Cardanol – an eco-friendly isocyanate blocking agent / Yun mi Kim in COATINGS WORLD, Vol. 24, N° 2 (02/2019)  

[article]  inCOATINGS WORLD > Vol. 24, N° 2 (02/2019) Titre : Cardanol – an eco-friendly isocyanate blocking agent : Deblocking performances and methods to optimize deblocking temperature Type de document : texte imprimé Auteurs : Yun mi Kim, Auteur ; Anbu Natesh, Auteur ; Pietro Campaner, Auteur Année de publication : 2019 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cardanol Catalyseurs Isocyanates Polymères -- Détérioration Polypropylène glycol Polyuréthanes Prépolymères Un pré-polymère ou prépolymère est un oligomère ou un polymère présentant des groupes réactifs qui lui permettent de participer à une polymérisation ultérieure et d’incorporer ainsi plusieurs unités monomères dans au moins une chaîne de la macromolécule finale. Les pré-polymères peuvent être di-fonctionnels (c'est le cas des pré-polymères téléchéliques) ou plurifonctionnels. Dans ce dernier cas, ils sont utilisés pour la fabrication de polymères thermodurcissables par réticulation. Structure chimique Index. décimale : 667.9 Revêtements et enduits Résumé : Cardanol, a well-known non-edible natural oil derived from the cashew nut shell liquid, is a USDA certified bio-based product. Once used as a very high purity grade (NX-2026,TM 3-pentadeca-dienyl-phenol) in PU prepolymers, this substance has demonstrated various benefits including favorable deblocking conditions, lower viscosity, and excellent storage stability compared to commonly used phenolic compounds. One of the most known deblocking methods involves exposure to elevated temperatures, i.e., 150 °C – 200 °C. However, not all substrates (e.g., plastics) and applications can accommodate such high temperatures for deblocking, thus, the possibility to optimize deblocking conditions can be a valuable tool to further expand the applicability of 3-pentadeca-dienyl-phenol as a label-friendly polyurethane prepolymers’ blocking agent. In this study, we present different approaches to control NX-2026 deblocking conditions. First, 3-pentadeca-dienyl-phenol blocked prepolymers were prepared starting from different diols (e.g., PPG, polyester, CNSL-based) as well as aromatic (MDI, TDI) and aliphatic (HDI, IPDI) isocyanates. These were subsequently characterized for their deblocking temperatures and used as model substrates for the study. Key factors for controlling deblocking conditions such as catalysts, deblocking agents (amines, polyols), and solvents were investigated. Note de contenu : - Fig. 1 : Anacardium Occidentale fruit (left) and schematic process for cardanol recovery - Fig. 2 : Examples of cardanol’s potential functionalization - Fig. 3 : NX-2026 (3-pentadeca-dienyl-phenol) chemical structure - Fig. 4 : Possible reactions of blocked isocyanates - Fig. 5 : Proposed mechanism for PU depolymerization catalyzed by dibutyltin dilaurate - Fig. 6 : Effect of chain extender (amine) on deblocking temperatures of NX-2026TM-blocked prepolymers - Table 1 : Appearance and deblocking temperatures of blocked isocyanates - Table 2 : Deblocking temperature and time for blocked PPG prepolymers - Table 3 : Typical average deblocking temperatures for different PU substrates - Table 4 : Effect of catalysts on deblocking temperatures of NX-2026-isocyanate adducts - Table 5 : Effect of catalysts on deblocking temperatures of NX-2026-blocked prepolymers - Table 6 : Effect of chain extender (polyol) and catalysts on deblocking temperatures of NX-2026-blocked prepolymers - Table 7 : Use of catalysts to tune deblocking temperatures on other types of NX-2026-blocked prepolymers - Table 8 : MW variation (%, determined by GPC) of NX-2026-blocked PPG prepolymers in presence of very effective deblocking catalysts Tegoamin 33 and DABCO K15 after storage at 50 °C for 10 days - Table 9 : MW variation (determined by GPC) of NX-2026-blocked PPG prepolymers in presence of a chain extender (propoxylated sorbitol polyol) and of very effective deblocking catalysts Tegoamin 33 and DABCO K15 after storage at 50 °C for 10 days - Table 10 : Effect of chain extender (polyol) and alternative catalysts on deblocking temperatures of NX-2026-blocked prepolymers - Table 11 : MW variation (determined by GPC) of NX-2026-blocked PPG prepolymers in presence of a chain extender (propoxylated sorbitol polyol) and of alternative catalysts after storage at 50 °C for 10 days - Table 12 : Effect of chain extender (amine) and catalysts on deblocking temperatures of NX-2026-blocked prepolymers En ligne : https://www.coatingsworld.com/issues/2019-02-01/view_technical-papers/cardanol-- [...] Format de la ressource électronique : Html Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32507 [article]

