Piotr Rojek², Mirta I. Aranguren¹, Aleksander Prociak², Mirna A. Mosiewicki^1*

Journal of Renewable Materials, Vol.4, No.4, pp. 266-274, 2016, DOI:10.7569/JRM.2016.634113

Abstract Solid biobased polyurethanes (PUs) were prepared from a rapeseed oil-based polyol (ROPO) synthesized by epoxidation reaction followed by oxirane ring-opening with diethylene glycol. The reference material was modified by replacement of the ROPO with glycerol in different proportions and also by addition of commercial microcellulose (MC). The curing process of the reactive mixtures was monitored by rheological measurements and the analysis showed that both MC and glycerol increase the time of crossover between storage and loss modulus (liquid to solid transition in the response at 1 Hz). The completely cured polyurethanes were characterized by physical, morphological and mechanical analysis. The… More >

Juan P. Correa^1,2*, Alejandro Bacigalupe^2,3, Jorge Maggi⁴, Patricia Eisenberg^2,3

Journal of Renewable Materials, Vol.4, No.4, pp. 258-265, 2016, DOI:10.7569/JRM.2016.634117

Abstract Poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT)-based nanocomposites were prepared by melt blending of PLA and PBAT with 5 wt% of unmodified (Cloisite Na) and modified (Cloisite 30B) montmorillonites. X-ray diffraction (XRD) revealed an intercalated structure in both nanocomposites. The extent of the intercalation was higher for nanocomposites based on modified clays (OMMT) with chemical affinity with the polymer matrix. Rheological measurements have shown an increase in viscosity and a better degree of clay dispersion for nanocomposites containing OMMT. Nanocomposites with OMMT showed lower PBAT separated phase particle size and improvements in thermal stability, mechanical properties and water vapor barrier when compared with… More >

M. L. Lambri^1,2, E. D. Giordano^2,3, P. B. Bozzano⁴, F. G. Bonifacich², J. I. Pérez-Landazábal^5,6, G. I. Zelada², D. Gargicevich², V. Recarte^5,6, O. A. Lambri^2*

Journal of Renewable Materials, Vol.4, No.4, pp. 251-257, 2016, DOI:10.7569/JRM.2016.634111

Abstract The denaturation processes of collagen in the temperature range between 450 K and 670 K are revealed through studies performed on cow rib bones by means of mechanical spectroscopy, differential scanning calorimetry, thermogravimetry, scanning electron microscopy and infrared spectroscopy. The conformational change of the collagen molecules from a triple helix structure to a random coil was found at around 510 K. It was determined that the transformation is developed through the viscous movement of fibrils with an activation energy of (127 ± 8) kJ/mol. The second stage of massive bulk deterioration of the collagen was found at around 600 K,… More >

Oscar F. Aguilar Gutierrez, Alejandro D. Rey^*

Journal of Renewable Materials, Vol.4, No.4, pp. 241-250, 2016, DOI:10.7569/JRM.2016.634119

Abstract Biological plywoods are solid analogues of liquid crystalline phases whose building blocks, including cellulose, collagen and chitin, present multifunctionality, providing in some cases protection, camouflage, self-healing and/or adaptability to the surrounding environment. The 3D ordered structure is the main factor for these fascinating properties, and the assessment of the structure-property relationship will be a powerful tool in terms of future material design and innovation. Cross-section observations lead to characteristic patterns depending on the specific arrangement of the plywood’s building blocks. Twisted plywood architectures, known as the Bouligand structure, lead to the widely observed arced patterns which can be ideal or… More >

Mirta Inés Aranguren, Arantxa Eceiza

Journal of Renewable Materials, Vol.4, No.4, pp. 239-239, 2016, DOI:10.7569/JRM.2016.634125

