DHARMESH B. SANKHAVARA, JALPA V. CHOPDA, JIGNESH P. PATEL, PARSOTAM H. PARSANIA^*

Journal of Polymer Materials, Vol.38, No.1-2, pp. 11-19, 2021, DOI:10.32381/JPM.2021.38.1-2.2

Abstract The curing of epoxy resin of (2E, 6E)-2,6-bis(4-hydroxy benzylidene) cyclohexanone (EBHBC) was carried out at four different heating rates in the nitrogen atmosphere by using 4,4’-diamino diphenylmethane (DDM), 4,4’-diamino diphenyl sulfone (DDS), and 1,2,3,6-tetrahydrophthalic anhydride (THPA) as hardeners. From DSC curves onset, peak exotherm and end set temperatures, as well as heat release, were derived. The energy of activation was derived following Kissinger and Ozawa methods. Observed trend in Ea is EBHBC-THPA > EBHBCDDS > EBHBC-DDM > EBHBC. Nature and chemical structure of the hardeners affected the curing of EBHBC. More >

Zhigang Wu^1,#, Sicheng Chen^1,#, Jiankun Liang², Lifen Li¹, Xuedong Xi^3,4, Xue Deng¹, Bengang Zhang^3,*, Hong Lei^4,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1959-1972, 2021, DOI:10.32604/jrm.2021.016786 - 04 June 2021

Abstract Alkali lignin was processed by plasma and then used in modification of phenol formaldehyde resin in this study. Chemical structural changes of lignin which was processed by plasma as well as bonding strength, tensile property, curing performance and thermal property of the prepared phenol formaldehyde resin which was modified by the plasma processed lignin were analyzed. Results demonstrated that: (1) Alkali lignin was degraded after the plasma processing. The original groups were destroyed, and the aromatic rings collected abundant free radicals and oxygen-containing functional groups like hydroxyls, carbonyls, carboxyls and acyls were introduced into increase… More > Graphic Abstract

Syed Waheedullah Ghori^1,*, G. Srinivasa Rao²

Journal of Renewable Materials, Vol.9, No.7, pp. 1283-1292, 2021, DOI:10.32604/jrm.2021.014987 - 18 March 2021

Abstract Date palm fiber (DPF) and kenaf fiber were reinforced in epoxy having various fiber loading 40%, 50%, and 60% by weight. These hybrid samples were manufactured by hot press technique and then characterized for tensile, impact, and morphological behavior to evaluate the ratio of fibers in the hybrid composites; the addition of kenaf improved the tensile properties, Scanning Electron Microscopy (SEM) revealed the interfacial bonding of fiber/matrix, and dispersion and void content in composites. Impact test studies reflected the effect of natural fiber with epoxy, level of stress transfer from matrix to reinforced material, and More > Graphic Abstract

Yan Song^1,2, Zhixin Wang³, Xin Zhang⁴, Rong Zhang¹, Jinchun Li^1,2,*

Journal of Renewable Materials, Vol.9, No.5, pp. 943-957, 2021, DOI:10.32604/jrm.2021.014131 - 20 February 2021

Abstract Lignin is a natural biopolymer with a complex three-dimensional network, commercially obtained from waste liquid of paper pulp and bioethanol production, and could be a candidate for preparation of environment-friendly bio-based polyphenol material. In the present work, the demethylated wheat straw alkali lignin (D-Lig), prepared by demethylation of wheat straw alkali lignin (Lig) using an in-situ generated Lewis acid, was used to synthesize bio-based phenol formaldehyde resin adhesive (D-LPF) applied in plywood. Effects of synthetic process’s factors, including lignin substitution for phenol, NaOH concentration and molar ratio of formaldehyde to phenol, on the bonding strength and… More >

Achille Gnassiri Wedaïna^1,2, Antonio Pizzi², Wolfgang Nzie¹, Raidandi Danwe³, Noel Konaï^4,*, Siham Amirou², Cesar Segovia⁵, Raphaël Kueny⁵

Journal of Renewable Materials, Vol.9, No.3, pp. 477-493, 2021, DOI:10.32604/jrm.2021.012782 - 14 January 2021

Abstract The Piptadeniastrum Africanum bark tannin extract was characterized using MALDI TOF, ATR-FT MIR. It was used in the development of a resin with Vachellia nilotica extract as a biohardener. This tannin is consisting of Catechin, Quercetin, Chalcone, Gallocatechin, Epigallocatechin gallate, Epicatechin gallate. The gel time of the resin at natural pH (pH = 5.4) is 660 s and its MOE obtained by thermomechanical analysis is 3909 MPa. The tenacity of Urena lobata fibers were tested, woven into unidirectional mats (UD), and used as reinforcement in the development of biocomposite. The fibers tenacity at 20, 30 and 50 mm More >

