Valorization of Kraft Lignin as Thickener in Castor Oil for Lubricant Applications
A. M. Borrero-López1, F. J. Santiago-Medina1, C. Valencia1,2*, M. E. Eugenio3, R. Martin-Sampedro3, J. M. Franco1,2
Journal of Renewable Materials, Vol.6, No.4, pp. 347-361, 2018, DOI:10.7569/JRM.2017.634160
Abstract It is known that large amounts of residual lignin are generated in the pulp and paper industry. A new alternative for Kraft lignin valorization, which consists of first a chemical modification using a diisocyanate and then the efficient dispersion in castor oil to achieve stable gel-like systems, is proposed in this work. Rheological properties and microstructure of these materials were determined by means of small amplitude oscillatory shear tests and viscous flow measurements and atomic force microscopy observations, respectively. Moreover, both standardized penetration tests and tribological assays, usually performed in the lubricant industry, were carried More >