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Blends of cardanol-based epoxidized novolac resin and CTBN for application in surface coating : a study on thermal, mechanical, chemical, and morphological characteristics / Ranjana Yadav in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 7, N° 5 (09/2010)
[article]
Titre : Blends of cardanol-based epoxidized novolac resin and CTBN for application in surface coating : a study on thermal, mechanical, chemical, and morphological characteristics Type de document : texte imprimé Auteurs : Ranjana Yadav, Auteur ; Deepak Srivastava, Auteur Année de publication : 2010 Article en page(s) : p. 557-568 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Revêtements Tags : Cardanol 'Résine novolac' 'Carboxyl-terminated butadiene acrylonitrile' (CTBN) 'Analyse calorimétrique différentielle' (DSC) thermogravimétrique' (TGA) Index. décimale : 667.9 Revêtements et enduits Résumé : Blend samples of cardanol-based epoxidized novolac resin and different weight percentages of carboxyl-terminated butadiene acrylonitrile (CTBN) were developed and cured with stoichiometric amounts of aliphatic amine. The formation of various products during the curing of blend samples has been studied by Fourier-transform infrared spectroscopy. The dynamic differential scanning calorimeter scans showed that the pure epoxies and their blend samples with CTBN cured in the temperature range of 100–150°C. The blend sample containing 15 wt% CTBN showed the least cure time (at 120°C) among all other blend samples. Upon evaluation, it was found that blend samples exhibit better properties compared to pure epoxy resin in terms of increase in impact strength and elongation-at-break of the casting and gloss, scratch hardness, adhesion, and flexibility of the film. The improvement in these properties indicates that the rubber modified resin would be more durable than the epoxy based on cardanol. Chemical and morphological properties of the formulated resins were also determined. The thermal stability of the blend samples containing 15 wt% CTBN in epoxy resin was the highest among all other prepared systems. The blend morphology, studied by scanning electron microscope, showed the presence of precipitated discrete rubber particles, which dispersed throughout the epoxy matrix—i.e., they revealed the presence of two-phase morphological features. DOI : 10.1007/s11998-009-9235-8 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-009-9235-8.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9911
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 7, N° 5 (09/2010) . - p. 557-568[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 012448 - Périodique Bibliothèque principale Documentaires Disponible Environmentally preferred coatings from modified cardanol-based epoxidized novolac resin / Ranjana Yadav in PAINTINDIA, Vol. LVIII, N° 6 (06/2008)
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Titre : Environmentally preferred coatings from modified cardanol-based epoxidized novolac resin Type de document : texte imprimé Auteurs : Ranjana Yadav, Auteur ; Deepak Srivastava, Auteur Année de publication : 2008 Article en page(s) : p. 85-100 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cardanol
Chromatographie sur gel
Copolymère carboxyle terminé de Butadiène-acrylonitrile
Copolymère carboxyle terminé liquide de butadiène
Epoxydes
Formaldéhyde
Fourier, Spectroscopie infrarouge à transformée de
Ressources renouvelables
RevêtementsIndex. décimale : 667.9 Revêtements et enduits Résumé : Cardanol-based epoxidized novolac resin was modified with different weight ratios of liquid rubbers, viz. carboxyl-terminated polybutadiene (CTPB) and carboxyl-terminated butadiene - acrylonitrile copolymer (CTBN) for its use as environment friendly coating materials. The cardanol-based epoxy resin was synthesized from novolac resin, prepared from cardanol (C) and formaldehyde (F) having C/F molar ratio equals 1:0.6. A tricarboxylic acid such as citric acid was used as a catalyst for the system. The novolac resin was epoxidized with molar excess of epichlorohydrin at 120°C in basic medium. The epoxidized novolac resins were, separately, blended with different weight ratios of different carboxyl-terminated liquid rubbers and ranging between 0-25 w % with an interval of 5 wt%. All the blends were cured at 120°C with stiochiometric amount ofpolyamine. The formation of various products during the synthesis of cardanol-based novolac resin, epoxidized novolac resin and blending of epoxidized novolac resin with different liquid rubber have been studied by Fourier-transform infra-red (FTIR) spectroscopic analysis. The molecular weights of the prepared novolac and their epoxidized novolac resins were determined by gel permeation chromatographic (GPC) analysis. These blend samples were also found to be most thermally stable systems. Note de contenu : EXPERIMENTAL : Materials - Synthesis of cardanol based novolac-type phenolic resin - Preparation of blends of epoxidized novolac resin and different carboxyl-terminated liquid rubbers - Characterization
RESULTS AND DISCUSSION : Synthesis of cardanol-formaldehyde novolac type phenolic resin - FTIR and GPC of cardanol-formaldehyde resin - Epoxidation of novolac prepolymer - FTIR analysis of uncured and cured samples - Effect of CTPB and CTBN on cure time of blend samples - Morphological properties - Chemical resistancePermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12115
in PAINTINDIA > Vol. LVIII, N° 6 (06/2008) . - p. 85-100[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 010765 - Périodique Bibliothèque principale Documentaires Disponible Studies on epoxy resin curatives and their applications / Garima Tripathi in PAINTINDIA, Vol. LVII, N° 5 (05/2007)
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Titre : Studies on epoxy resin curatives and their applications Type de document : texte imprimé Auteurs : Garima Tripathi, Auteur ; Ranjana Yadav, Auteur ; Deepak Srivastava, Auteur Année de publication : 2007 Article en page(s) : p. 101-107 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Epoxydes
Réticulants
Réticulation (polymérisation)
