B. BRAILSON MANSINGH¹, K. L. NARASIMHAMU², K. C. VARAPRASAD³, J. S. BINOJ^4,*, A. RADHAKRISHNAN⁵, ALAMRY ALI⁶

Journal of Polymer Materials, Vol.40, No.1-2, pp. 71-82, 2023, DOI:10.32381/JPM.2023.40.1-2.6

Abstract Several agro-wastes are rich in natural fibers and finds scope to be used as reinforcement in composite industry. These natural fibers have some advantages over man-made fibers, including low cost, light weight, renewable nature, high specific strength and modulus, and availability in various forms worldwide. In this paper, the effect of surface modification of leaf sheath coconut fiber (LSF) (an agro-waste) reinforced in phenol formaldehyde matrix composites with silicon carbide (SiC) nano particles as filler material were investigated for its mechanical characteristics. The investigation portrays that coconut LSF (CLSF) modified with potassium permanganate reinforced polymer composite with SiC nano particles… More >

Bengang Zhang^1,*, Antonio Pizzi^2,*, Mathieu Petrissans¹, Anelie Petrissans¹, Baptiste Colin¹

Journal of Renewable Materials, Vol.11, No.11, pp. 3867-3889, 2023, DOI:10.32604/jrm.2023.028888

Abstract Melamine-dialdehyde starch resins used for wood surface finishes have been developed. The reaction of melamine with dialdehyde starch has been shown to occur by FTIR and MALDI ToF spectrometry, with several oligomer species due to the reaction of the two materials being identified, and the resin thermal stability was studied by thermogravimetric analysis. The resins were prepared by two different procedures when it was realized that dialdehyde starch is sensitive to too high a temperature for prolonged times. The melamine-dialdehyde starch resins were applied on particleboard supports as a direct liquid surface finish and a resin-impregnated paper. The surface finishes… More >

Yuhui Huang¹, Zhiyuan Yin^1,2, Ming Liu¹, Meng Li¹, Yingfeng Zuo¹, Yan Qing¹, Yiqiang Wu^1,*

Journal of Renewable Materials, Vol.11, No.9, pp. 3417-3431, 2023, DOI:10.32604/jrm.2023.028511

Abstract The poor bonding performance between aqueous adhesives represented by melamine-urea formaldehyde (MUF) resins and reed straw hinders their applications in the field of non-wood-based panels. Multi-hydroxyl polymers are highly reactive and are often used as crosslinkers. This study fabricated a resin with a strengthened cross-linked structure by combining a multi-hydroxyl polymer and MUF resin prepolymer. The reed particleboard was prepared by using this resin as an adhesive and reed stalk as the matrix. The results show that neighboring molecules combined to form C–O–C bonds that strengthened the cross-linked structure of the resin. In addition, the viscosity of the resin was… More >

Guobing Xiong¹, Lu Hong², Zehui Ju³, Xiaoning Lu^3,*, Juwan Jin^3,*

Journal of Renewable Materials, Vol.11, No.9, pp. 3447-3461, 2023, DOI:10.32604/jrm.2023.027430

Abstract The study characterized the curing behaviors of phenol formaldehyde (PF) resin under different vacuum degrees and explored the properties of 9-ply plywood panels hot-pressed under both vacuum and atmospheric conditions. The changes in core temperature and moisture content of the plywood mats during hot pressing were investigated as well. It was found that the gel times and gel temperatures of PF resin decreased with the increase of vacuum degree using a self-made device. FTIR spectra indicated the degree of polycondensation of hydroxymethyl gradually increased with the increase in temperature. It was also observed that a higher degree of vacuum led… More >

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 >

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 >

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 >

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 >

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 >

X. Li¹, A. Pizzi^1,2,*, X. Zhou^3,*, V. Fierro⁴, A. Celzard⁴

Journal of Renewable Materials, Vol.3, No.2, pp. 142-150, 2015, DOI:10.7569/JRM.2014.634117

Abstract Tannin/furanic foams, typically 95% composed of materials of natural origin such as prorobinetinidin/ profi setinidin tannins and furfuryl alcohol, are potential alternatives to oil-based synthetic foams such as phenol-formaldehyde, and polyurethane foams. This article describes the development of second generation tannin/furanic foams, which are not only formaldehyde free, but also use nonvolatile, nontoxic aldehydes. Both glyoxal and glutaraldehyde were tried to substitute formaldehyde in tannin/furanic foams. The physical properties of these new foams are described and discussed. It was found that glutaraldehyde can totally substitute formaldehyde during tannin/furanic foam preparation, but that glyoxal cannot. The optimized proportion to prepare such… More >