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Environmental fate and effects of dimethicone and cyclotetrasiloxane from personal care applications / C. Stevens in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 20, N° 5 (10/1998)
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Titre : Environmental fate and effects of dimethicone and cyclotetrasiloxane from personal care applications Type de document : texte imprimé Auteurs : C. Stevens, Auteur Année de publication : 1998 Article en page(s) : p. 297-305 Note générale : Bibliogr. Langues : Anglais (eng) Tags : Dimethicone Cyclotetrasiloxane Environmental degradation effects Monitoring data Index. décimale : 668.5 Parfums et cosmétiques Résumé : This paper summarizes the environmental fate and effects of dimethicone and cyclotetrasiloxane, which are used extensively in personal care applications. Dimethicone and cyclotetrasiloxane differ fundamentally in their physicochemical properties, and as a consequence display different environmental fate paths. Cyclotetrasiloxane partitions into the atmosphere, whereas sediments and soils are the most important environmental compartments for dimethicone. Information is presented to show the environmental degradation of these two materials in their respective environmental compartments. In both cases, after a non-biological step to initiate the process, the degradation occurs biologically. Ultimately, both dimethicone and cyclotetrasiloxane are degraded to inorganic constituents, carbon dioxide, silicic acid and water. No adverse effects have been detected in experimental organisms representative of the environmental compartments in which dimethicone and cyclotetrasiloxane may be found. Monitoring of key environmental compartments, namely sediments and soil, reveals that average concentrations are well below the no-observed adverse effect level. This work therefore continues to support the environmental acceptability of dimethicone and cyclotetrasiloxane for personal care applications. DOI : 10.1046/j.1467-2494.1998.181595.x En ligne : https://onlinelibrary.wiley.com/doi/10.1046/j.1467-2494.1998.181595.x Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5008
in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 20, N° 5 (10/1998) . - p. 297-305[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 003975 - Périodique Bibliothèque principale Documentaires Disponible Dimethyl secondary amine chain extenders : a conceptual approach to in situ generation of advanced epoxy resins for rapid-cure, low-VOC coatings / Frederick H. Walker in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 6, N° 3 (09/2009)
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Titre : Dimethyl secondary amine chain extenders : a conceptual approach to in situ generation of advanced epoxy resins for rapid-cure, low-VOC coatings Type de document : texte imprimé Auteurs : Frederick H. Walker, Auteur ; Rob Rasing, Auteur ; Gamini A. Vedage, Auteur ; Michael Cook, Auteur Année de publication : 2009 Article en page(s) : p. 283-313 Note générale : Bibliogr. Langues : Américain (ame) Tags : Poly(N-methylazetidine) Dimethyl-meta-xylylenediamine Pseudo-first-order kinetic Amine reactivity epoxy curing agent Epoxy resin coating Flexibility Crosslink density Miller-Macosko calculation Chain extender VOC Low temperature cure Environmental movement Electrochemical impedance Aine reaction mechanism Mannich base Index. décimale : 667.9 Revêtements et enduits Résumé : Advanced epoxy resin oligomers have traditionally been utilized for coatings that combine fast dry-to-touch speed and good flexibility--properties demanded in many markets such as marine and industrial maintenance coatings. Unfortunately, advanced epoxy resins require formulation with large quantities of solvent that make attainment of modern VOC regulations difficult or impossible. Coatings formulated from low molecular weight liquid epoxy resin, on the other hand, can easier meet VOC challenges, but dry slowly and tend to be brittle. This presentation explores the concept of using fast reacting, di-functional amine chain extenders to generate epoxy oligomers in situ as a means to meet these opposing property demands. Methylamine-terminated poly-(N-methylazetidine) (pNMAz, 1) is prepared in a two-step process involving the Michael addition of methylamine to acrylonitrile, followed by hydrogenation in a methylamine-containing atmosphere to yield an oligomer stream with an [M.sub.n] of about 250. Competitive pseudo-first-order kinetic measurements conducted in isopropyl alcohol indicate methyl-substituted disecondary diamines reacted approximately 3 to 3.6 times faster with phenyl glycidyl ether (PGE) than the primary amine meta-xylylenediamine (MXDA). These chain extenders can be formulated with traditional multi-functional amine crosslinkers to yield coatings with lower VOC, faster dry speed, and better flexibility compared to corresponding coatings formulated without the chain extender. DOI : 10.1007/s11998-009-9178-0 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-009-9178-0.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=6111
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 6, N° 3 (09/2009) . - p. 283-313[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 011503 - Périodique Bibliothèque principale Documentaires Disponible