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Characterization of titanium alkoxide sol-gel systems designed for anti-icing coatings : II. mass loss kinetics / Jennifer Ayres in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 4, N° 4 (12/2007)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 4, N° 4 (12/2007) . - p. 473-481 Titre : Characterization of titanium alkoxide sol-gel systems designed for anti-icing coatings : II. mass loss kinetics Type de document : texte imprimé Auteurs : Jennifer Ayres, Auteur ; W. H. Simendinger, Auteur ; C. M. Balik, Auteur Année de publication : 2008 Article en page(s) : p. 473-481 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Alcoxyde de titane Diffusion (physique) Polypropylène glycol Revêtements protecteurs Sol-gel, Procédé Index. décimale : 667.9 Revêtements et enduits Résumé : New coatings have been developed that display resistance to the nucleation and adhesion of ice [Simendinger, WH III, Miller, SD, Anti-icing composition. US Patent #6,702,953 2004]. These coatings contain a titanium alkoxide-based sol-gel system designed to facilitate the slow release of tripropylene glycol (TPG) and glycerol, which depress the freezing point of water. The performance and the lifetime of this coating critically depend on the rate at which TPG and glycerol are released to the coating surface. The kinetics and mechanism of this process are studied in this article. Mass loss measurements are reported for temperatures ranging from 22 to 90°C for both the isolated sol-gel and the coating. Two regions of mass loss are observed: loss of isopropyl alcohol, which begins immediately after the reactants are mixed, and loss of TPG and glycerol, which begins at a later time, extending up to several months at low temperatures. Diffusivities and activation energies for IPA and TPG/ glycerol in the sol-gel are obtained from 22 to 90°C and compared to similar data obtained for an anti-icing coating containing the dispersed sol-gel. The effect of changing the sol-gel reaction conditions on mass loss kinetics is also reported. DOI : 10.1007/s11998-007-9055-7 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-007-9055-7.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3634 [article]

