Titre : |
Dual-curable coatings obtained from multi-functional non-isocyanate polyurethane oligomers |
Type de document : |
texte imprimé |
Auteurs : |
H. R. Asemani, Auteur ; V. Mannari, Auteur |
Année de publication : |
2022 |
Article en page(s) : |
p. 1393-1407 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Caractérisation Décomposition (chimie) Dureté (matériaux) Impédancemétrie Matériaux -- Propriétés fonctionnelles Oligomères Poids moléculaires Polyuréthanes Réticulation à l'humidité Revêtements -- Propriétés mécaniques Revêtements organiques Revêtements sans isocyanates Temps de séchage
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
The growing concerns and impending regulations on the usage of monomeric isocyanates in the production of polyurethane resins have led to the introduction of alternative non-isocyanate polyurethane (NIPU) systems. Although two-component NIPU coatings based on the reaction of cyclic carbonates and aliphatic amines have emerged as a promising option, they are still associated with two significant drawbacks: lower crosslinking densities due to reduced functionality of the oligomers and low ambient-temperature reactivity. This study reports the utilization of a hybrid approach to address these drawbacks. Amine-functional NIPU oligomers (NI-PUPA) were synthesized by the reaction of cycloaliphatic amine functional compounds and multi-functional cyclic carbonates in an excess amine molar ratio. After mixing the NI-PUPAs with (3-glycidyloxypropyl) trimethoxysilane (GPTMS), a dual-curable coating could be achieved by ambient curing of amines and epoxies and moisture curing of alkoxy silanes. A comparative experimental design was implemented to evaluate the effect of an additional curing mechanism. The results revealed that the additional moisture curing led to faster ambient curing, faster development of properties, enhanced flexibility even at higher crosslinking densities, and better corrosion resistance. Such advancement could facilitate the future implementation of NIPUs in high-performance ambient-curing coating applications. |
Note de contenu : |
- EXPERIMENTAL : Materials - Methods - Testing, characterization, and evaluation
- RESULTS AND DISCUSSION : Characterization of NI-PUPAs - Curing characterization - Cured film properties
- Table 1 : Molecular weights obtained from GPC analysis in comparison with theoretical values and the values obtained by amine value titration
Table 2 : The tack-free and through-dry times of NIPU coatings based on ASTM D5898 standard
- Table 3 :Konig pendulum hardness development for NIPU coatings over 7 days of curing time (method: ASTM D4366; unit: number of oscillations)
- Table 4 :MEK double-rub development for NIPU coatings over 7 days of curing time
- Table 5 :Properties of NIPU coatings after 7 days of curing at ambient conditions
- Table 6 :Impedance at low frequencies and pore resistance values obtained from EIS analysis
- Table 7 : Decomposition temperatures and residual wt.% obtained by the analysis of TGA thermograms |
DOI : |
https://doi.org/10.1007/s11998-022-00614-0 |
En ligne : |
https://link.springer.com/content/pdf/10.1007/s11998-022-00614-0.pdf |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38278 |
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 19, N° 5 (09/2022) . - p. 1393-1407