Arunjunairaj Mahendran^1*, Günter Wuzella¹, Thomas Hardt-Stremayr¹, Wolfgang Gindl-Altmutter²

Journal of Renewable Materials, Vol.4, No.3, pp. 215-224, 2016, DOI:10.7569/JRM.2016.634110

Abstract Woven natural fiber-reinforced composites were fabricated using four different flax fabrics and two biobased epoxy resin matrices. The reinforced composites were prepared using resin infusion technique and fiber volume fractions of between 28–35% were achieved using this method. The fiber matrix interaction and the failure mechanism in the composite were observed using scanning electron microscopy. The flexural strength and modulus on the warp and weft directions were characterized and it was found that based on yarn count and yarn thickness change in the flexural strength was observed. Dynamic water absorption and thickness swelling were observed More >

A. Sammaiah¹, K. V. Padmaja¹, K. I. Suresh^*,2, R. B. N. Prasad¹

Journal of Renewable Materials, Vol.4, No.2, pp. 113-122, 2016, DOI:10.7569/JRM.2015.634118

Abstract This article reports the effect of epoxidized jatropha oil (EJO) on the thermal, cure and viscoelastic properties of epoxy resins. Epoxidized jatropha oil with an oxirane value of 5.0 was prepared and epoxy formulations containing different concentrations of EJO were evaluated for cure, morphology, thermal and viscoelastic properties. The curing temperature of the formulations increased with increasing EJO content. The glass transition temperature of the cured films decreased from 56 °C for unmodified epoxy resin to 23 °C for the sample with 60 wt% EJO reactive diluent, suggesting good plasticizing action. The thermal decomposition was 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 More >

Pronob Gogoi, Dhaneswar Das, Shyamalima Sharma, Swapan K. Dolui^*

Journal of Renewable Materials, Vol.3, No.2, pp. 151-159, 2015, DOI:10.7569/JRM.2014.634129

Abstract Alkyd resins based on Jatropha curcas oil with different molar ratios of phthalic anhydride (PA) and maleic anhydride (MA) were prepared by alcoholysis followed by polyesterifi cation reaction. The progress of the reaction was traced by the determination of acid value at regular time intervals. From the kinetic study the extent of the reaction was found in the range of 52.4–61.2%. The prepared resins were blended with a commercially available fast-curing epoxy resin in order to improve the properties like curing time, chemical resistance, tensile strength, and thermal stability. The morphology study of the blends More >

William Eberts, Matthew T. Siniawski^*, Timothy Burdiak, Nick Polito

Journal of Renewable Materials, Vol.3, No.4, pp. 259-267, 2015, DOI:10.7569/JRM.2014.634137

Abstract Single-ply biocomposite laminates were fabricated with two different woven fabrics and a bio-based resin using a wet layup technique at room temperature. A highly elastic, stockinette weave bamboo fiber fabric and a thicker, inelastic plain weave bamboo fabric were both investigated. The elastic fabric was pre-strained at 25% intervals, ranging from 0–100% of its original length. Samples made with E-Glass and S-Glass, two common glass fiber reinforcements, were also fabricated using the bioresin as benchmarks. The ultimate strength and modulus of elasticity characteristics of the composites were determined using the ASTM D3039/ D3039M-08 standard test… 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 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 >

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 >

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 >

Arnaud Nicollin¹, Xinjun Li¹, Pierre Girods¹, Antonio Pizzi^1,2,*, Yann Rogaume¹

Journal of Renewable Materials, Vol.1, No.4, pp. 311-316, 2013, DOI:10.7569/JRM.2013.634124

Abstract Experimental investigations have been carried out on the potential use of tannin-furfuryl alcohol resin for biobased composites using vegetal fi ber reinforcement. Results showed that a mixture containing 54% furfuryl alcohol, 45% modifi ed quebracho extract and 0.9% paratoluenesulfonic acid as a catalyst yields a resin that can be used with a nonwoven fl ax fi ber mat to manufacture lightweight composites with good mechanical properties and a very short curing time with a regular hot press. The panels made were tested for tensile and fl exural modulus and strength, water resistance and thermo-degradation. More >