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David Grewell^1,*, Gowrishankar Srinivasan¹, Eric Cochran²
Journal of Renewable Materials, Vol.2, No.3, pp. 157-165, 2014, DOI:10.7569/JRM.2014.634112
Abstract Presented in this study is a novel recycling strategy for poly(lactic acid) (PLA) in which the depolymerization is rapidly promoted by the base-catalyzed hydrol-/alcohol-ysis of the terminal ester bonds under mild conditions. Post-consumer PLA water bottles were cut into approximately 6 x 2 mm plastic chips and heated to 50–60o C in water, ethanol, or methanol as the depolymerization medium. A variety of carbonate salts and alkaline metal oxides were screened as potential catalysts. High-power ultrasound was also investigated as a means to accelerate the PLA decomposition. Both mass loss and HPLC analysis of the treated suspensions showed that the… More >

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Richard C. Ferguson, Sharathkumar K. Mendon, James W. Rawlins^*, Shelby F. Thames
Journal of Renewable Materials, Vol.2, No.3, pp. 166-172, 2014, DOI:10.7569/JRM.2013.634133
Abstract Commercial particleboards are currently synthesized by blending wood furnish with formaldehyde-based resins and curing them under a combination of heat and pressure. Particleboards manufactured with urea-formaldehyde resin are known to liberate formaldehyde during their service lives. Formaldehyde’s carcinogenicity has prompted the search for environmentally-friendly resins for wood composite manufacture. Soybean protein-based adhesives have been developed as a renewable and formaldehyde-free replacement for urea-formaldehyde resins. Particleboards processed using the soybean protein adhesive matched or exceeded performance criteria of M-2-grade commercial particleboards when evaluated as per American National Standards Institute (ANSI) specifi cations. More >

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A. Sauget^1,*, X. Zhou¹, A. Pizzi^1,2
Journal of Renewable Materials, Vol.2, No.3, pp. 173-181, 2014, DOI:10.7569/JRM.2013.634128
Abstract Tannin-resorcinol-formaldehyde (TRF) resin shows a good compatibility with natural fl ax fi bers and yields composite materials of good mechanical properties when using paraformaldehyde as a hardener. Different formulations, curing parameters and processes such as high-temperature curing in press or spray-drying have been explored in order to adapt this resin to composite manufacturing and to improve the properties of this new material. Additional testing has been performed on the TRF resin by thermomechanical analysis to observe its reactivity at different pH and with the use of different hardeners. More >

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M.C. Basso^1,2, S. Giovando³, A. Pizzi^2,4,*, M.C. Lagel^2,3, A. Celzard⁵
Journal of Renewable Materials, Vol.2, No.3, pp. 182-185, 2014, DOI:10.7569/JRM.2013.634137
Abstract Condensed fl avonoid tannin foams were obtained under alkaline conditions. This entailed the elimination of furfuryl alcohol from these formulations, as under alkaline conditions, foam preparation could not rely on the heat generated by the self-condensation of furfuryl alcohol, which occurs only under strongly acidic conditions. The approach used to formulate the alkaline foam was: (i) the total elimination of furfuryl alcohol from the formulation, (ii) coupled with the use of an aldehyde hardener different from formaldehyde (for environmental reasons) and (iii) the application of moderate heat to allow foaming. These were not tannin/ furanic foams as their acid-curing counterparts,… More >

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A. Sauget^1,*, X. Zhou¹, A. Pizzi^1,2
Journal of Renewable Materials, Vol.2, No.3, pp. 186-200, 2014, DOI:10.7569/JRM.2013.634138
Abstract Glyoxal and glutaraldehyde are two viable alternatives to formaldehyde for the preparation of tanninresorcinol-aldehyde adhesive but lead to less resistant glue joint. Tannin-resorcinol-glyoxal (TRG1) and tannin-resorcinol-glutaraldehyde (TRG2) resins have been prepared and analyzed by matrix-assisted laser desorption/ionization time of fl ight (MALDI-ToF) spectrometry to understand the chemical process behind the pre-curing of these resins and possibly the causes of this lower resistance. The analysis showed that TRG resins are not a simple mix of resorcinol-aldehydes oligomers and fl avonoids, but a much more complex combination of various species including tannin-aldehydes and tannin-resorcinol oligomers. More >

