From Levulinic Acid to Imines: Creating Biobased, Recyclable, Cross-linked Rubbers through Covalent Adaptive Networks

Dynamic covalent bonds provide a powerful tool to design recyclable rubber-based materials. Among possible strategies, imine chemistry offers a valuable approach for achieving an adaptive network. In this work, for the first time, the use of biobased ketones and amines as cross-linkers in a rubber n...

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Detalhes bibliográficos
Autores: Lenzi, Luca, Chicharro, Juan Carlos, Esposti, Micaela Degli, Morselli, Davide, Hernández, Marianella, Fabbri, Paola
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2025
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/402313
Acesso em linha:http://hdl.handle.net/10261/402313
Access Level:Acceso aberto
Palavra-chave:covalent adaptive network
rubber
iminebonds
hydrogenbonds
recycling
levulinicacid
biobased
Descrição
Resumo:Dynamic covalent bonds provide a powerful tool to design recyclable rubber-based materials. Among possible strategies, imine chemistry offers a valuable approach for achieving an adaptive network. In this work, for the first time, the use of biobased ketones and amines as cross-linkers in a rubber network is used. Specifically, epoxidized natural rubber (ENR) was cross-linked with glycerol trilevulinate (GT) and hexamethylene diamine (HMDA) to produce a fully biobased and recyclable hybrid network based on imine and hydrogen bonds. Comprehensive characterization confirmed the formation of a hybrid adaptive network, while mechanical tests demonstrated that the optimal formulation (5 phr GT and 5 phr HMDA) achieved the best performance after recycling, showing a significant increase in tensile strength while maintaining stable strain at break. The material's ability to reconstruct its network upon reprocessing was supported by cross-link density measurements via swelling and mechanical analyses, while dielectric investigations further confirmed the presence of dynamic interactions. The observed recyclability was thus attributed to the synergistic effect of covalent and noncovalent bonds, which reorganized effectively to preserve network integrity and mechanical performance. This work demonstrates the potential production of a biobased, recyclable and adaptable rubber network with excellent mechanical properties, highlighting how levulinic acid derivatives represent an optimal system for the development of sustainable rubber materials.