tension, NMR, TRFQ, SANS, SAXS, mean-field latticecalculations.</p>
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Untersuchungen zur Tensidverteilung in Reinigungsbädern in der Metall verarbeitenden IndustrieSteiner-Ander, Andrea 02 November 2001 (has links) (PDF)
In dieser Arbeit wird ein industriell genutzter Metallreiniger auf Basis nichtionischer Tenside untersucht. Dabei werden ausschließlich Messmethoden verwendet, die sich auch für eine industrielle Fertigung eignen.
Zu Anfang enthält die Arbeit kurze Abrisse zum gegenwärtigen Kenntnisstand bezüglich der Inhaltstoffe industriell genutzten Reiniger, der Analytik von Tensiden in Reinigern und der Adsorption der Tenside auf Feststoffoberflächen. Im Mittelpunkt der Arbeit steht neben der Charakterisierung und Analyse des Reinigers die quantitative Bestimmung der im Reiniger enthaltenen Tenside in industriellen Reinigungsbädern. Mit Hilfe der Hochleistungsflüssigkeitschromatografie mit einem Verdampfungs - Lichtstreudetektor wird die quantitative Verteilung der Tenside in Reinigungsbädern unter verschiedenen der industriellen Fertigung entsprechenden Bedingungen untersucht. Die Adsorption der im Reiniger enthaltenen Tenside auf der Metalloberfläche unter Fertigungsbedingungen wird mit Fluoreszenzspektroskopie und IR-Spektroskopie quantitativ bestimmt. Im letzten Kapitel wird auf die Umsetzung der gefundenen Ergebnisse in die industrielle Praxis eingegangen.
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Influ?ncia de tensoativos n?o i?nicos na destila??o molecular de petr?leo / Influence of nonionic surfactants in molecular distillation of petroleumLucena, Izabelly Larissa 12 July 2013 (has links)
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Previous issue date: 2013-07-12 / The molecular distillation is show as an alternative for separation and purification of various
kinds of materials. The process is a special case of evaporation at high vacuum, in the order
from 0.001 to 0.0001 mmHg and therefore occurs at relatively lower temperatures, preserves
the material to be purified. In Brazil, molecular distillation is very applied in the separation of
petroleum fractions. However, most studies evaluated the temperature of the evaporator,
condenser temperature and flow such variables of the molecular distillation oil. Then, to
increase the degree of recovery of the fraction of the distillate obtained in the process of the
molecular distillation was evaluated the use nonionic surfactants of the class of nonylphenol
ethoxylate, molecules able to interact in the liquid-liquid and liquid-vapor interface various
systems. In this context, the aim of this work was to verify the influence of commercial
surfactant (Ultranex-18 an Ultranex-18-50) in the molecular distillation of a crude oil. The
physicochemical characterization of the oil was realized and the petroleum shown an API
gravity of 42?, a light oil. Initially, studied the molecular distillation without surfactant using
star design experimental (2H ? ) evaluated two variables (evaporator temperature and
condenser temperature) and answer variable was the percentage in distillate obtained in the
process (D%). The best experimental condition to molecular distillation oil (38% distillate) was
obtained at evaporator and condenser temperatures of 120 ?C and 10 ? C, respectively.
Subsequently, to determine the range of surfactant concentration to be applied in the process,
was determined the critical micellar concentration by the technique of scattering X-ray small
angle (SAXS). The surfactants Ultranex-18 an Ultranex-18-50 shown the critical micelle
concentration in the range of 10-2 mol/L in the hydrocarbons studied. Then, was applied in the
study of distillation a concentration range from 0.01 to 0.15 mol/L of the surfactants (Ultranex-
18 and 50). The use of the nonionic surfactant increased the percentage of hydrocarbons in the
range from 5 to 9 carbons in comparison to the process carried out without surfactant, and in
some experimental conditions the fraction of light compounds in the distilled was over 700%
compared to the conventional process. The study showed that increasing the degree of
ethoxylation of Ultranex18 to Ultranex-50, the compounds in the range of C5 to C9 reduced the
percentage in the distilled, since the increase of the hydrophilic part of the surfactant reduces its
solubility in the oil. Finally, was obtained an increase in the degree of recovery of light
hydrocarbons, comparing processes with and without surfactant, obtained an increase of 10%
and 4% with Ultranex-18 and Ultranex-50, respectively. Thus, it is concluded that the Ultranex-
18 surfactant showed a higher capacity to distillation compared with Ultranex-50 and the
application of surfactant on the molecular distillation from petroleum allowed for a greater
recovery of light compounds in distillate / A destila??o molecular apresenta-se como uma alternativa para separa??o e
purifica??o de diversos tipos de materias. O processo ? um caso especial de evapora??o a alto
v?cuo, na ordem 0,001 a 0,0001 mmHg, e consequentemente, ocorre ? temperaturas
relativamente mais baixas, preservando ao m?ximo o material a ser purificado. No Brasil, a
destila??o molecular ? muito aplicada na separa??o de fra??es de petr?leo. No entanto, boa
parte dos estudos relacionados a destila??o molecular de petr?leo avalia apenas as vari?veis do
processo, tais como: a temperatura do evaporador, temperatura do condensador, vaz?o e etc.