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Deformable liposomes as enhancer of caffeine penetration through human skin in a Franz diffusion cell test / E. Abd J. Gomes in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 43, N° 1 (02/2021)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 43, N° 1 (02/2021) . - p. 1-10 Titre : Deformable liposomes as enhancer of caffeine penetration through human skin in a Franz diffusion cell test Type de document : document électronique Auteurs : E. Abd J. Gomes, Auteur ; C. C. Sales, Auteur ; S. Yousef, Auteur ; F. Forouz, Auteur ; K. C. Telaprolu, Auteur ; M. S. Roberts, Auteur ; J. E. Grice, Auteur ; P. S. Lopes, Auteur ; V. R. Leite-Silva, Auteur ; N. Andréo‐Filho, Auteur Année de publication : 2021 Article en page(s) : p. 1-10 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Caféine Essais (technologie) Formulation (Génie chimique) Liposomes Pénétration (physique) Perméation Polypropylène glycol Index. décimale : 668.5 Parfums et cosmétiques Résumé : - Objective : The permeation of hydrophilic molecules through the skin is still a challenge due to the barrier posed by stratum corneum, the outermost layer of the skin. Liposomes have frequently been used as carriers for different types of drugs and may also function as permeation enhancers. Propylene glycol has also been used as an edge activator in liposomes to increase the permeation. The aim of this work was to prepare liposomes containing an edge activator and loaded with caffeine to evaluate the potential of caffeine reaching the deeper layers in the skin. - Methods : The formulations were prepared by a top-down process using high-pressure homogenization at 200 00 psi for 10 min. They were characterized by size, polydispersity index (PI), zeta potential (ZP), pH, caffeine content and encapsulation efficiency (EE%) on preparation (time zero) and after 30 days. Cytotoxicity of blank and loaded liposomes was assessed by MTT proliferation assay with a normal keratinocyte cell line (HaCaT). In vitro permeation tests were performed with human skin in Franz cells over 24 h, and caffeine concentration was determined in the skin surface, stratum corneum, dermo-epidermal fraction and receptor medium by HPLC. - Results : The caffeine liposomes with (DL-Caf) or without propylene glycol (CL-Caf) showed, respectively, mean size 94.5 and 95.4 nm, PI 0.48 and 0.42, ZP + 1.3 and + 18.1 mV and caffeine content of 78.57 and 80.13%. IC50 values of caffeine in DL-Caf (3.59 v/v %) and CL-Caf (3.65 v/v %) were not significantly different from conventional blank liposome (3.27 v/v %). The DL-Caf formulation presented the best capability to enhance the caffeine permeation through the skin, resulting 1.94-folds higher than caffeine solution. Furthermore, the caffeine flux from DL-Caf was 1.56- and 3.05-folds higher than caffeine solution and CL-Caf, respectively. On the other hand, CL-Caf showed the lowest caffeine penetration revealing the importance of edge activator to aid hydrophilic drug penetration to all skin layers. - Conclusion : The DL-Caf formulation tested was able to improve the permeation of caffeine through the stratum corneum and dermo-epidermal layers, suggesting that this delivery system may be effective for deep skin delivery of hydrophilic drugs. Note de contenu : - MATERIALS AND METHODS : Materials - Preparation of liposomes - Characterization of liposome formulations - Caffeine quantification and encapsulation efficiency (EE%) - Cell culture studies - Treatment solutions - Cytotoxicity assay : MTT test - Caffeine skin permeation studies - Sample analysis - Data analysis and statistics - RESULTS AND DISCUSSION : Characterization of liposomes - Encapsulation Efficiency (EE%) - Cytotoxicity tests - Permeation of Caffeine from Liposomes and Controls - Table 1 : Liposome formulations and controls composition - Table 2 : Characterization of liposomes formulations data. Measurements were done at zero and thirtieth days. All data are results of three analyses (n = 3) - Table 3 : Content of caffeine in liposomes formulation and encapsulation efficiency (EE%) - Table 4 : IC50 values of conventional liposome and caffeine encapsulated on HaCaT cell line - Table 5 : Permeation parameters following 24-h application of caffeine from liposome formulations and controls to full-thickness human skin (mean SD, n = 3) DOI : https://doi.org/10.1111/ics.12659 En ligne : https://drive.google.com/file/d/1xwcDoaHKMJNtr-XBVeV4cz__-o2pSCsZ/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35438 [article]

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Effect of polyether soft segments on structure and properties of waterborne UV-curable polyurethane nanocomposites / Shengwen Zhang in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 12, N° 3 (05/2015)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 12, N° 3 (05/2015) . - p. 563-569 Titre : Effect of polyether soft segments on structure and properties of waterborne UV-curable polyurethane nanocomposites Type de document : texte imprimé Auteurs : Shengwen Zhang, Auteur ; Jianfeng Chen, Auteur ; Dan Han, Auteur ; Yongqi Feng, Auteur ; Chen Shen, Auteur ; Chen Chang, Auteur ; Zhilin Song, Auteur ; Jie Zhao, Auteur Année de publication : 2015 Article en page(s) : p. 563-569 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Emulsions inverses Gel de silice Nanoparticules Oxyde de polyphénylène Polyéthers Polyéthylène glycol Polymères en émulsion Polyoxytétraméthylène glycol Polypropylène glycol Polyuréthanes Index. décimale : 667.9 Revêtements et enduits Résumé : Waterborne UV-curable polyurethane (WUPU)/silica nanocomposites were prepared using three types of polyether (PEO-PPO-PEO, PPG, and PTMG) and aqueous colloidal silica by phase-inversion emulsification. The PEO-PPO-PEO and PPG-WUPU nanocomposite dispersions exhibited smaller particles and higher viscosity than their pure WUPU dispersions, whereas PTMG-WUPU nanocomposite dispersion exhibited larger particles and higher viscosity than its pure WUPU dispersion. The SEM analysis indicated that the continuous silica clusters network was distributed in the PEO-PPO-PEO-WUPU matrix, whereas the separate silica clusters were dispersed in the PPG and PTMG-WUPU matrix, respectively. The DMA analysis demonstrated that a slight narrowing of the peak in tanδ and a shift in T g toward lower temperature were observed for the WUPU nanocomposite films with PEO-PPO-PEO and PPG. Conversely, the PTMG-WUPU nanocomposite film showed the insensitivity of the soft segment glass transition (T g) peak positions, supporting preferential attraction of the silica nanoparticles to the highly polar hard segments. The WUPU nanocomposite films showed increased storage modulus, Young’ modulus, and tensile strength. However, for toughness, only the PTMG-WUPU nanocomposite film exhibited great improvement when compared to its pure film due to the silica nanoparticles preferential, but not exclusive, interaction with the hard segment of WUPU. Note de contenu : - EXPERIMENTAL : Materials - Preparation of WUPU/silica nanocomposite dispersions - Testing methods - RESULTS AND DISCUSSION : Colloidal properties of WUPU/silica nanocomposite dispersions - Silica nanoparticles dispersion and morphology - Mechanical properties of the WUPU/silica nanocomposite fims DOI : 10.1007/s11998-014-9654-z En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-014-9654-z.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24180 [article]

