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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Résines alkydes biosourcées uréthanisées sans isocyanate par réticulation non-oxydative / Biobased non-isocyanate urethanized alkyd resins with non-oxidative crosslinking mechanism

Sonnati, Matthieu 30 September 2013 (has links)
Les résines alkydes sont les principaux liants des peintures et vernis modernes. Ces polymères sont obtenus par polycondensation de polyacides, polyols, acides gras et monoacides. L’engouement croissant pour le développement durable pousse à la transition de produits pétrosourcés vers des produits biosourcés, à coûts et performances similaires. Pour les alkydes qui utilisent déjà en partie des matières premières renouvelables (acides gras, polyols), le challenge consiste à substituer les composants pétrosourcés restants tels que les dérivés phtaliques et benzoïques. Après un état de l’art sur les alkydes, nous avons étudié les implications liées à la substitution de ces dérivés. Plusieurs résines alkydes biosourcées furent synthétisées et caractérisées par des mesures physico-chimiques (SEC, DSC, rhéomètre). Les peintures alkydes conventionnelles sèchent chimiquement par un mécanisme oxydatif qui requiert des sels de cobalt pour advenir en moins de 6 h. A cause de leur toxicité, ces sels sont sous pression par REACH. Nous avons proposé un mécanisme alternatif de réticulation non-oxydatif basé sur la réaction entre les groupes 2-oxo-1,3-dioxolane (ODO) et les amines primaires. La réaction modèle entre le carbonate de glycérol et l’éthylenediamine nous a permis de comprendre la viabilité de ce mécanisme de réticulation. La création de groupes ODO a d’abord été étudiée sur des huiles végétales afin de déterminer les conditions optimales et confirmer les possibles réactions d’oligomérisation. Des alkydes portant ces groupes ODO ont pu être synthétisées et caractérisées, puis converties en résines alkydes uréthanisées sans isocyanate par réaction avec des diamines. / Alkyd resins are the major binders used in surface coatings today. They are obtained by polycondensation of polybasic acids, polyols, fatty acids and monobasic acids. The raising sustainability awareness is pressuring for the transition from petrobased to biobased products with equivalent costs and performances. While conventional alkyd resins have high content in renewable raw materials such as fatty acids and polyols, replacement of petrobased raw materials such as phthalate and benzoic derivatives remained a challenge. After reviewing the current state-of-the-art regarding conventional alkyd resins, we focused on understanding the specific issues related to the synthesis of biobased alkyd resins. Several biobased alkyd resins were synthesized and characterized using techniques such as SEC, DSC and rheometer. Conventional alkyd paints chemically dry through an oxidative mechanism, which requires cobalt salts to occur in less than 6 h. These salts are under the scope of REACH because of their toxicity. As a possible alternative, we proposed a non-oxidative crosslinking mechanism based on the reaction of 2-oxo-1,3-dioxolane (ODO) groups and primary amines. This crosslinking mechanism was first studied with the model reaction between glycerol carbonate and ethylenediamine. The functionalization of ODO groups on vegetable oils was then studied as model molecule of alkyd resins, enabling the determination of optimal reaction conditions and that oligomerization occurs as a side reaction. Alkyd resins bearing ODO groups were then synthesized and characterized, then converted into non-isocyanate urethanized alkyd resins by reaction with diamines.
12

Synthesis And Characterization Of Solvent Free Alkyd Resin With Hyperbranched Melamine Core

Keskin, Nagehan 01 February 2011 (has links) (PDF)
The use of volatile organic compounds (VOC) in coating materials has adverse effects on both human health and the environment. Due to concern over these problems, coating industry has attempted to decrease the solvent contents of coating materials for the last three decades by developing water dispersed and powder paints. A recently developed method to make solvent free paint is to use highly branched polymers in high solid alkyd resins. Highly branched polymers help to achieve resins with viscosity much lower than its linear counterparts. In this study, a new alkyd based resin was formulated using long oil alkyd and melamine based hyperbranched polymer having 24 functional groups on its structure. The long oil alkyd was synthesized by using an oil mixture (40% linseed + 60% sunflower). Melamine was preferred as core molecule due to its excellent properties such as greater hardness, alkali and solvent resistance with thermal stability. The resin produced has low viscosity because its hyperbranched structure / therefore, it needs no solvent for its application. The chemical characterization of the resins with different compositions was performed using Fourier Transform Infrared Spectroscopy and thermal properties were determined by Differential Scanning Calorimetry. Physical and mechanical tests were conducted to determine hardness, flexibility, impact resistance, abrasion resistance, adhesion power, and gloss property of the samples. The viscosity of the resins decreased from 148 Pa.s to 8.84 Pa.s as the hyperbranched polymer to long oil alkyd ratio was increased from 1:3 to 1:24. On the other hand, the hardness values of the resins decreased from 198 Persoz to 43 Persoz. All resins showed excellent flexibility, formability, adhesion, and gloss.
13

