Jaša Saražin¹, Ida Poljanšek¹, Antonio Pizzi², Milan Šernek^1,*

Journal of Renewable Materials, Vol.10, No.8, pp. 2117-2131, 2022, DOI:10.32604/jrm.2022.019602 - 25 April 2022

Abstract The curing process of two biobased adhesives: pine tanninhexamine (TH) and organosolv lignin non-isocyanate polyurethane (NIPU), suitable for interior nonstructural use, were compared with commercial urea-formaldehyde (UF) adhesive. Changes in chemical structure before and after the curing process were observed with Fouriertransform infrared spectroscopy (FTIR). The process of adhesive curing was monitored with differential scanning calorimetry (DSC) and the automated bonding evaluation system (ABES). Both DSC and ABES measurements confirmed UF as the fastest and NIPU as the slowest curing adhesive observed. Taking into account the ABES results, the optimal pressing parameters for the TH… More >

Yinhuan Yang^1,*, Manfeng Gong¹, Xiaoqun Xia¹, Linzhi Wu^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.1, pp. 365-378, 2022, DOI:10.32604/cmes.2022.018535 - 24 January 2022

Abstract The mechanical properties of Z-pins reinforced composites adhesively bonded single-lap joints (SLJs) under un-directional tension loading are investigated by experimental and numerical methods. Three kinds of joint configurations, including SLJs with three/two rows of Z-pins and “I” array of Z-pins, are investigated by tension test. The failure modes and mechanism of reinforced joints with different Z-pins numbers and alignment are analyzed, and the comparison is performed for the failure strengths of no Z-pins and Z-pins reinforced joints. According to experimental results, failure modes of three kinds of joints are all mixed failure. It turns out More >

Ke Shi^1,2, Luyang Wang^1,2, Ruige Qi^1,2, Chunxia He^1,2,*

Journal of Renewable Materials, Vol.10, No.5, pp. 1257-1268, 2022, DOI:10.32604/jrm.2022.017891 - 22 December 2021

Abstract This work was aim to prepare a packing material from natural resources to reduce the environment pollution caused by plastics. Four bio-adhesives (guar gum, sodium alginate, agar and chitosan) were combined with lotus leaf fibers to prepare degradable composites, respectively. The mechanical properties, moisture absorption profiles and the thermal conductivity of the composites were studied and the cross section morphology and the thermal properties of the composites were analyzed. The Fourier-transform infrared spectroscopy (FTIR) results showed that the polar groups such as –OH and –COO^– in bio-adhesives can form hydrogen bond with –OH in lotus leaf More >

Saad Nader^1,2, Felipe Guzman³, Raphael Becar¹, César Segovia⁴, Cecilia Fuentealba³, Miguel Peirera³, Evelyne Mauret², Nicolas Brosse^1,*

Journal of Renewable Materials, Vol.10, No.2, pp. 263-271, 2022, DOI:10.32604/jrm.2022.017923 - 30 August 2021

Abstract The reinforcing impact of Lignocellulosic micro and nanofibrillated cellulose (L-MNFCs) obtained from Eucalyptus Globulus bark in Urea-Formaldehyde UF adhesive was tested. L-MNFCs were prepared by an environmentally friendly, low-cost process using a combination process involving steam explosion followed by refining and ultra-fine grinding. Obtained L-MNFCs showed a web-like morphology with some aggregates and lignin nanodroplets. They present a mixture of residual fibers and fine elements with a width varying between 5 nm to 20 μm, respectively. The effects of the addition of low amounts of L-MNFCs (1% wt.) on the properties of three different adhesives (Urea-Formaldehyde UF, Phenol-Formaldehyde More > Graphic Abstract

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

Jianchao Deng^1,2, Haiying Zhou², Fuming Chen², Shuangbao Zhang^1,*, Ge Wang^2,*

Journal of Renewable Materials, Vol.9, No.9, pp. 1555-1570, 2021, DOI:10.32604/jrm.2021.015461 - 23 April 2021

Abstract Elementary units “bamboo bundle” and “bamboo sliver” were processed and cross-linked as “bamboo-bundle veneer (BBV)” and “bamboo-sliver veneer (BSV)” for preparation of laminated composites. The concept of “high-content-adhesive surface treatment” was raised to improve boards’ performance, rather than increasing adhesive absorption of every layer’s porous unit. That is, some BBVs experienced an extra “dipping & drying” to absorb more resin (named “HBBV”). The effect of the amount of knitting threads was also discussed for influencing BBV’s quality. Results indicated that light transmittance of BBVs decreased as the amount of threads added from 3 to 8,… More >

Xinyi Chen^1,2, Antonio Pizzi^1,*, Xuedong Xi^1,2, Xiaojian Zhou², Emmanuel Fredon¹, Christine Gerardin³

Journal of Renewable Materials, Vol.9, No.6, pp. 1045-1057, 2021, DOI:10.32604/jrm.2021.015066 - 11 March 2021

Abstract Soy-protein isolate (SPI) was used to prepare non-isocyanate polyurethane (NIPU) thermosetting adhesives for wood panels by reacting it with dimethyl carbonate (DMC) and hexamethylene diamine. Both linear as well as branched oligomers were obtained and identified, indicating how such oligomer structures could further cross-link to form a hardened network. Unusual structures were observed, namely carbamic acid-derived urethane linkages coupled with lactam structures. The curing of the adhesive was followed by thermomechanical analysis (TMA). It appeared to follow a two stages process: First, at a lower temperature (maximum 130°C), the growth of linear oligomers occurred, finally… More >

Xiaojian Chen¹, Wenrui Yao¹, Feifei Gao¹, Dingyuan Zheng¹, Qiong Wang³, Jun Cao^2,*, Haiyan Tan¹, Yanhua Zhang^1,2,*

Journal of Renewable Materials, Vol.9, No.5, pp. 979-992, 2021, DOI:10.32604/jrm.2021.014751 - 20 February 2021

Abstract The morphology and properties of corn starch and cassava starch were compared by SEM, DSC and TGA. The effects of amylose and amylopectin content on starch properties were studied by FT-IR, XRD and XPS. The plywood was pressed with the prepared adhesive and the bonding strength of the plywood was tested to analyze the difference among the adhesives from different plant sources and the difference after blending PAPI prepolymer. FT-IR results showed that the hydroxyl peak of cassava starch was stronger and wider. TGA showed that the residue of cassava starch was lower, but the More >

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 >

Jaša Saražin¹, Antonio Pizzi², Siham Amirou², Detlef Schmiedl³, Milan Šernek^1,*

Journal of Renewable Materials, Vol.9, No.5, pp. 881-907, 2021, DOI:10.32604/jrm.2021.015047 - 20 February 2021

Abstract A non-isocyanate-based polyurethane (NIPU) wood adhesive was produced from organosolv lignin, which is a bio-sourced raw material, available in large quantities and produced as a by-product of the paper industry. The formulation of this new lignin-based NIPU adhesive, which is presented, was chemically characterised by Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI ToF) mass spectrometry and by Fourier Transform Infra-Red (FTIR) spectrometry analyses. The oligomers formed were determined and showed that the three species involved in the NIPU adhesive preparation were formed by the co-reaction of the three reagents used: lignin, dimethyl carbonate, and… More >