Characterization of Lignin Precipitated From The Soda Black Liquor of Oil Palm Empty Fruit Bunch Fibers by Various Mineral Acids

Abstract

Soda lignin from oil palm empty fruit bunch was directly isolated by various mineral acids i.e. sulfuric acid, hydrochloric acid, phosphoric acid and nitric acid at three levels of concentration (20% v/v, 60%v/v and concentrated). A comparison study was performed through physicochemical properties and structural features using FT-IR, UV, 13 C-NMR and nitrobenzene oxidation. The FT-IR results showed that there is no significant difference between the main structures of the lignin isolated by various acids. However, low concentration of phosphoric acid is preferable because of its highest yield. The S: V: H ratio of 7-15:6-11:1 as evaluated by the nitrobenzene oxidation procedure suggests that soda lignin can be classified as belonging to either the cereal straw on grass type. The UV results indicate that phosphoric acid consistently gave the highest absorbance value among the four acids tested in this study regardless of its concentration level. The C 13 -FTNMR spectra, suggest that the lignin structure is independent of the type of acid used for precipitation.

Green synthesis of lignin nano- and micro-particles: Physicochemical characterization, bioactive properties and cytotoxicity assessment

“…This band is related to the presence of alcoholic and phenolic hydroxyl groups involved in hydrogen bonds. The absorption bands located at 2930 and 2850 cm −1 arising from the symmetrical and asymmetrical C\ \H stretching of the methyl and methylene groups were also founded in the three samples (lignin and LPs) [45][46][47].…”

The inhibition of hepatic and renal glucuronidation of p-Nitrophenol and 4-Methylumbelliferone by oil palm empty fruit bunch lignin and its main oxidation compounds

“…Both precipitates were filtered and washed with distilled water at pH 2.0, which was prepared using the same acid as in the earlier step. The soda and kraft lignin were dried in an oven at 55°C for 24 h.[ 30 ] The preparation of organosolv OPEFB lignin was carried out by washing the pretreated EFB with warm ethanol/water (8:1, 3 × 50.0 mL). The washes were combined and 3 volumes of water were added to precipitate the ethanol organosolv lignin, which was collected by centrifugation and air dried.…”

Inspired by Skeletal Muscles: Study of the Physical and Electrochemical Properties of Derived Lignocellulose-Based Carbon Fibers

“…The -OH stretching vibrations are observed between 3100 and 3500 cm -1 ; the bands between 2700 and 3000 cm -1 are attributed to the C-H stretching vibrations of the alkyl group [37][38][39]; the characteristic absorption bands are observed at 1645, 1647, 1660, 1730, and 1733 cm -1 , corresponding to C=O derived from aldehyde and carboxyl [42]; and the bands at 1040, 1050, and 1052 cm -1 correspond to C-O/C-O-C stretching vibrations. The IR absorption peaks of poplar lignin at 1601, 1513, and 1464 cm −1 are attributed to characteristic stretching vibrations of the aromatic skeleton [29,43], which are observed in the FTIR spectrum of the L-precursor at 1610, 1510, and 1450 cm −1 , respectively. Notably, compared with those of poplar lignin and MCC, the peak intensity of the -OH band in the FTIR spectrum of L-precursor decreases, and a new IR peak is observed at 1261 cm -1 , corresponding to fatty amine [5,44,45].…”