Granvirkes permeabilitet beroende av dess fysikaliska utformning och applicerat färgsystem

Johansson, Amanda January 2015 (has links)
Densitetsmätningar och permeabilitetstest enligt EN 927-5 har utförts för att studera huruvida granvirkes fysikaliska egenskaper i kombination med applicerat färgsystem påverkar permeabiliteten. De egenskaper som studerats är frod- och senvuxenhet, splint- och kärnved samt densitet. Aktuella färgsystem som studerats är alkyd, akrylat och linolja, vilka jämförts med omålad referens. Studien påvisar inget samband mellan virkets densitet och permeabilitet, bestruket eller ej. Det som istället tycks påverka vattenabsorptionen är närvaro av splint-/kärnved samt frod-/senvuxenhet. Senvuxen kärnved var den bestrukna vedtyp som absorberade mest vatten gällande samtliga färgsystem. Vedtyp som hade lägst vattenabsorption varierade dock. Linolja var generellt det färgsystem som gav lägst permeabilitet, främst på frodvuxen kärnved. Denna kombination hade lägst absorption genom hela försöket.
14

Vliv esterů kyseliny glutarové na vybrané akrylátové a alkydové nátěrové systémy / The influence of esters of glutaric acid to the selected acrylic and alkyd coating systems

Holubová, Anna January 2017 (has links)
The aim of this diploma thesis is a study and description of a mutual interaction of solvents belonging to the green solvents group, specifically glutaric acid esters and selected acrylic and alkyd coating systems. In the experimental part of this thesis there is a study of a resistance of the coating systems to solvents by the spotting method, which is subsequently then combined with an adhesion experiment of the coating film by the cross-cut test. Those experiments are made according to matching methods in valid version.
15

Modification of Tung Oil for Bio-Based Coating

Thanamongkollit, Narin 02 September 2008 (has links)
No description available.
16

Mise en émulsion sans tensioactif de résines alkydes et formulation de peintures biosourcées / Free surfactants alkyd resin emulsification and biobased paints formulations

Romand, Alison 21 January 2016 (has links)
Les peintures sont omniprésentes dans nos civilisations modernes et décorent presque tous les supports et ce dans des domaines très variés. L'utilisation massive des peintures pose cependant des problèmes environnementaux et de santé publique, de par la présence de solvants qui, lors du séchage, s'évaporent et émettent des composés organiques volatiles (COV) néfastes pour l'environnement et l'homme. Une démarche européenne et mondiale de réduction d'émission des COV est donc en cours depuis quelques années. De plus, l'engouement croissant pour le développement durable pousse à la transition de produits pétrosourcés vers des produits biosourcés, à coûts et performances similaires. Les résines alkydes en émulsions, développées au début du XXème siècle, constituent une alternative de choix car émettant une quantité limitée de COV et obtenues par polycondensation de matières premières renouvelables. Après un état de l'art sur le contexte des peintures actuelles et la composition d'une peinture alkyde en émulsion, leurs propriétés physiques et chimiques ont été étudiées. Après ce travail de formulation, deux additifs ont été synthétisés afin d'augmenter le taux de biosourcé des peintures alkydes en émulsion : un épaississant et un agent dispersant. De par la présence de surfactants, les formules de peintures alkydes en émulsion sont pour l'heure moins compétitives que les peintures alkydes en phase solvant. En conséquence, la première émulsion alkyde sans tensioactif a été développée et ses performances évaluées en peinture / Paints and coatings occupy a prominent place in the cultural history of mankind. People have always been fascinated by colors and used paints to decorate and beautify themselves and their environment. Nevertheless, these products bring a lot of problems. For instance, some paints still contain organic solvents, which have negative impacts on the environment and human health. Due to environmental legislations and the need to reduce VOCs emission (volatile organic compounds), water-based paints have attracted a lot of interest. Moreover, the raising sustainability awareness is a driving force for the transition from petrobased to biobased products with equivalent costs and performances. In this context, alkyd resin emulsion, introduced in the 1990s, still continue to be the most widely used binder, because they have low VOCs level and are synthesized by polycondensation reactions of renewable raw materials. After reviewing the current state of the art regarding the alkyd paint emulsion, their physical and chemical properties were studied. Two additives, respectively a rheology modifier and a dispersing agent, were also synthesized, in order to increase the biobased content of alkyd paint emulsion Due to the presence of wetting agent, alkyd emulsion paints are still less competitive than solvent-borne alkyd paints. The first surfactant free alkyd emulsion was consequently developed and its film properties characterized in paint formulation
17

