RT Journal Article T1 Structure-property relationships in solvent free adhesives derived from castor oil A1 Santan, Harshal D. A1 James, Craig A1 Fratini, Emiliano A1 Martinez García, Inmaculada A1 Valencia Barragán, Concepción A1 Sánchez Carrillo, María Carmen A1 Franco Gómez, José María AB A method to prepare solvent free castor oil (CO) based polyurethane (PU) adhesives with different ratios of CO and hexamethylene diisocyanate (HMDI) has been developed and the relationships between the microstructure and mechanical properties investigated. Solvent free castor oil-based PU adhesives were synthesized by promoting the reaction between castor oil and HMDI, at room conditions, and by varying the CO/HMDI weight ratio in the range 1:0.032–1:0.32 wt%. The curing of these adhesives did not require any external stimuli such as heat or irradiation treatment and once cured at room temperature they were stable up to 140 °C and water-resistant. A multi-technique approach was used to characterize so-obtained adhesives. The adhesion energy in metal–metal contact was evaluated as a function of the debonding velocity (Vd) through tack experiments. The mechanical properties were influenced by the NCO/OH ratio, which varies the crosslinking density in the adhesives. Moreover, the structure–mechanical property relationship was explored and the inter-correlation between the storage modulus (G’), adhesion energy (Ead) and correlation length (ξ) detailed, with both G’, Ead increasing while ξ decreased. These solvent-free bio-based adhesives showed capability to adhere different substrates such as wood, paper, textile, and metal, which makes them promising candidates in different industrial and commercial applications. PB Elsevier SN 0926-6690 SN 1872-633X (electrónico) YR 2018 FD 2018-10 LK https://hdl.handle.net/10272/25239 UL https://hdl.handle.net/10272/25239 LA eng NO Santan, H. D., James, C., Fratini, E., Martínez, I., Valencia, C., Sánchez, María. C., & Franco, J. M. (2018). Structure-property relationships in solvent free adhesives derived from castor oil. In Industrial Crops and Products (Vol. 121, pp. 90–98). Elsevier BV. https://doi.org/10.1016/j.indcrop.2018.05.012 NO This work is a part of research project ISSFLOW (Project ID: 612330) sponsored by European Union under the program FP7-PEOPLE. The authors also acknowledge partial financial support from the Consorzio per lo sviluppo dei Sistemi a Grande Interfase (CSGI). DS Repositorio Institucional de la Universidad de Huelva RD 1 jun 2026