Saeed Kazemi Najafi¹, Farhood Najafi², Antonio Pizzi^3,*, Fatemeh Hassani Khorshidi^1,*, Rabi Behrooz¹

Journal of Renewable Materials, Vol.11, No.5, pp. 2171-2189, 2023, DOI:10.32604/jrm.2023.027835

Abstract Polyols are groups of organic compounds which contain carbon and are randomly linked to other atoms, especially carbon-carbon and carbon-hydrogen. These compounds are mainly used as reactants to make other polymers. Among biopolymers, lignin is regarded as the base of a new polymer in polyol construction. The present study aimed to investigate the effects of amine type (diethylenetriamine and ethylenediamine) on the modification of lignin-based polyols, so as to provide an alternative to petroleum polyols and, in turn, increase functional groups and reduce their harm to humans’ health and the environment. To this aim, first, lignin was extracted from raw… More > Graphic Abstract

Hamed Younesi-Kordkheili^1,*, Antonio Pizzi^2,*

Journal of Renewable Materials, Vol.11, No.5, pp. 2075-2083, 2023, DOI:10.32604/jrm.2023.026706

Abstract The influence of nanolignin coupling bio-agent on some characteristics of polypropylene-wood flour composites was studied. Thus, nanolignin was prepared by the acidic method, and then different ratios of it (0, 1, 3 and 5 wt%) were added to a polypropylene-wood flour mixture. After mechanically mixing wood flour, nanolignin, and polypropylene, the mixture was injection molded. ASTM methods were used to measure the structural properties of nanolignin, and prepared composites’ water absorption, thickness swelling, bending modulus, and bending, tensile and impact strengths. Transforming the original lignin to nanolignin did not change the chemical bonds of the material. The addition of nanolignin… More >

Penghui Li^1,2, Zhengwei Jiang², Chi Yang², Jianpeng Ren^1,2, Bo Jiang^1,2, Wenjuan Wu^1,2,*

Journal of Renewable Materials, Vol.11, No.5, pp. 2233-2248, 2023, DOI:10.32604/jrm.2023.025279

Abstract Lignin is a natural polymer, second only to cellulose in natural reserves. Degradation is one of the ways to achieve the high-value transformation of lignin. Deep eutectic solvent (DES) thermal degradation of lignin can be used as an excellent green degradation method. This paper introduces the degradation mechanism and effect of the lactic acid-choline chloride DES system in dissolving and degrading alkaline lignin, and the final solvent recovery. It can also be found from the scanning electron microscope (SEM) images that the surface of the degraded solid product is transformed from smooth to disordered. Fourier transform infrared (FTIR) spectroscopy and… More > Graphic Abstract

Chao Wang, Xuezhen Feng, Wanbing Li, Shibin Shang^*, Haibo Zhang^*

Journal of Renewable Materials, Vol.11, No.4, pp. 1793-1805, 2023, DOI:10.32604/jrm.2023.024521

Abstract Due to the low content of adsorption-active groups in lignin, its application in the field of adsorption is limited. Herein, we first prepared cationic kraft lignin acrylate, from which a cationic lignin (CKLA) hydrogel was further prepared by cationic kraft lignin acrylate, acrylamide, and N, N’-methylenebisacrylamide. The morphology, compression properties and swelling properties of CKLA hydrogels were investigated. The prepared CKLA hydrogel was applied as an adsorbent for Congo red. The effect of CKLA hydrogel dosages, initial concentration of Congo red, and pH on adsorption efficiency was investigated. The maximum Congo red removal efficiency was obtained at the initial concentration… More >

Lijing Huang, Penghui Li, Kangjie Jiang, Wenjuan Wu^*

Journal of Renewable Materials, Vol.11, No.4, pp. 1613-1626, 2023, DOI:10.32604/jrm.2022.023605

