Physico-chemical and thermal characterization of lignins from Caligonum monogoliacum and Tamarix spp.

Biorefinery Process Combining Specel® Process and Selective Lignin Precipitation using Mineral Acids

“…The thermal degradation in this region involved fragmentation of inter-unit linkages between phenolic hydroxyl, carbonyl, and benzylic hydroxyl groups, releasing monomeric phenols (El-Saied and Nada 1993; Domínguez et al 2008;González et al 2009). At temperatures above approximately 450 °C, it was observed that the third and last stage was due to the condensation and/or decomposition reactions of the aromatic rings (Sun et al 2001;Domínguez et al 2008). …”

Comparative study of three lignin fractions isolated from mild ball‐milled Tamarix austromogoliac and Caragana sepium

“…31 In this study, UV-vis absorption measurements of the acid-insoluble lignin fractions were carried out with a dioxane/water mixture, which solubilized the lignins but was limited to wavelengths above 240 nm. Figure 2 illustrates the UV spectra of acid-insoluble lignin fractions L 1T , L 2T , and L 3T [ Fig.…”

“…Moreover, the shift of the maximum wavelength from 274 (L 1T , L 2T , and L 3T ) to 280 nm (L 1C , L 2C , and L 3C ) suggested a higher content of syringyl (S) units in lignin fractions L 1T , L 2T , and L 3T isolated from the mild ball-milled TA because S units exhibit the bands at somewhat shorter wavelengths, specifically at 268-277 nm. 31 The composition of associated hemicelluloses in the six isolated acid-insoluble lignin fractions was determined by their neutral sugar and uronic acid contents, and the analytical results are shown in Table II. Clearly, all the lignin preparations contained rather low amounts of bound hemicelluloses as shown by the 2.2-8.0% neutral sugar content.…”

Effect of Adhesive Spreading Rate on the Performance of Laminated Compressed Oil Palm Trunks

“…The percentage weight loss was lower for the steam-pretreated samples as compared to that of non-steamed samples; the weight losses were 20% and 25%, respectively. The degradation of the samples corresponded to the thermal degradation of hemicellulose, water, and carbon dioxide (Sun et al 2001). The results indicated that the samples subjected to steaming prior to pressing possessed better thermal resistance and experienced lower weight loss after degradation as compared to the samples without steaming.…”