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Interfacial studies of crosslinked urethanes : part II. The effect of humidity on waterborne polyurethanes ; a spectroscopic study / Anneke M. Kaminski in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 873 (10/1997)

[article]  inJOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 69, N° 873 (10/1997) . - p. 113-121 Titre : Interfacial studies of crosslinked urethanes : part II. The effect of humidity on waterborne polyurethanes ; a spectroscopic study Type de document : texte imprimé Auteurs : Anneke M. Kaminski, Auteur ; Marek W. Urban, Auteur Année de publication : 1997 Article en page(s) : p. 113-121 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 667.9 Revêtements et enduits Résumé : In this study we examined isocyanate crosslinking reactions at the film-air (F-A) and film-substrate (F-S) interfaces of waterborne two-component (2K) urethanes as a function of depth and relative humidity (RH) using attenuated total reflectance (ATR) FTIR spectroscopy. Analysis of water/isocyanate reactions revealed urea formation which further interacts with water via H-bonding. Quantitative analysis of isocyanate consumption showed that the rates of film formation for waterborne polyurethanes are faster than equivalent solvent-borne polyurethanes. These studies showed that isocyanate consumption increases at high relative humidities. Examination of isocyanate consumption as a function of depth from the F-A and F-S interfaces showed that the isocyanate concentration increases when going from 0.65 to 1.14 ?m. Note de contenu : - EXPERIMENTAL : Sample preparation - Analytical methods Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18284 [article]

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Use of a scanning probe microscope to measure marring mechanisms and microhardness of crosslinked coatings / Weidian C. Shen in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 873 (10/1997)

[article]  inJOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 69, N° 873 (10/1997) . - p. 123-135 Titre : Use of a scanning probe microscope to measure marring mechanisms and microhardness of crosslinked coatings Type de document : texte imprimé Auteurs : Weidian C. Shen, Auteur ; Stanley M. Smith, Auteur ; Frank N. Jones, Auteur ; Caigui Ji, Auteur ; Rose Ann Ryntz, Auteur ; M. P. Everson, Auteur Année de publication : 1997 Article en page(s) : p. 123-135 Note générale : Bibliogr. Langues : Américain (ame) Tags : Peinture  'Propriété  mécanique'  Feuil  Dureté  Microdureté  Défaut  'Microscopie  champ  proche'  'Résistance  abrasion' Index. décimale : 667.9 Revêtements et enduits Résumé : A scanning probe microscope (SPM) was equipped with a high-modulus probe to indent coating surfaces when normal force is applied. A method for measuring microhardness with this probe is described. The high-modulus probe was also used to mar coating surfaces under controlled conditions by application of normal force plus lateral motion. Dimensions of the mars were measured by conventional scanning probe microscopy. The data were analyzed in terms of a three response, two mechanism model of marring in which three types of responses of polymeric materials : elastic, plastic deformation, and fracture, are measured. Of the three responses, only plastic deformation and fracture result in marring, and the two mechanisms can be quantified. A fourth quantity which combines plastic deformation and fracture is suggested as a method of comparing micro mar resistance of materials under specified conditions. Three crosslinked polymeric coatings were studied in detail. Two had hard crusts of material near their surfaces that responded quite differently than the bulk of the material. Note de contenu : - EXPERIMENTAL DETAILS : Specimens tested - Preparation of high-modulus probe - Force calibration - Measurement of depth of indentation and calculation of microhardness, Hmic - Hardness measurement by conventional dynamic loading technique - Methods of marring surface : Quantitaive characterization of marring mechanism - Quantitative characterization of responses to marring stress - Empirical mar resistance test - RESULTS : Preparation and calibration of high-modulus probe, measurement of depth of indentation, and calculation of microhardness, Hmic - Methods of marring surfaces : qualitative characterization of marring mechanisms - Quantitative characterization of responses to marring stress - Results of the empirical mar resistance test Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18285 [article]

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Design of pigment dispersants : methodology for selection of anchoring groups / Henk J. W. Van Den Haak in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 873 (10/1997)

[article]  inJOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 69, N° 873 (10/1997) . - p. 137-142 Titre : Design of pigment dispersants : methodology for selection of anchoring groups Type de document : texte imprimé Auteurs : Henk J. W. Van Den Haak, Auteur Année de publication : 1997 Article en page(s) : p. 137-142 Note générale : Bibliogr. Langues : Américain (ame) Tags : Peinture  Adjuvant  Dispersant  'Groupe  fonctionnel'  Adsorption Index. décimale : 667.9 Revêtements et enduits Résumé : The development of pigment dispersants for waterborne or solvent-borne paint systems requires knowledge about anchoring groups, soluble tails, and about an effective and practically feasible architecture to build them together into one molecule.In this paper a method is described for the comparison of the anchoring properties of functional groups. The adsorption of model compounds to pigments from an aqueous solution is measured. From the adsorption isotherms thus obtained, the free energy of adsorption can be calculated, as well as the number of anchoring groups that can adhere to a given weight or surface area of pigment. Note de contenu : - ANCHORING : Theory of adsorption - Real vs. apparent adsorption - INFORMATION FROM THE ADSORPTION MEASUREMENTS : The adsorption capacity A - The strenght of adsorption - Co(adsorption of solvent Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18299 [article]

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