Metal-free organocatalysts for high hydrolytic stability single component polyurethane adhesives and their application in decorative insulation facades manufacturing

We focused on developing polyurethane (PU) adhesives with superior ambient thermal and hydrolytic stability, a crucial factor for industrial productivity. Our approach involved creating PU prepolymers that can withstand varying temperatures in ambient conditions. These prepolymers consist of convent...

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Detalles Bibliográficos
Autores: Vallejos, Saúl, Trigo López, Miriam, Sardon, Haritz, González Martín, José Manuel, González Moreno, Sara, García, José María
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Consejo General de la Arquitectura Técnica de España (CGATE)
Repositorio:RIARTE
OAI Identifier:oai:www.riarte.es:20.500.12251/3373
Acceso en línea:http://hdl.handle.net/20.500.12251/3373
https://doi.org/10.1016/j.conbuildmat.2023.132643
Access Level:acceso abierto
Palabra clave:Adhesivos
Colorimetría
Fachadas
Poliuretano
Areniscas siliciclásticas
Aislamiento térmico
Estabilidad térmica
Ensayos (propiedades o materiales)
Material de construcción
3312.08 Propiedades de Los Materiales
3312.12 Ensayo de Materiales
3313.04 Material de Construcción
2211.02 Materiales Compuestos
2304.21 Poliuretanos
2211.29 Propiedades Térmicas de Los Sólidos
Descripción
Sumario:We focused on developing polyurethane (PU) adhesives with superior ambient thermal and hydrolytic stability, a crucial factor for industrial productivity. Our approach involved creating PU prepolymers that can withstand varying temperatures in ambient conditions. These prepolymers consist of conventional isocyanate-terminated polyurethane and metal-free acid:base organic catalysts, with the stability of the adhesive relying on the organocatalyst employed. We tested a series of 11 latent organocatalysts derived from the reaction between 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and various acids. Among these, the catalyst based on 1-naphthoic acid exhibited exceptional stability, lasting at least 3 h at 60 °C and an average relative humidity of 65% under vigorous stirring. We assessed this stability using a fan-based stirrer and analyzed the curing conditions kinetically through DSC. Furthermore, our adhesive formulation is environmentally friendly as it is free of metals, specifically tin (typically present in catalysts such as dibutyltin dilaurate). This quality enhances its sustainability. To validate the practical applicability of the adhesives, we conducted tests using decorative facade models composed of siliciclastic sandstone extracted from a quarry in Vilviestre del Pinar (Burgos, Spain. Latitude: 41.951024° N, longitude: 3.078283° W) and extruded polystyrene (XPS). The results demonstrated the excellent hydrolytic and thermal stability of the adhesives, highlighting their significant potential for panel manufacturing in this context. © 2023 The Author(s)