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Effect of the particle sizes of silica on the properties of UV-curing matting coatings / Ziyuan Yang in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 18, N° 1 (01/2021)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 18, N° 1 (01/2021) . - p. 183-192 Titre : Effect of the particle sizes of silica on the properties of UV-curing matting coatings Type de document : texte imprimé Auteurs : Ziyuan Yang, Auteur ; Guozhang Ma, Auteur ; Caiying Hou, Auteur ; Yanxia Niu, Auteur ; Huafeng Duan, Auteur ; Xiaogang Hao, Auteur Année de publication : 2021 Article en page(s) : p. 183-192 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agent mattant Analyse morphologique Caractérisation Copolymère uréthane acrylate Diisocyanate d'isophorone Dioxyde de silicium Oligomères Polyméthacrylate d'hydroxyéthyle Polypropylène glycol Revêtements -- Propriétés mécaniques Revêtements -- Séchage sous rayonnement ultraviolet Revêtements organiques Silice La silice est la forme naturelle du dioxyde de silicium (SiO2) qui entre dans la composition de nombreux minéraux. La silice existe à l'état libre sous différentes formes cristallines ou amorphes et à l'état combiné dans les silicates, les groupes SiO2 étant alors liés à d'autres atomes (Al : Aluminium, Fe : Fer, Mg : Magnésium, Ca : Calcium, Na : Sodium, K : Potassium...). Les silicates sont les constituants principaux du manteau et de l'écorce terrestre. La silice libre est également très abondante dans la nature, sous forme de quartz, de calcédoine et de terre de diatomée. La silice représente 60,6 % de la masse de la croûte terrestre continentale. Stabilité thermique Taille des particules Index. décimale : 667.9 Revêtements et enduits Résumé : UV-curable matting composites were prepared by micron silica matting agent, polyether diol (PPG), isophorone diisocyanate (IPDI), and 2-hydroxyethyl methacrylate (HEMA) via the in situ polymerization method. The structure, surface morphology, and thermal stability of the composites were characterized by FTIR, SEM, and TGA, respectively. As the main resin in the UV-curable coating, the effects of particle sizes of silica on the gloss, abrasion resistance, adhesion, and hydrophilic properties of coatings were measured. The results show that the agglomeration phenomenon of the modified silica in the composite coating was obviously improved. The smaller the particle size, the lower the gloss of coatings with the same content. The adhesion strength and abrasion resistance of the composites were superior to those of pure UV-curing coatings without silica. The greater the particle sizes of the added modified silica, the stronger the hydrophilicity of the composite. Note de contenu : - EXPERIMENTAL : Material - Preparation of PUA and PUA/Sio2 oligomer - Preparation of UV-curing matting coating with PUA/Sio2 oligomer - Instrument and characterization - RESULTS AND DISCUSSION : The structure UV-PUA/Sio2 oligomer - The thermal stability of UV-PUA/SiO2 composite films - Effect of particle size of silica on the surface property of UV-cured films - Effec of particle size of silica on the mechanical property of UV-cured films DOI : https://doi.org/10.1007/s11998-020-00395-4 En ligne : https://link.springer.com/content/pdf/10.1007/s11998-020-00395-4.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35362 [article]

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Extrusion assistée eau appliquée au recyclage des biocomposites / Marie-France Lacrampe in PLASTIQUES & CAOUTCHOUCS MAGAZINE, N° 944 (12/2017)  

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Low monol polyether polyols offer new opportunities for sealant manufacturers / Curt Reichel in ADHESIVES AGE, Vol. 40, N° 1 (01/1997)  

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