@article{10272/20265,
year = {2021},
month = {7},
url = {http://hdl.handle.net/10272/20265},
abstract = {Thickening vegetable oils to different extents is of
great interest in the design and development of new bio-based
lubricant formulations, as achieving a wide range of rheological
properties is crucial to the successful replacement of petroleumbased
traditional counterparts. With this aim, the influence of
epoxidation degree, modified by altering the reaction conditions,
on the viscous flow properties of epoxidized castor oil was
investigated together with the incorporation of a lignin-enriched
fraction from sugarcane bagasse waste to more extensively modify
the rheological properties, thereby valorizing this waste fraction.
Oil thickening was achieved by promoting the cross-linking
between the epoxidized oil and the lignin-enriched fraction that
enables the compatibilization of both components. Castor oil
epoxidation was assessed by means of standard volumetric titration methods and infrared spectroscopy. In addition, a fully
rheological characterization of both epoxidized and lignin-thickened castor oils was carried out. A hydrodynamic approach was also
followed, aiming to provide an estimation of the Mark−Houwink−Sakurada parameters and relate the intrinsic viscosity with the
average molecular weight of the resulting epoxidized castor oil/lignocellulose macromolecular compounds. The chemical interaction
between castor oil and the lignocellulosic material increased as the extent of epoxidation was increased, yielding a variety of
rheological responses from Newtonian liquids of increasing viscosities (from around 1 to 500 Pa·s) to viscoelastic liquids.},
organization = {Funding for open access charge: Universidad de Huelva / CBUAThis work is part of a research project (RTI2018-096080-B-
C21) sponsored by the MICINN-FEDER I+D+i Spanish

Programme. The financial support is gratefully acknowledged.
The authors are also grateful to Dr. Ignacio Ballesteros (CIEMATMadrid, Spain) for kindly providing the ligninenriched waste fraction used in this study.},
publisher = {American Chemical Society},
title = {Thickening Castor Oil with a Lignin-Enriched Fraction from Sugarcane Bagasse Waste via Epoxidation: A Rheological and Hydrodynamic Approach},
doi = {10.1021/acssuschemeng.1c02166},
author = {Cortés Triviño, Esperanza and Valencia Barragán, Concepción and Franco Gómez, José María},
}