Medjda Amari¹, Kamel Khimeche^1,*, Abdelkader Hima² , Redouane Chebout³, Abderahmane Mezroua¹

Journal of Renewable Materials, Vol.9, No.3, pp. 463-475, 2021, DOI:10.32604/jrm.2021.013680 - 14 January 2021

Abstract Recently, the exploitation of renewable plant resources in the formulation of adhesives is very promising for their availability at low coast, as well as their richness in biomolecules such as polyphenols. In this way, many research studies tannins extracted from different sources such as mimosa, quebracho, and pine have been the subject of very satisfactory recent studies. In this paper, a new complete characterization of the tannins extracted from the bark of eucalyptus globulus harvested from two regions in Algeria was achieved. The structural characterization enabled us to confirm the richness in condensed tannins, particularly in procyanidin More >

Dafni Foti¹, Costas Passialis¹, Elias Voulgaridis¹, Stergios Adamopoulos^2,*

Journal of Renewable Materials, Vol.9, No.1, pp. 85-96, 2021, DOI:10.32604/jrm.2021.011868 - 30 November 2020

Abstract Recycled polystyrene in combination with paraffin wax, alkyd resin, and gum rosin were used as components in formulations to investigate their water repellency when applied to cellulosic filter paper substrates. Polystyrene was used in concentration of 5, 10, 15 and 20%, alkyd resin and gum rosin of 5% each and paraffin wax of 0.5%. Totally, twenty four water repellent solutions were prepared. Water repellency was evaluated in terms of water absorption of the cellulosic fibrous mats. The relations between retention of solid substances of the formulations and grammage and water absorption of filter paper samples… More >

ANIL KUMAR VEERAPANENI¹, CHANDRASEKAR KUPPAN^2,*, MURTHY CHAVALI^3,*

Journal of Polymer Materials, Vol.37, No.3-4, pp. 121-130, 2020, DOI:10.32381/JPM.2020.37.3-4.1

Abstract The mechanical properties of hybrid nanocomposites made of epoxy/glass fibre dispersed with nano-α-Al₂ O₃ powder at different weight percentages were studied.The effect of nano-α- Al₂O₃ size and wt% on mechanical properties like tensile, flexural, interlaminar shear stress and hardness enhanced because of their higher surface area and interfacial polymer-metal interaction. The nanoparticle embedded laminates have shown improvement in flexural strength,and hardness when compared to laminate without nano-α-Al₂ O₃. The properties varied with the loading and size of the nanoparticles. The tensile strength was highest for 0.5 wt% of 200nm nano-α-Al₂O₃, which is 167.80 N/m₂.The highest flexural strength was observed More >

Wendong Feng^1,2, Jian Li², Hongxiang An², Yunhai Wang^1,*

Journal of Renewable Materials, Vol.8, No.10, pp. 1283-1293, 2020, DOI:10.32604/jrm.2020.011000 - 31 August 2020

Abstract Spent IERs are released during the operation and decommissioning of nuclear facilities. The safe and efficient treatment of spent IERs is an emergent problem in nuclear industry. IRN77 is a typical ion exchange resin widely used in many nuclear power plants. Fenton process can degrade organic resins and reduce the radioactive residues volume and the disposal cost significantly. In this work, the IRN77 resin was selected as a model ion exchange resin and its treatment via Fenton process was investigated. The influencing factors for resin degradation, including catalyst dosage, reaction time, initial pH, temperature and… More >

Marion Thébault¹, Ya Li¹, Christopher Beuc¹, Stephan Frömel-Frybort^1,2, Edith-Martha Zikulnig-Rusch¹, Larysa Kutuzova³, Andreas Kandelbauer^3,*

Journal of Renewable Materials, Vol.8, No.10, pp. 1181-1198, 2020, DOI:10.32604/jrm.2020.09755 - 31 August 2020

Abstract High Pressure Laminates (HPL) panels consist of stacks of self-gluing paper sheets soaked with phenol-formaldehyde (PF) resins. An important requirement for such PFs is that they must rapidly penetrate and saturate the paper pores. Partially substituting phenol with bio-based phenolic chemicals like lignin changes the physico-chemical properties of the resin and affects its ability to penetrate the paper. In this study, PF formulations containing different proportions of lignosulfonate and kraft lignin were used to prepare paper-based laminates. The penetration of a Kraft paper sheet was characterized by a recently introduced, new device measuring the conductivity… More >