Abstract There is an increasing awareness among the general public of the importance of the intelligent use of earth’s biological resources for the production of chemicals, materials and precursors, resulting in an economy that is turning towards considering the valuable contributions offered by these resources. To face the present challenges of reducing the use of nonrenewable resources and the negative impact of polymer pollution on the environment, the world’s scientists are making their contribution by unraveling biological structures and studying and developing new materials and applications from biomass resources. More >

Evelien Uitterhaegen^1,2, Quang Hung Nguyen^1,2, Othmane Merah^1,2, Christian V. Stevens³, Thierry Talou^1,2, Luc Rigal^1,2, Philippe Evon^1,2*

Journal of Renewable Materials, Vol.4, No.3, pp. 225-238, 2016, DOI:10.7569/JRM.2015.634120

Abstract New fiberboards were manufactured from a coriander cake through thermo-pressing, and the influence of thermo-pressing conditions (temperature, pressure and time) on the boards’ mechanical properties, their thickness swelling and their water absorption was evaluated. Because the protein glass transition systematically occurred during molding, this resulted in effective wetting of the fibers. Consequently, all boards were cohesive, with proteins and fibers acting as binder and reinforcing fillers, respectively. Flexural properties were influenced by all tested conditions, and the optimal board was molded at 200 °C temperature, 36.8 MPa pressure and 180 s time. Its flexural strength at break and its elastic… More >

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 for a certain period of… More >

Mercedes Echegaray¹, Gurutz Mondragon¹, Loli Martin², Alba González³, Cristina Peña-Rodriguez¹, Aitor Arbelaiz^1*

Journal of Renewable Materials, Vol.4, No.3, pp. 206-214, 2016, DOI:10.7569/JRM.2016.634106

Abstract Organic rodlike cellulose nanocrystals extracted from sisal fibers and inorganic montmorillonite based on silicate layers were employed to develop bionanocomposites based on gelatin matrix. Bionanocomposites with cellulose nanocrystal, montmorillonite and both nanoreinforcements combined were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and differential scanning calorimetry. Tensile properties and oxygen and water vapor gas permeability values were determined to study the influence of the addition of nanoreinforcements, different in nature, to gelatin matrix. Bionanocomposites with montmorillonite improved tensile strength but systems reinforced with nanocellulose showed lower tensile strength than neat gelatin ones. Oxygen gas permeability values decreased for all bionanocomposites,… More >

D. Puglia^1*, F. Dominici¹, M. Badalotti², C. Santulli³, J.M. Kenny¹

Journal of Renewable Materials, Vol.4, No.3, pp. 199-205, 2016, DOI:10.7569/JRM.2016.634102

Abstract In this work, cocoa bean shells (CBS), which were ground, then sieved to less than 150 μm and dried in a vacuum oven, have been introduced in a polycaprolactone (PCL) matrix in three different amounts, 10, 20 and 30% wt. The obtained composites were tested under tensile loading, which indicated an enhanced rigidity with a slight decrease of strength with respect to the neat polymer and a reduced elongation, particularly evident for composites with 30 wt% CBS, where final collapse took place for strains only slightly exceeding the yielding point. Differential scanning calorimetry (DSC) indicated a rather negligible variation of… More >

F. Luzi, E. Fortunati^*, D. Puglia, R. Petrucci, J.M. Kenny, L. Torre

Journal of Renewable Materials, Vol.4, No.3, pp. 190-198, 2016, DOI:10.7569/JRM.2015.634134

Abstract In this research, the revalorization of Posidonia oceanica leaf sea waste was studied and the acid hydrolysis processing times were modulated in order to optimize the extraction of cellulose nanocrystals (CNCs). The obtained CNCs were deeply investigated. A two-step treatment was applied to extract cellulose nanocrystals from Posidonia oceanica leaves. First, a chemical treatment leads to the removal of lignin and production of holocellulose, while the second chemical process of acid hydrolysis allows the obtainment of cellulose nanocrystals in aqueous suspension. The unbleached and bleached leaves and cellulose nanocrystals were characterized by using thermogravimetric analysis, infrared spectroscopy and morphological investigation;… More >