Synthesis of polymer-polymer hybrids by miniemulsion polymerisation and characterisation of hybrid latex / Synthèse d'hybrides polymère-polymère par la polymérisation en miniémulsion et la caractérisation des latex hybrides

Udagama, Ravindra 05 October 2009 (has links)
Les objectifs du travail présenté ici sont de comprendre les procédés de formulation des gouttelettes et des particules afin de faire des hybrides polymère-polymère de qualité en dispersions aqueuses et d’utiliser notre compréhension fondamentale de ces procédés pour : 1. Augmenter le taux de conversion de(s) monomère(s) autant que possible. 2. Comprendre l’impact de ces procédés sur les propriétés des films hybrides. Des cas particuliers ont été étudiés dans des conditions commercialement viables (taux de solide de 50% en masse) basés sur deux systèmes appelés alkyde-acryliques et polyuréthane-acrylique. La préparation des miniémulsions, la polymérisation en miniémulsion et la caractérisation des latex hybrides, l’incorporation chimique d’alkyde et de polyuréthane dans les monomères acryliques ont été étudiés en détails. Nous sommes parvenus à synthétiser et caractériser des latex hybrides avec de haut taux de solides (50% en masse) composés de particules de 100nm de diamètre utilisables dans des applications de revêtement et d’adhésifs / The objectives of work presented in this thesis are to understand droplet and particle formulation processes in order to make useful polymer-polymer hybrids in aqueous dispersions and use our fundamental understanding of these processes to: 1. Improve monomer conversion as much as possible. 2. Understand impact of these processes on hybrid film properties. Specific case studies of interest under commercially feasible conditions (i.e. solids content of 50wt %) were done based on two systems namely alkyd-acrylic and polyurethane-acrylic. Miniemulsification, miniemulsion polymerisation and characterisation of hybrid latex, chemical incorporation of alkyd and polyurethane to acrylic monomers were studied in detail. We have been able to successfully synthesise and characterise hybrid latex of about 100nm in particle diameter and high solids content (50wt %) to be used in coating and adhesive applications
18

Síntese e caracterização de polímero híbrido acrílico-alquídico produzido por polimerização em miniemulsão. / Synthesis and characterization of alkyd-acrylic hybrid polymer produced by miniemulsion polymerization.