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V. K. Srivastava¹, A. Pizzi^2,3,*
Journal of Renewable Materials, Vol.2, No.3, pp. 201-206, 2014, DOI:10.7569/JRM.2014.634107
Abstract Fine wood powder/furanic foams were prepared with a strong predominance of the wood component. Low weight and density are important properties of foamed composites. Focusing on preparing light materials, wood foam composites were made using a chemical foaming method and expanded using diethyl ether as the foaming agent. The additives were added to note their effect on the density and mechanical properties, like impact strength and Young’s moduli, of the expanded composites. Various tests and scanning electron microscopy analysis were also performed. The foaming agent resulted in closed cells with varied sizes and more or less regular shapes, and with… More >

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M.C. Lagel^1,*, A. Pizzi^1,2, S. Giovando³
Journal of Renewable Materials, Vol.2, No.3, pp. 207-219, 2014, DOI:10.7569/JRM.2014.634111
Abstract Natural hydrolysable chestnut tannin extracts used to partially substitute phenol in Phenol-Formaldehyde (PF) resins for phenolic rigid foams were analysed by matrix-assisted desorption ionization time of fl ight (MALDI-TOF) mass spectrometry. PF only, chestnut only and PF-chestnut copolymerised oligomer types and distribution were determined. MALDI-TOF analyses of a PF control resin (with the same molar ratio) and of chestnut tannin extracts were performed in order to identify the peaks of molecular weights corresponding to copolymers of chestnut tannins with phenol and formaldehyde. More >

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M.C. Lagel¹, A. Pizzi^1,2, S. Giovando³, A. Celzard⁴
Journal of Renewable Materials, Vol.2, No.3, pp. 220-229, 2014, DOI:10.7569/JRM.2014.634113
Abstract With the depletion of fossil resources, tannin extracts can be a natural alternative to some synthetic products. Hydrolysable chestnut tannin extracts have been used to partially replace phenol in PF resins for phenolic rigid foams. Phenol-formaldehyde-chestnut tannin (PFT) phenolic foams were initially made from copolymerized PFT resins of different molar ratio. The PFT foams so prepared were tested for thermal conductivity, these being slightly worse than that of pure PF foams; and for mechanical and water absorption, these two properties being better than those of pure PF foams. Indeed, PF resins represent an important part of synthetic resins. They are… More >

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A. Pizzi^1,2,*, C. Zollfrank³, X. Li¹, M. Cangemi¹, A. Celzard⁴
Journal of Renewable Materials, Vol.2, No.3, pp. 230-234, 2014, DOI:10.7569/JRM.2014.634114
Abstract Protein rigid foams based on albumin coreacted with camphor and an aldehyde were converted into silicon carbide (SiC) foams. This was carried out by putting albumin-derived template foams in contact with silicon compounds in liquid phase and calcinating the mix obtained at a relatively low temperature of 500°C to eliminate the protein and leave the SiC foam. The transformation was followed by scanning electron microscopy (SEM) from the natural albumin foams to the gel obtained by infi ltrating them with tetraethyl orthosilicate (TEOS) and to the appearance of the SiC foams after calcination. X-ray diffraction (XRD) and Raman spectra were… More >

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Dinesh Balgude, Anagha Sabnis^*
Journal of Renewable Materials, Vol.2, No.3, pp. 235-245, 2014, DOI:10.7569/JRM.2014.634115
Abstract Renewable resource-based hybrid crosslinker was successfully synthesized via sol-gel technology. The synthesis involved malenization of Cashew Nut Shell Liquid (CNSL) followed by its silane modifi cation and subsequent hydrolysis and condensation with tetraethyl orthosilicate (TEOS). The synthesized crosslinker was characterized by spectroscopic analysis (FT-IR, ¹ H-NMR, ¹³C-NMR and ²⁹Si-NMR) for structural elucidation. The crosslinker was further formulated in a conventional stoving system. Fully-cured coatings were obtained after stoving at 120°C for ½ hr and were then evaluated for physical, mechanical, chemical, optical, accelerated weathering, electrochemical and morphological properties. The incorporation of hybrid crosslinker in a conventional stoving system was observed… More >

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