Revêtements:PeintureIndex. décimale : 667.9 Revêtements et enduits Résumé : The curing process is a chemical reaction in which the epoxide groups in epoxy resin reacts with such a curing agent (hardener) to form a highly cross linked, three- dimensional network. To convert epoxy resins into a hard, infusible and rigid material, it is necessary to cure the resin with hardener. Epoxy resins cure quickly and easily at partially any temperature from ambient-150°C depending on the choice of curing agent. A wide variety of curing agents for epoxy resins are available depending upon the process and properties required. The commonly used curing agents for epoxies include amines, polyamides, phenolic resins., anhydrides etc The cure kinetics and the Tg of the cured system are dependent on the molecular structure of the hardener. When selecting resin-curative combination the applications or end use defines the resin characteristics that must be built into a particular system. The materials have been separated into the general categories of room-temperature cure, room or elevated temperature elevated cure and miscellaneous curatives. In some cases a single curative or class of curatives may fit in more than one of these categories.The present article deals with the recent development, properties and modified applications of epoxy curatives. Note de contenu : - Epoxy curatives
- Room temperature curing agents
- Selection factor
- Room or elevated temperature curing agents
- Elevated temperature curatives
- Miscellaneous uses
- Relationship between cured epoxy resin structure and propertiesPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11486
in PAINTINDIA > Vol. LVII, N° 5 (05/2007) . - p. 101-107[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 008394 - Périodique Bibliothèque principale Documentaires Disponible Studies on the blends of epoxy and different liquid rubber / Ranjana Yadav in PAINTINDIA, Vol. LIX, N° 4 (04/2009)
[article]
Titre : Studies on the blends of epoxy and different liquid rubber Type de document : texte imprimé Auteurs : Ranjana Yadav, Auteur ; Deepak Srivastava, Auteur Année de publication : 2009 Article en page(s) : p. 65-86 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Alliages polymères
Caoutchouc
EpoxydesIndex. décimale : 667.9 Revêtements et enduits Résumé : Epoxy resins, either glycidyl epoxy or non-glydidyl epoxy resins, reacted with a large number of chemical species called curatives or hardeners. Optimum performance properties can be obtained by cross-linking the epoxy resins into a three dimensional and infusible network. The choice of curing agent depends on processing method, curing conditions, i.e., curing temperature and time,physical and chemical properties desired, toxicological and environmental limitations and cost.
But, like other thermosetting resins, the brittleness of epoxy resin is a major deficiency in many applications. To overcome this deficiency of epoxy resins, many attempts have been made to blend them with reactive liquid rubbers such as carboxyl and amine terminated butadiene acrylonitrile rubber (CTBN and ATBN). The properties of epoxy/CTBN or epoxy/ATBN systems, especially their mechanical properties, have been intensively studied, and results have proved that. With an appropriate weight of rubber, the rubber modified resins have strongly improved toughness. In this way, carboxyl-terminated copolymer of butadiene and acrylonitrile (CTBN) has been used by various workers with diglycidyl ether bidphenol A (DGEBA) epoxy resins.
Blend samples containing 0-25 wt% CTBN were prepared according to the procedure simular to that adopted by ting. The calculated quantity of epoxy resin wss, firstly, stirred at 120°C for 1 h to entrap all air bubbles from the resin, the calculated quantity of polyamine was added and stirred to get a clear homogeneous mixture.Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=6827
in PAINTINDIA > Vol. LIX, N° 4 (04/2009) . - p. 65-86[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 011487 - Périodique Bibliothèque principale Documentaires Disponible Studies on the extraction, modification and applications of CNSL/cardanol based epoxy resin / Ranjana Yadav in PAINTINDIA, Vol. LIX, N° 3 (03/2009)
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Titre : Studies on the extraction, modification and applications of CNSL/cardanol based epoxy resin Type de document : texte imprimé Auteurs : Ranjana Yadav, Auteur ; Deepak Srivastava, Auteur Année de publication : 2009 Article en page(s) : p. 69-104 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cardanol
EpoxydesTags : 'Cashew nut shell liquid' (CNSL) Extraction Modification Application 'Résine époxyde' Index. décimale : 667.9 Revêtements et enduits Résumé : The use of fossil carbon-based monomers in the manufacture of polymers is going down because of their spiraling prices and high rate of depletion of the stocks. This necesitated a look at the renewable natural resources that can serve as alternative feddstock of monomers for the polymer industry. In this respect, cashew nut shell liquid (CNSL), an abundant agricultural byproduct, holds considerable promise as a source of unsaturated phenol, an excellent monomer for polymer production. Cardanol, a major constituent of CNSL, can be used for the preparation of cardanol-based novolac/resoleresins. The cardanol-based novolac resins can further be epoxidezed with epichlorohydrin resulting in epoxidized novolac resins. therefore, in the first part of the paper, extraction of cardanol from CNSL, development of novolac resins and epoxidized novolac resin sfrom cardanol or modified products from CNSL or cardanol and various application sectors which utilize modified cardanol-based products is reviewed. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=6887
in PAINTINDIA > Vol. LIX, N° 3 (03/2009) . - p. 69-104[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 011333 - Périodique Bibliothèque principale Documentaires Disponible Toughening of cardanol based epoxidized novolac resin with acrylonitrile butadiene liquid ruber / Ranjana Yadav in PAINTINDIA, Vol. LXII, N° 12 (12/2012)
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