Influence of functional group content in hydroxyl-functionalized urethane methacrylate oligomers on the crosslinking features of clearcoats / Young-Gun June 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. 229-237 Titre : Influence of functional group content in hydroxyl-functionalized urethane methacrylate oligomers on the crosslinking features of clearcoats Type de document : texte imprimé Auteurs : Young-Gun June, Auteur ; Kevin Injoe Jung, Auteur ; Dong Geun Lee, Auteur ; Subin Jeong, Auteur ; Tae-Hee Lee, Auteur ; Young Il Park, Auteur ; Seung Man Noh, Auteur ; Hyun Wook Jung, Auteur Année de publication : 2021 Article en page(s) : p. 229-237 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Basses températures Liants Méthacrylate d'uréthane Oligomères Réticulants Réticulation (polymérisation) Revêtements organiques Vernis Index. décimale : 667.9 Revêtements et enduits Résumé : Crosslinking characteristics and surface mechanical properties of radical and urethane dual-curable clearcoats were investigated by changing quantities of C=C bonds and OH groups in hydroxyl-functionalized urethane methacrylate oligomer (HFUMO) resins. The isocyanate blocked with a thermal radical initiator (BL-Tri-cHD) was utilized as a hybrid dual-curable thermal crosslinker to expedite the crosslinking of the main resin. The dual reactions between various HFUMO resins and BL-Tri-cHD were efficiently monitored via Fourier transform infrared spectroscopy to measure the peaks before and after curing. The influence of each functional group (C=C bond or OH group) in HFUMO on the initiation and development of crosslinking in dual-curable clearcoats was investigated by real-time measurements using rotational rheometer and rigid body pendulum tester. Temperature-dependent mechanical properties of cured films were confirmed through dynamic mechanical analysis. The surface mechanical properties of cured clearcoat films were also evaluated via the nanoindentation and nanoscratch tests, demonstrating the variation in surface resistance with respect to the C=C bond content and the OH value. Thus, the low-temperature curing and desired mechanical properties of clearcoats can be optimized by adjusting the content of the functional groups in a HFUMO and using a dual-curable crosslinker to simultaneously generate both radical and urethane crosslinking reactions. Note de contenu : - EXPERIMENTAL METHOS : Synthesis of HFUMOs and blocked isocyanate using a TRI (BL-Tri-cHD) - Formulation of clearcoats with various HFUMO resins - Variations in functional groups by FTIR analysis - Real-time crosslinking behaviors of HFUMO-based clearcoats - Dynamic mechanical analysis of cured films - Surface mechanical properties of cured films - RESULTS AND DISCUSSION : FTIR analysis of clearcoats with varying quantities of functional groups in HFUMOs - Rheological analysis of crosslinking behavior - Analysis of curing behaviors using RPT - Dynamic mechanical analysis - Indentation depth profiles - Scratch depth profiles - Table 1 : Formulation of clearcoat mixtures with various HFUMOs with different contents of C=C bond and OH group DOI : https://doi.org/10.1007/s11998-020-00398-1 En ligne : https://link.springer.com/content/pdf/10.1007/s11998-020-00398-1.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35365 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
22605	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The effect of thermal radical initiator derived from O-imino-isourea on thermal curing characteristics and properties of automotive clearcoats / Ji Won Hwang in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 12, N° 1 (01/2015)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 12, N° 1 (01/2015) . - p. 177-186 Titre : The effect of thermal radical initiator derived from O-imino-isourea on thermal curing characteristics and properties of automotive clearcoats Type de document : texte imprimé Auteurs : Ji Won Hwang, Auteur ; Kyung Nam Kim, Auteur ; Seung Man Noh, Auteur ; Hyun Wook Jung, Auteur Année de publication : 2015 Article en page(s) : p. 177-186 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Amorceurs (chimie) Automobiles -- Vernis Hydroxyle En chimie organique, un hydroxyle (ou oxhydryle) peut désigner deux entités. Un groupement -OH, appelé aussi hydroxy, qui se rencontre en particulier dans les alcools et les phénols. Un radical : HO^{\bullet}. Il est produit par exemple lors de réactions de dissociation de peroxydes, en présence d'ions de métaux de transition (Fe(II), Cu(I), réaction de Fenton), de chauffage ou de rayonnement. Mélamine La mélamine, de nom