Chengxiang Li, Yue Wu, Chunhui Zhang^*, Yao Liu, Qixuan Lin, Junli Ren^*

Journal of Renewable Materials, Vol.11, No.6, pp. 2555-2574, 2023, DOI:10.32604/jrm.2023.026908

Abstract Hemicellulose and lignin are not reasonably utilized during the dissolved pulp preparation process. This work aimed to propose a process for the co-production of dissolving pulp, furfural, and lignin from eucalyptus. High-grade dissolving pulp was prepared from eucalyptus using a combination of extremely low acid (ELA) pretreatment, Kraft cooking, and elementary chlorine-free (ECF) bleaching. The obtained pre-hydrolysate was catalytic conversion into furfural in a biphasic system, and lignin during Kraft cooking and ECF was recovered. The process condition was discussed as well as the mass flow direction. The results showed that ELA pretreatment could effectively remove 80.1% hemicellulose. Compared with… More >

Antti Ojala^1,*, Lisa Wikström¹, Kalle Nättinen², Jani Lehmonen³, Karita Kinnunen-Raudaskoski⁴

Journal of Renewable Materials, Vol.2, No.4, pp. 278-284, 2014, DOI:10.7569/JRM.2014.634126

Abstract This article presents a new method of producing thermomoldable nonwoven materials based on kraft lignin (KL) and softwood kraft pulp (KP). A mixture of starch acetate (SA) and triethyl citrate (TEC) was used as a water insoluble plasticizer for KL. The thermoplastic lignin (TPL) material with the optimized ratio of KL, SA and TEC was prepared in a twin-screw extruder. The TPL compound was ground and mixed with KP fi bers to produce thermoformable sheets using foam-laid technology. The formed webs were compression molded (CM) into plates and mechanically tested. The foam-laid composites had tensile strengths and modulus of 67… More >

Silvia Helena Fuentes da Silva¹, Patricia Soares Bilhalva dos Santos², Darci Alberto Gatto³, Maria Angeles Andres¹, Itziar Egüés^1,*

Journal of Renewable Materials, Vol.7, No.6, pp. 527-534, 2019, DOI:10.32604/jrm.2019.04291

Abstract Kraft lignin was liquefied using polyethylene glycol #400 (PEG) and glycerol (G) in a weight ratio of 80/20 (w/w) and sulphuric acid (SA) as catalyst under atmospheric pressure at 160ºC. The three independent variables: reaction time (60, 80 and 100 min), percentage of lignin (15, 20 and 25%, w/w), and catalyst concentration (0, 3 and 6%, w/w), were varied resulting in 27 experimental runs. The effect of these reaction conditions on the properties of the polyols was evaluated. The statistical analysis showed that only “the percentage of lignin” did not influence the properties of the liquefied products, however, reaction time… More >

F.J. Santiago-Medina¹, M.C. Basso¹, A. Pizzi^1,2,*, L. Delmotte³

Journal of Renewable Materials, Vol.6, No.4, pp. 413-425, 2018, DOI:10.7569/JRM.2017.634172

Abstract The reaction of a desulphurized kraft lignin with hexamethylene diamine and dimethyl carbonate has allowed the development of isocyanate-free polyurethane resins. The present research work is based on previous studies made with hydrolyzable and condensed tannins, but takes advantage of the higher number of hydroxyl groups present in lignin and their different aliphatic and aromatic character. The obtained materials were analyzed by Fourier transform infrared (FTIR) spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and solid-state cross-polarization/magic angle spinning (CP MAS) 13 C nuclear magnetic resonance (NMR), which have revealed the presence of urethane functions. The interpretation of the… More >

A. M. Borrero-López¹, F. J. Santiago-Medina¹, C. Valencia^1,2*, M. E. Eugenio³, R. Martin-Sampedro³, J. M. Franco^1,2

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 out to evaluate the performance… More >

Mohamed Ammar¹, Ramzi Khiari^2,3,4*, Mohamed Naceur Belgacem^3,4*, Elimame Elaloui¹

Journal of Renewable Materials, Vol.5, No.2, pp. 116-123, 2017, DOI:10.7569/JRM.2016.634136

Abstract The present study investigated the preparation of biomatrices from Stipa tenacissima L. and its valorization for fiberboard application. Resins were produced by extracting lignin from the Stipa tenacissima L. black liquor by soda process and combining it with glyoxal as crosslinking agent to produce lignin-glyoxal-resin (LGR). The matrix was characterized by several methods, such as FTIR and ATG/ATD, and then mixed with date palm rachis as reinforcing fibers in different proportions of 30 and 50% (w/w with respect to the matrix) to produce biodegradable composite materials. Then, their thermal and mechanical properties were determined, using differential scanning calorimetry (DSC) and… More >