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Reducing product development cycle times without increasing risk / F. Louis Floyd in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 70, N° 876 (01/1998)

[article]  inJOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 70, N° 876 (01/1998) . - p. 71-81 Titre : Reducing product development cycle times without increasing risk Type de document : texte imprimé Auteurs : F. Louis Floyd, Auteur Année de publication : 1998 Article en page(s) : p. 71-81 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Evaluation du risque Production -- Gestion Recherche industrielle Temps de cycle (production) -- Réduction Index. décimale : 667.9 Revêtements et enduits Résumé : Both market forces and the regulatory climate are causing companies to seek ways to accelerate the product development process. Unfortunately, shortening development times usually increases the risk level that a company is forced to live with. Historically, R&D has exercised the role of risk manager in corporations by testing prospective products extensively over long times and under varied conditions to insure that there will be no significant failures, once commercially introduced. Today, this style of risk management is untenable—it simply takes too long and costs too much, without delivering commensurate success. The field of reliability theory offers guidance on how to better understand the sources of risk, and how to quickly assess their magnitude, all on a time scale that allows far more rapid innovation than currently enjoyed in the coatings industry. Better yet, it offers insight on how to accomplish this without increasing the total risk experienced by a company. Note de contenu : - INTRODUCTION : Time pressures - Quality pressures - THE DIMENSIONS OF RISK : Risk perception - Conservative response to risk - Actual Sources of product failures - Managing risk - CURRENT PRODUCT DEVELOPMENT PROTOCOL - HOW CAN WE SAVE TIME? : A fast cycle time example - HOW CAN WE SAVE EVEN MORE TIME ? : Improving our experimental techniques - Shift in traditional roles and relationships - SOFT FINAL THOUGHTS Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17958 [article]

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Oxidative crosslinking of alkyd resins studied with mass spectrometry and NMR using model compounds / W. J. Muizebelt in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 70, N° 876 (01/1998)

[article]  inJOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 70, N° 876 (01/1998) . - p. 83-93 Titre : Oxidative crosslinking of alkyd resins studied with mass spectrometry and NMR using model compounds Type de document : texte imprimé Auteurs : W. J. Muizebelt, Auteur ; J. J. Donkerbroek, Auteur ; M. W. F. Nielen, Auteur ; J. B. Hussem, Auteur ; M. E. F. Biemond, Auteur ; R. P. Klaasen, Auteur ; K. H. Zabel, Auteur Année de publication : 1998 Article en page(s) : p. 83-93 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Esters Huiles et graisses Oxydation Polyalkydes Réticulation (polymérisation) Spectrométrie de masse Spectroscopie de la résonance magnétique nucléaire Index. décimale : 667.9 Revêtements et enduits Résumé : The crosslinking of alkyd resins has been studied using ethyl linoleate and methyl ricinoate as model compounds. With quantitative 13C NMR it was established that ether- and peroxy-crosslinks were formed in roughly equal amounts. Double bonds reacted to give epoxides, endoperoxides, and β-scission into aldehydes. Using SIMS it was established that dimers through pentamers were formed having included several oxygen atoms. After reduction of peroxide (crosslinks) with stannous chloride, the higher oxygen homologues decreased. In the NMR spectrum of the reduced material, peroxide and epoxide signals completely disappeared. High resolution electrospray ionization mass spectra (ESI-MS) yielded evidence regarding the crosslink mechanism. The non-conjugated linoleic acid was found to crosslink by combination of radicals: dimers were having masses 2(M-1). The conjugated linoleic acid crosslinked by addition of radicals to the double bond and disproportionation, yielding masses 2M as well. (M = mass of ethyl linoleate or methyl ricinoate, respectively, including several oxygen atoms.) EIS-MS of oligomers after isotopic exchange enabled estimation of OH and OOH groups. Note de contenu : - EXPERIMENTAL : Materials - Crosslinking of ethyl linoleate and methyl ricinoate - Size-exclusion chromatography - Quantitative 13C NMR - Mass spectrometers - Methods - RESULTS AND DISCUSSION : Oxygen uptake - Size exclusion chromatography - Quantitative 13C NMR - Double bond titration - Mass spectrometry of oligomers - Reduction of peroxides and epoxides with SnCl2 - Electrospray ionization-MS - Exchangeable hydrogen of oligomers - Mechanistic implications - Relevance to coatings systems Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17959 [article]

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Step-growth polymerization of unsaturated aldehydes with diaminodiphenylmethane / Anton Sebenik in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 70, N° 876 (01/1998)

[article]  inJOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 70, N° 876 (01/1998) . - p. 95-100 Titre : Step-growth polymerization of unsaturated aldehydes with diaminodiphenylmethane Type de document : texte imprimé Auteurs : Anton Sebenik, Auteur Année de publication : 1998 Article en page(s) : p. 95-100 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Aldéhydes Un aldéhyde est un composé organique, faisant partie de la famille des composés carbonylés, dont l'un des atomes de carbone primaire (relié au plus à 1 atome de carbone) de la chaîne carbonée porte un groupement carbonyle. L'aldéhyde le plus simple est le formaldéhyde (ou méthanal), aussi appelé formol lorsqu'il est en solution aqueuse. Un aldéhyde dérive formellement d'un alcool primaire (oxydation) dont le groupement hydroxyde -OH est en bout de chaîne et se forme suite à l'enlèvement de deux atomes H d'où le nom "alcool déshydrogéné" ou aldéhyde. Composés insaturés Diaminodiphénylméthane Le 4,4'-diaminodiphénylméthane est une amine aromatique de formule brute C13H14N2 considérée comme dangereuse pour la santé et retirée progressivement du marché européen à partir du 17 février 2011. Le 4,4'-diaminodiphénylméthane est obtenu via une réaction de condensation du formaldéhyde avec l'aniline en présence d'acide chlorhydrique. (Wikipedia) Oligomères Polymérisation Réactions chimiques Thermocinétique Index. décimale : 667.9 Revêtements et enduits Résumé : Step-growth polymerization of diaminodiphenylmethane and unsaturated aldehydes (crotonaldehyde, cinnamaldehyde) proceeded easily in toluene at reflux temperature. Resins with molecular weights up to 1,500 g/mol were formed. In the first step of the reaction, the amino and the aldehyde groups reaction were predominate while the double bonds dominated to a lesser extent. The portion of unreacted monomers was under one percent. The resins consisted of oligomers with -CHNH-, -CH=N-, and -CH=CH-groups, which further reacted to form highly crosslinked resins. Kinetic data, the heat of the addition, the heat of condensation, and the activation energy were calculated. Note de contenu : - EXPERIMENTAL : Materials - Synthesis of the resins - Determination of the heat of addition and condensation - Composition of Resins - RESULTS AND DISCUSSION : Structure of the resins - Molecular weight of resins - Kinetics of addition - The heat of reaction - The heat of addition (Qa) - The heat of condensation - Crosslinking of resins Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17960 [article]

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