chimique 1,3,5-triazine-2,4,6-triamine, est parfois dénommée cyanuramide ou cyanurotriamine. Sa formule brute est C3H6N6. Les "résines mélamine-formaldéhyde" ou "mélamine-formol" (sigle MF) sont appelées "mélamine" dans le langage courant. Elles font partie de la famille des aminoplastes qui regroupe des résines thermodurcissables aminées, issues d'un comonomère tel l'urée ou la mélamine, parfois le thiocarbamide, le cyanamide hydrogène ou le dicyandiamide ; le second comonomère étant le formaldéhyde. Méthacrylate d'uréthane Oligomères Polyaddition Résistance à l'abrasion Réticulation (polymérisation) Rhéologie Vernis -- Propriétés mécaniques Index. décimale : 667.9 Revêtements et enduits Résumé : Curing characteristics of melamine-based automotive clearcoats with or without thermal radical initiator (TRI) derived from an O-imino-isourea have been examined by means of their real-time rheological properties during a thermal curing process. By changing functionalities of reactive sites at hydroxyl groups and unsaturated double bonds in hydroxyl-functionalized urethane methacrylate oligomer as a main binder, the effect of TRI on various properties of thermally cured clearcoats has been compared by means of rheological, rigid-body pendulum, ultra nano-indentation, and nano-scratch tests. It was found that a small portion of TRI significantly enhanced the final elastic modulus of clearcoats with the lower content of hydroxyl groups and considerably shortened curing time, implying the formation of denser crosslinked networks inside clearcoats by the free-radical polymerization at relatively lower curing temperature. These results were directly linked with the improvement of their mechanical properties such as indentation hardness and scratch resistance. TRI plays a key role in desirably controlling the rheological and mechanical properties of clearcoats under insufficient thermal curing conditions. Note de contenu : - EXPERIMENTAL : Preparation of clearcoat samples - Characterization methods - RESULTS AND DISCUSSION : Thermal characteristics of clearcoats - Comparison of elastic rheological data for clearcoats with or without TRI - Curing characteristics by RPT tests - Mechanical properties of cured clearcoats DOI : 10.1007/s11998-014-9619-2 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-014-9619-2.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=23216 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
16952	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The influence of methacrylic acid and urethane methacrylate on the film properties of hybrid urethane–acrylic latexes in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 18, N° 6 (11/2021)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 18, N° 6 (11/2021) . - p. 1557-1577 Titre : The influence of methacrylic acid and urethane methacrylate on the film properties of hybrid urethane–acrylic latexes Type de document : texte imprimé Année de publication : 2021 Article en page(s) : p. 1557-1577 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation Composés organiques -- Synthèse Copolymère uréthane acrylique Extrait sec Formation de film Formulation (Génie chimique) Granulométrie Méthacrylate d'uréthane Méthacrylique, Acide L'histoire de l'acide méthacrylique commence en 1865, année où il est synthétisé pour la première fois à partir du méthacrylate d'éthyle. L'acide méthacrylique est très réactif avec les groupes carboxyles, vinyles et esters. Poids moléculaires Revêtements -- Propriétés mécaniques Revêtements -- Propriétés thermiques Revêtements organiques Transition vitreuse Viscoélasticité Index. décimale : 667.9 Revêtements et enduits Résumé : A non-isocyanate pathway was used to synthesize a urethane methacrylate monomer, 2-((methylcarbamoyl)oxy)ethyl methacrylate (MEM) and methacrylic acid (MAA). The MEM and MAA mixture was copolymerized with MMA and BA in a semicontinuous monomer-starved process to prepare latexes via emulsion polymerization. Varying amounts of MEM and MAA monomers were introduced to the latex, and their effect on the thermal properties, film formation, viscoelastic, mechanical and morphological properties was examined. The upper limit functionality concentration was evaluated based on the latex stability. Incorporation of MEM and MAA in latexes enhanced film formation properties displayed by lowering MFFT. MEM and MAA functionalized latexes exhibited enhanced Young’s modulus, tensile strength and hardness compared to the control latex without any MEM and MAA. Note de contenu : - EXPERIMENTAL : Materials - Instrumentation - Synthesis of monomers and latexes - Synthesis of latexes - Latex characterization - RESULTS : Characterization of MEM+MAA - Latex conversion, particle size and molecular weight - Thermal properties and film formation - Viscoelastic properties - Mechanical properties - Morphological properties—TEM - Morphological properties—AFM - Coatings properties - Table 1 Latex formulations for 0, 2, 5 and 10 mol% MEM+MAA - Table 2 Solids content, overall conversion, particle size and Mw− results of MEM+MAA latexes - Table 3 Glass transition temperature, minimum film formation temperature, and their difference for MEM+MAA latexes - Table 4 Viscoelastic properties of MEM+MAA latexes as a function of increasing functionality of MEM+MAA - Table 5 Roughness data for 0, 2, 5 and 10 mol% MEM+MAA latex - Table 6 Coatings tests results for MEM+MAA latexes as a function of increased functionality from 0 to 10 mol% DOI : https://doi.org/10.1007/s11998-021-00497-7 En ligne : https://link.springer.com/content/pdf/10.1007/s11998-021-00497-7.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=36808 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
23146	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Urethane methacrylate reactive diluents for UV-curable polyester powder coatings / Theodore J. Hammer in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 18, N° 2 (03/2021)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 18, N° 2 (03/2021) . - p. 333-348 Titre : Urethane methacrylate reactive diluents for UV-curable polyester powder coatings Type de document : texte imprimé Auteurs : Theodore J. Hammer, Auteur ; Hamideh M. Shokouhi Mehr, Auteur ; Coleen Pugh, Auteur ; Mark D. Soucek, Auteur Année de publication : 2021 Article en page(s) : p. 333-348 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse mécanique dynamique Caractérisation Composés organiques -- Synthèse Diluants Formulation (Génie chimique) Méthacrylate d'uréthane Polyesters Revêtements organiques Revêtements poudre Stabilité au stockage Viscosité Index. décimale : 667.9 Revêtements et enduits Résumé : Three urethane methacrylates, one monofunctional derivative and two di-functional derivatives with different chain lengths were used as reactive diluents in UV-curable polyester powder coatings. Each reactive diluent was formulated with a methacrylated polyester oligomer using conventional melt extrusion techniques. The effect of these compounds on zero-shear melt viscosity was investigated. Incorporation of 10 wt% reactive diluent effectively reduced the viscosity by an order of magnitude. After UV-curing, the viscoelastic, thermal, and mechanical properties of the films were characterized using dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, and tensile tests. The type and concentration of reactive diluent that was used directly influenced the glass transition temperature, modulus, % elongation-at-break, and crosslink density. Of the two di-functional reactive diluents that were used, the derivative that contained a shorter methylene spacer group resulted in more heterogeneous crosslinked networks. Note de contenu : - EXPERIMENTAL : Materials - Techniques and instrumentation - Synthesis of hydroxyl-terminated polyester - Synthesis of methacrylated polyester (MPE) - Synthesis of bis(2-hydroxyethyl)hexane-1,6-diyldicarbamate (1A) - Synthesis of 4,13-dioxo-3,14-dioxa-5,12-diaza hexadecane-1,16-diyl bis(2-methylacrylate) (HDA-EC) (1B) - Synthesis of bis(2-hydroxyethyl) ethane-1,2-diyldicarbamate (2A) - Synthesis of 4,9-dioxo-3,10-dioxa-5,8-diazadodecane-1,12-diyl bis(2-methacrylate) (2B) - Synthesis of 2-hydroxyethyl dodecylcarbamate (3A) - Synthesis of 2-((dodecylcarbamoyl)oxy)ethyl methacrylate (DDA-EC) (3B) - Acid number calculations - Powder coating formulation and application - Thin-film preparation for DMA and tensile testing - RESULTS : Synthesis of MPE resin - Synthesis of urethane methacrylates - Viscosity - Thermal properties - Mechanical and viscoelastic properties - Gel content - Wide-angle X-ray scattering - General coatings tests - Table 1 : Example formulation of 5_EDA-EC - Table 2 : Summary of the DSC and TGA data obtained from the various UV-cured samples - Table 3 : Summary of the viscoelastic data obtained from DMA experiments - Table 4 : Summary of the general coatings tests and storage stability analysis DOI : https://doi.org/10.1007/s11998-020-00391-8 En ligne : https://link.springer.com/content/pdf/10.1007/s11998-020-00391-8.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35598 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
22701	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 4 / 4)