RT Journal Article
T1 Unexpected Selectivity in the Functionalization of Neat Castor Oil under Benign Catalyst-Free Conditions
A1 Raghunanan, Latchmi C.
A1 Martinez García, Inmaculada
A1 Valencia Barragán, Concepción
A1 Sánchez Carrillo, María Carmen
A1 Franco Gómez, José María
K1 Functionalization
K1 Lipids
K1 Materials
K1 Molecules
K1 Selectivity
AB We present herein an unexpected selectivity in the reactions of castor oil with 1,6-hexamethylene diisocyanate (HMDI) in the absence of catalysts, heat or N2 protection to give monofunctionalized castor oil derivatives. The reagents were stirred at room temperature for 24 h, and the resulting formulations characterized with infrared spectroscopy, thermogravimetric analysis and NMR. In the highly viscous neat systems, the reaction stops at the formation of NCO-terminated urethane monomers. When the mass transfer limitations due to high viscosity are minimized, the NCO-terminated urethane monomers go on to form not di- or tri- urethane monomers, but cross-linked monourethane dimers. We propose that the selectivity of the functionalization reaction of castor oil originates from a hydrogen bonding mediated steric hindrance on two out of the three fatty acid moieties. This selectivity is normally associated with conformational preferences in crystallized triglycerides, and indicates an inherent level of structuring of the ricinolein molecules of neat castor oil. These findings indicate that unprecedented selective functionalization of triglycerides can be achieved under benign conditions, most notably without catalysts, representing a significant advancement for the production of more sustainable polymeric materials from renewable resources.
PB American Chemical Society
SN 2168-0485
YR 2018
FD 2018-04
LK https://hdl.handle.net/10272/25255
UL https://hdl.handle.net/10272/25255
LA eng
NO Raghunanan, L. C., Martínez, I., Valencia, C., Sánchez, M. C., & Franco, J. M. (2018). Unexpected Selectivity in the Functionalization of Neat Castor Oil under Benign Catalyst-Free Conditions. In ACS Sustainable Chemistry & Engineering (Vol. 6, Issue 6, pp. 7212–7215). American Chemical Society (ACS). https://doi.org/10.1021/acssuschemeng.8b00979
NO The authors gratefully acknowledge the financial support of the European Union (EU) for this work, performed under the research project ISSFLOW-FP7-PEOPLE-2013-IAPP-612330.
DS Repositorio Institucional de la Universidad de Huelva
RD 30 may 2026