title: Polyurethane foam impregnated with lignin as a filler for the removal of crude oil from contaminated water.
abstract: The present study describes the influence of the concentration of lignin when used as a filler in polyurethane foam for crude oil sorption. The foams (lignin 0-20wt%) were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis, contact angle and density. The FTIR analysis confirmed urethane linkage formation, showing that the chemical structure of the polymer was preserved, despite the addition of different lignin concentrations. Thermogravimetric analysis showed that the presence of lignin has altered the onset temperature (Tonset) of the foams, decreasing as the concentration of lignin is increased. The contact angle analysis showed a decrease in the hydrophobicity of the foams with increasing lignin concentration. All modified foams showed an improvement in the oil sorption capacity in a PUF/oil/water system, and the PUF-10 showed an improvement of about 35.5% compared to the PUF-blank. The Langmuir isotherm showed a better fit to the data and predicted a maximum oil adsorption of 28.9gg-1by the PUF-10. The ΔG° value of -4.4kJmol-1indicated that crude oil adsorption process by PUF-10 was spontaneous. The results of reuse of the PUF-10 showed that oil removal efficiency remained greater than 95% after five consecutive cycles.
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, CEP: 31.270-901, Brazil.
authors.forename: O S H
authors.initials: OS
authors.lastname: Santos
authors.affiliation: Engenharia de Materiais, Universidade Federal de Itajubá-UNIFEI, Campus Universitário de Itabira. Itabira, Minas Gerais, CEP: 35.903-087, Brazil.
authors.forename: Mercês
authors.initials: M
authors.lastname: Coelho da Silva
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, CEP: 31.270-901, Brazil.
authors.forename: V R
authors.initials: VR
authors.lastname: Silva
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, CEP: 31.270-901, Brazil.
authors.forename: W N
authors.initials: WN
authors.lastname: Mussel
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, CEP: 31.270-901, Brazil. Electronic address: mirene@ufmg.br.
authors.forename: M I
authors.initials: MI
authors.lastname: Yoshida
keywords: Environmental contamination; Isotherms; Lignin; Oil removal; Polyurethane foam