Badin, Caroline 06 February 2015 (has links)
Polímeros híbridos são caracterizados por conter numa mesma partícula dois tipos diferentes de polímero, normalmente incompatíveis e ligados por ligações covalentes. Neste trabalho, a síntese de um polímero híbrido acrílico-alquídico pelo processo de miniemulsão foi investigada. Com o objetivo de compreender como diferentes variáveis na fórmula afetam as características físico-químicas finais do látex, um planejamento experimental foi desenhado com o auxílio do software DX9 e os resultados analisados por modelos empíricos de superfície de resposta. Os fatores variados (variáveis independentes) foram: quantidade de co-estabilizante, surfactante e iniciador. Cada um dos fatores contribuiu para a alteração de pelo menos uma característica avaliada, e a sinergia entre eles afeta diretamente o teor de RDG, resposta indicativa do grau de grafitização entre as espécies. O coestabilizante contribuiu para o aumento do diâmetro médio de gotas e da polidispersidade de tamanho de partículas, enquanto reduziu a dureza do filme. A concentração de surfactante alterou o número de partículas por litro, reduzindo o diâmetro médio de partículas e aumentando a polidispersidade. O iniciador aumentou a conversão monomérica. Todas as dispersões de polímero híbrido produzidas apresentaram redução do tamanho médio de gotas para partículas, indicando evidência de nucleação secundária. As avaliações por microscopia eletrônica de transmissão (TEM) e microscopia de força atômica (AFM) mostraram que a morfologia obtida é do tipo núcleo-casca. / Hybrid polymers are defined by the presence of two or more different kinds of polymers in the same particle, typically incompatible and linked by covalent bonds. In this work, the synthesis of an alkyd-acrylic hybrid polymer produced by miniemulsion polymerization has been investigated. With the goal of understanding how different variables in the recipe affect the final characteristics of the latex, a design of experiment was planned using DX9 software and the results were analyzed by response surface methodology. The factors studied (independent variables) were: amount of co-stabilizer, surfactant and initiator. Each of these factors contributed to change at least one of the evaluated characteristics, and the synergy between them directly affects the RDG content, response of the polymer degree of grafting. Costabilizer contributed to increase the average droplets diameter and polydispersity of particle size, while reducing the film hardness. The amount of surfactant changed the number of particles, reducing the average particle size and increasing polydispersity. Initiator increased the monomer conversion. All hybrids dispersions presented a decrease in the droplet size to particle size, indicating evidence of secondary nucleation. Core-shell morphology was observed through transmission electron microscopy (TEM) and atomic force microscopy (AFM).
19

Projektovanje strukture premaza na bazi klasičnih i hiperrazgranatih alkidnih smola / Projection of structure of coatings based onconventional and hyperbranched alkyd resins