Dessa forma, com o prop?sito de favorecer a destila??o molecular, visando aumentar o grau de
recupera??o da fra??o do destilado obtido no processo, avaliou-se a aplica??o de tensoativos
n?o i?nicos da classe do nonilfenol etoxilado, uma vez que tais mol?culas apresentam a
capacidade de interagir na interface l?quido-l?quido e l?quido-vapor de diversos sistemas.
Portanto, o objetivo deste trabalho foi verificar a influ?ncia de tensoativo comerciais do tipo
Ultranex-18 e Ultranex-50 na destila??o molecular de um petr?leo bruto. Nesse estudo,
realizou-se a caracteriza??o f?sico-qu?mica do petr?leo a ser destilado, determinando-se que o
mesmo apresentava um grau API de 42?, o que confere a amostra a ser destilada uma
caracter?stica de fra??o leve. Na etapa do estudo das destila??es moleculares realizadas sem
tensoativo, aplicou-se um planejamento estrela (2K ? ) com duas vari?veis (temperatura do
evaporador e temperatura do condensador), tendo como resposta a porcentagem de destilado
obtida no processo (%D). Verificou-se que a melhor condi??o experimental para a destila??o
molecular do petr?leo estudado foi aplicando uma temperatura do evaporador de 120?C e do
condensador de 10?C, obtendo-se uma porcentagem de destilado de 38 %. Posteriormente, para
determinar uma faixa de concentra??o de tensoativo a ser aplicado no processo determinou-se a
concentra??o micelar critica aplicando a t?cnica de espalhamento de raio-X de baixo ?ngulo
(SAXS). Atrav?s da t?cnica, constatou-se que para os tensoativos da classe do nonilfenois
etoxilados a concentra??o micelar cr?tica encontra-se na faixa de 10-2 mol/L para os
hidrocarbonetos estudados. A partir dessa constata??o, aplicou-se no estudo das destila??es
com tensoativo (Ultranex-18 e 50) uma faixa de concentra??o entre 0,01 a 0,15 mol/L. Nesta
etapa, verificou-se que a presen?a do tensoativo n?o i?nico aumentou a destila??o de
hidrocarbonetos na faixa de 5 a 9 carbonos em compara??o ao processo realizado sem
tensoativo, e que em alguns casos a fra??o de compostos leves no destilado do processo foi
superior a 700 % em rela??o ao processo convencional. O estudo mostrou que o aumento do
grau de etoxila??o do Ultranex-18 para o Ultranex-50, reduziu a porcentagem de compostos
destilados na faixa de C5 a C9, uma vez que o aumento da parte hidrof?lica do tensoativo reduz
sua solubilidade no petr?leo. Finalmente, verificou-se que o aumento no grau de recupera??o
de hidrocarbonetos leves, comparando os processos com o tensoativo e sem tensoativo, resultou
em um aumento de 10 % para o processo empregando o Ultranex-18 e 4% para o Ultranex-50.
Dessa forma, conclui-se que o Ultranex-18 apresentou maior capacidade de destila??o frente ao
Ultranex-50 e que a aplica??o de tensoativo na destila??o molecular de petr?leo favoreceu o
processo, j? que houve o aumento da concentra??o de compostos leves obtidos
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