Fecha de publicación: 29/11/2024 Fuente: Polymers Polymers, Vol. 16, Pages 3356: Enhanced Green Strength in a Polycarbonate Polyol-Based Reactive Polyurethane Hot-Melt Adhesive
Polymers doi: 10.3390/polym16233356
Authors:
Alejandra Moyano-Vallejo
María Pilar Carbonell-Blasco
Carlota Hernández-Fernández
Francisca Arán-Aís
María Dolores Romero-Sánchez
Elena Orgilés-Calpena

This study aimed to enhance the initial adhesion performance of reactive polyurethane hot-melt adhesives by using a bio-based polycarbonate polyol instead of traditional polyester or polyether polyols and by incorporating thermoplastic polyurethane (TPU) in varied proportions. Adhesives synthesized from bio-based polycarbonate polyols and polypropylene glycol with MDI as the isocyanate were characterized chemically, thermally, and mechanically (FTIR, DSC, plate–plate rheology, DMA, and T-peel strength test). Adding 10–15 wt.% TPU significantly improved green strength and initial adhesion at room temperature and after accelerated cooling. The bio-based polycarbonate polyol promotes superior flexibility at low temperatures compared to fossil-derived alternatives, aligning with sustainability objectives. The results showed that 10 wt.% TPU maximized green strength without compromising flexibility, whereas 15 wt.% TPU, though enhancing adhesion, reduced flexibility due to increased crystallinity. T-peel tests on footwear materials indicated that all the adhesives exceeded the EN 15307:2015 requirements, with the highest peel strength achieved after curing. These findings highlight the benefit of bio-based polycarbonate polyols and TPUs in achieving strong, flexible, and eco-friendly adhesives suitable for demanding applications.