Jovičić Mirjana 22 July 2011 (has links)
<p>Sintetisane su klasične alkidne smole polazeći od ricinolne kiseline, anhidrida ftalne<br />kiseline i tri poliola (glicerina, trimetilolpropana i etoksilovanog pentaeritritola), kao i<br />hiperrazgranati alkidi na osnovu ditrimetilolpropana, dimetilolpropionske kiseline i<br />ricinolne kiseline. Smole su karakterisane određivanjem hidroksilnog i kiselinskog broja,<br />viskoznosti, srednjih molskih masa i njihove raspodele. Struktura sintetisanih smola je<br />potvrđena infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR).<br />Sintetisani alkidi imaju veliki sadržaj hidroksilnih grupa, a mali kiselinski broj. Prisustvo<br />hidroksilnih grupa, kao krajnjih funkcionalnih grupa, omogućuje modifikaciju alkidnih<br />smola i dobijanje materijala različitih svojstava. Sintetisani alkidi su umrežavani sa<br />triizobutoksimetil i heksametoksimetil melaminskom smolom u cilju dobijanja umreženog materijala željene strukture i svojstava za primenu u premazima. Umrežavanje sme&scaron;a smola praćeno je FTIR spektroskopijom, dinamičko skanirajućom kalorimetrijom (DSC), reometrijom, kao i određivanjem sadržaja gela. Ispitivana su toplotna svojstva, dinamičkomehaničko pona&scaron;anje, fizičko-mehaničke karakteristike i hemijska otpornost filmova premaza. Umrežavanje sme&scaron;a smola teče uglavnom preko hidroksilnih i karboksilnih grupa alkida sa izobutoksimetil i metoksimetil grupama u melaminskim smolama. Sintetisane klasične alkidne smole u sme&scaron;i sa melaminskim smolama umrežavaju u temperaturnom opsegu od 90 do 170&nbsp;<sup>0</sup>C, a hiperrazgranati alkidi od 80 do 170&nbsp;<sup>0</sup>C, &scaron;to su uobičajene temperature u tehnologiji lakova koji umrežavaju &ldquo;pečenjem&ldquo;. Umreženi filmovi premaza su toplotno veoma stabilni, budući da početak razgradnje premaza započinje na temperaturama od 281 do 330 <sup>0</sup>C. Potvrđeno je da postoji linearna zavisnost između modula izgubljene energije na 25 <sup>0</sup>C, koji je mera viskoznog odgovora materijala, i tvrdoće premaza određene metodom klatna. Svi projektovani premazi, bez obzira na nesavr&scaron;enost nastale polimerne mreže, su pokazali zadovoljavajuća svojstva. Najbolja svojstva od klasičnih alkidnih premaza ima onaj na osnovu sme&scaron;e alkida sa etoksilovanim pentaeritritolom i heksametoksimetil melaminske smole. Kori&scaron;ćenje hiperrazgranatih alkidnih smola kao veziva u ekolo&scaron;ki prihvatljivim premazima ima prednost zbog manjeg sadržaja organskih rastvarača i manje viskoznosti u odnosu na klasične smole. Pretpostavljeno je da bi sme&scaron;e sintetisanih klasičnih i hiperrazgranatih alkida sa melaminskim smolama (maseni odnos 70:30) bile pogodne za primenu u industriji boja i lakova. Potvrđeno je da su sistemi alkid/melaminska smola veoma složeni. Dobijeni rezultati omogućuju da se objasni uticaj građe prekursora na strukturu nastale polimerne mreže, a time i na svojstva premaza.</p> / <p>Conventional alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol), as well as hyperbranched alkyds based on ditrimethylolpropane, dimethylol propionic acid and ricinoleic acid were synthesized. Prepared alkyds were characterized by the determination of hydroxyl and acid numbers, viscosity, average molecular masses and molecular masses distribution. The structure of synthesized resins is confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Obtained alkyd resins have high content of hydroxyl groups and low acid number. The presence of hydroxyl groups as functional end groups opens up a high potential for further chemical modifications and for obtaining materials with different properties. Synthesized alkyds were cured by triisobutoxymethyl- and hexamethoxymethyl melamine resins, in order to obtain crosslinked material with desired structure and properties for coating applications. Curing of the resin mixtures were examined by FTIR spectroscopy, dynamic scanning calorimety (DSC), rheometry and by the determination of gel content. Thermal properties, dynamic mechanical behavior, physico-mechanical characteristics and chemical resistance of coated films were determined. Curing of the resin mixtures proceeds via the reactions between hydroxyl and carboxyl groups of alkyds with isobutoxymethyl and metoxymethyl groups in melamine resins. Synthesized alkyd/melamine resin mixtures became cured in the temperature range from 80 to 170 0C, which is the usual temperature range employed in the baking enamel technology. Cured films are thermally very stable since the onset of films degradation starts at high temperatures (from 281 to 330 0C). It is confirmed that there is a linear dependence between the loss modulus at 25 0C, which is the measure of the material viscosity response, and the coating hardness determined by pendulum method. All projected coatings, despite of defects in the resulting polymer networks, show satisfying properties. Among the conventional systems coating based on mixture of alkyd with ethoxylated pentaerythritol and hexamethoxymethyl melamine resin show the best properties. Application of hyperbranched alkyd resins, as binders in environment friendly coatings has an advantage due to less content of organic solvent and lower viscosity, compared to conventional alkyd resins. It is supposed that the combination of synthesized conventional and hyperbranched alkyds with melamine resins (weight ratio of 70:30 based on dried mass) could be employed as new materials for the industrial preparation of baking enamels. It is confirmed that alkyd/melamine resin systems are very complex. Results obtained enable to explain the effect of precursor type on the structure of resulting polymer network, and thus, on the coating properties.</p>
20

Synthesis of polymer-polymer hybrids by miniemulsion polymerisation and characterisation of hybrid latex

Udagama, Ravindra 05 October 2009 (has links) (PDF)
The objectives of work presented in this thesis are to understand droplet and particle formulation processes in order to make useful polymer-polymer hybrids in aqueous dispersions and use our fundamental understanding of these processes to: 1. Improve monomer conversion as much as possible. 2. Understand impact of these processes on hybrid film properties. Specific case studies of interest under commercially feasible conditions (i.e. solids content of 50wt %) were done based on two systems namely alkyd-acrylic and polyurethane-acrylic. Miniemulsification, miniemulsion polymerisation and characterisation of hybrid latex, chemical incorporation of alkyd and polyurethane to acrylic monomers were studied in detail. We have been able to successfully synthesise and characterise hybrid latex of about 100nm in particle diameter and high solids content (50wt %) to be used in coating and adhesive applications

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