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

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 PF, and Tannin-Hexamine TH)… More > Graphic Abstract

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

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 forming a physically entangled network.… 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

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 and prodelphinidin units.… More >

Yui-Chuin Shiah^{1, *}, Sheng-Chi Huang¹, M. R. Hematiyan²

CMC-Computers, Materials & Continua, Vol.64, No.2, pp. 701-727, 2020, DOI:10.32604/cmc.2020.010417

Abstract In engineering practice, analysis of interfacial thermal stresses in composites is a crucial task for assuring structural integrity when sever environmental temperature changes under operations. In this article, the directly transformed boundary integrals presented previously for treating generally anisotropic thermoelasticity in two-dimension are fully regularized by a semi-analytical approach for modeling thin multi-layers of anisotropic/isotropic composites, subjected to general thermal loads with boundary conditions prescribed. In this process, an additional difficulty, not reported in the literature, arises due to rapid fluctuation of an integrand in the directly transformed boundary integral equation. In conventional analysis, thin adhesives are usually neglected due… More >

Xuedong Xi, Antonio Pizzi^*

Journal of Renewable Materials, Vol.8, No.7, pp. 715-725, 2020, DOI:10.32604/jrm.2020.010882

Abstract A three reagents adhesive system for wood particleboards not containing any aldehyde was developed by the reaction of glucose or sucrose with triacetin (glycerin triacetate) and with hexamethylene diamine. The system was found to be based on the mix of three reactions, namely the reaction of (i) glucose with triacetin, (ii) of the diamine with triacetin, and (iii) of glucose with the diamine. The chemical species formed were identified by Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-ToF) mass spectrometry. Wood particleboard panels were prepared with this adhesive system and gave good internal bond (IB) strength results suitable for… More >

Verónica L. Mucci¹, M. E. Victoria Hormaiztegui², Mirta I. Aranguren^1,*

Journal of Renewable Materials, Vol.8, No.6, pp. 579-601, 2020, DOI:10.32604/jrm.2020.09455

Abstract The increasing pressure from consumers and policy makers to reduce the use of synthetic polymers, whose production contributes to the depletion of non-renewable resources and are usually non- biodegradable, has prompted the efforts to find suitable bio-based sources for the production of polymers. Vegetable oils have been a frequently spotted in this search because they are versatile, highly available and a low cost liquid biosource, which can be used in the synthesis of a wide plethora of different polymers and reactive monomers. Following the same idea of reducing the environmental stress, the traditional polyurethanes that are soluble in organic solvents… More >

F.-J. Santiago-Medina¹, A. Pizzi^1,2,*, S. Abdalla²

Journal of Renewable Materials, Vol.5, No.5, pp. 435-447, 2017, DOI:10.7569/JRM.2017.634166

Abstract An adhesive based on the reaction of a very fast reacting procyanidin-type condensed tannin, namely purified pine bark tannin, with a biosourced nontoxic and nonvolatile aldehyde derived from the pulp and paper industry, namely hydroxymethylfurfural (HMF), was shown to almost satisfy the relevant standards for bonding wood particleboard. The conditions of pH used are determinant for the result. The oligomers obtained by the reaction and their distribution have been determined by matrix-assisted laser ionization desorption time-of-flight (MALDI-TOF) mass spectrometry. Of the two reactive groups of hydroxymethylfurfural capable of reacting, the furanic aldehyde one and the furanic hydroxymethyl alcohol group, only… More >

J. Mohan¹, D. Carolan¹, N. Murphy¹, A. Ivankovic¹, D. Dowling¹

Structural Durability & Health Monitoring, Vol.3, No.2, pp. 81-86, 2007, DOI:10.3970/sdhm.2007.003.081

Abstract The aim of this work is to investigate the influence of a variety of plasma treatments on the surface properties of an epoxy-based composite material and to establish a relationship between these properties and the subsequent mechanical behaviour of adhesively bonded joints. To this end, specimens were subjected to three different types of plasma treatment: two short treatments (2min) of He and He plus O₂, and one long treatment (15min) of He plus O₂. The variation in surface energy of the composite specimens was examined in each case over a period of up to 3 days using contact angle measurements.… More >

Flávio Pereira¹, João Pereira², Nádia Paiva³, João Ferra³, Jorge Manuel Martins^1,4, Fernão D. Magalhães¹, and Luísa Carvalho^1,4*

Journal of Renewable Materials, Vol.4, No.1, pp. 41-46, 2016, DOI:10.7569/JRM.2015.634128

Abstract This work studies the use of soy protein as a natural formaldehyde scavenger in wood particleboard production. The protein is incorporated in two forms: a) as a powder, during the blending process of wood particles with urea-formaldehyde binder resin, and b) as an aqueous solution, added at different times during resin synthesis. Analysis of variance (ANOVA) was used to evaluate the signifi cance level of two effects (amount of added soy and time of addition) on internal bond strength, thickness swelling, and formaldehyde content of the resulting panels. The results showed that soy protein can contribute to decrease the formaldehyde… More >