Abstract The effect of lignin structural units on enzymatic hydrolysis of lignocellulosic biomass was investigated, especially the inhibitory role of lignin in non-productive adsorption with enzymes. Milled wood lignin (MWL) was isolated from different hardwoods of poplar, eucalyptus and acacia. The isolated lignin samples were characterized by elemental analysis, gel permeation chromatography, nitrobenzene oxidation and fourier infrared spectroscopy. The mechanism of lignin structural units on enzymatic hydrolysis of cellulose was studied by quartz crystal microbalance (QCM). The results showed that different structural units of lignin had different adsorption capacity for enzymes. The results of nitrobenzene oxidation indicated that the S/G ratio… More > Graphic Abstract

Yunxia Zhou¹, Hisham Essawy², Ai Liu¹, Chenyu Yang¹, Defa Hou¹, Xiaojian Zhou^1,*, Guanben Du¹, Jun Zhang^1,*

Journal of Renewable Materials, Vol.11, No.2, pp. 837-852, 2023, DOI:10.32604/jrm.2022.022792

Abstract This study presents an easily prepared film based on alkaline starch-polyvinyl alcohol hybrid and lignin fiber as an additive (SPL film). The SPL film was prepared under acidic conditions through a polycondensation reaction of PVA and a mixture incorporating alkaline starch and lignin fiber from agriculture or forest source. The examination using scanning electron microscopy (SEM) showed that the surface of SPL film was smooth and the lignin fiber had good compatibility within the film hybrid. Electrospray ionization mass spectroscopy (ESI-MS) and fourier transform infrared (FTIR) investigations indicated that alkaline starch and lignin fiber reacted with PVA under acidic conditions… More > Graphic Abstract

Tanhao Zhang, Shuo Zhang, Wu Lan^*, Fengxia Yue^*

Journal of Renewable Materials, Vol.11, No.2, pp. 555-566, 2023, DOI:10.32604/jrm.2023.025701

Abstract Ferulic acid (FA) and p-coumaric acid (pCA) in bagasse, wheat straw, corn straw, and corncob were extracted by alkaline hydrolysis and characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). It was found that the FA and most of the pCA in gramineous biomass could be dissociated and released after being treated with 1 M NaOH at 100°C for 4 h. The yields of pCA/FA in bagasse, wheat straw, corn straw, and corncob determined by GC-FID are 39.8/11.5, 13.7/11.0, 28.0/11.0, and 35.1/14.5 mg/g, respectively. The raw materials and the treated solid residues were characterized by gel-state 2D Heteronuclear Single… More > Graphic Abstract

Sinto Jacob¹, Manjusri Misra^1,2, Amar Mohanty^1,2,*

Journal of Renewable Materials, Vol.1, No.2, pp. 154-165, 2013, DOI:10.7569/JRM.2012.634107

Abstract This study investigated the use of potassium persulfate (KPS) as an initiator for the grafting of methyl methacrylate (MMA) onto softwood kraft lignin. Ammonium iron (II) sulfate hexahydrate was used as a catalyst to overcome the inherent inhibition of lignin to free radical grafting and to make lignin copolymer under mild conditions using an aqueous medium. The infl uence of temperature, initiator concentration, time of reaction and monomer concentration on percentage of grafting were studied. A maximum of 31% grafting was achieved at 55ο C. Graft copolymer was identifi ed from the Fourier transform infrared (FTIR) spectrum by the new… More >

Hyoe Hatakeyama^1,*, Tatsuko Hatakeyama²

Journal of Renewable Materials, Vol.1, No.2, pp. 113-123, 2013, DOI:10.7569/JRM.2012.634111

Abstract Lignin and saccharides are two major components of plants. Huge amounts of plant residues are obtained as by-products of large-scale industries, such as pulp and paper, bio-fuel and the food industry. In this paper, preparation of polyurethane (PU) foam directly from various kinds of industrial lignin and molasses, which have scarcely been utilized, is summarized based on our results obtained by recent investigation. A onestep reaction using hydroxyl groups of plant materials as an active site makes it possible to produce a wide variety of PU, such as foams, sheets, gels and composite matrix. In this paper, PU foams receive… 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 >