Bernal Sibaja^1,2,3, Camila Pereira Matheus^1,2, Ricardo Ballestero Mendez^1,2, J. R. Vega-Baudrit³, Maria L. Auad^*,1,2

Journal of Renewable Materials, Vol.5, No.3-4, pp. 231-240, 2017, DOI:10.7569/JRM.2017.634113

Abstract Interpenetrating polymer networks (IPNs) using an epoxy phase synthesized from chemically modified α-resorcylic acid, and an acrylate phase employing acrylated soybean oil are the main focus of this study. Part 1 details the epoxidation of α-resorcylic acid with epichlorohydrin in alkaline medium, as well as the study of the polymerization and network formation of the generated epoxy-acrylate interpenetrated systems. The epoxy content of the epoxidized α-resorcylic acid was measured by means of a titration using HBr in acetic acid solution, and the functionalization was studied by FTIR. From the obtained results, mainly calorimetry and gel More >

Luis Daniel Mora-Murillo¹, Felipe Orozco-Gutierrez², José Vega-Baudrit², Rodolfo Jesús González-Paz^2*

Journal of Renewable Materials, Vol.5, No.3-4, pp. 220-230, 2017, DOI:10.7569/JRM.2017.634112

Abstract Nowadays, green polyurethane (PU) foams are mostly synthesized by replacing an amount of petrochemical polyol with biobased polyol. Here we report five different families of isocyanate prepolymer formulations that were prepared with biobased sources and the correlation between the structure of chains and the properties of the produced PU foam. Foam behavior in tension, torsion, compression, shape memory tests and physical properties were studied by dynamic mechanical thermal analysis (DMTA); interactions in the polymer chains were analyzed by Fourier transform infrared spectroscopy (FTIR); and thermal analysis was performed by thermogravimetry (TGA) and differential scanning calorimetry More >

Ananda S. Amarasekara^*, Muhammad A. Hasan, Eve Larkin

Journal of Renewable Materials, Vol.5, No.1, pp. 62-66, 2017, DOI:10.7569/JRM.2016.634129

Abstract Condensation polymerization of renewable resources-based monomers, 4-ketopimelic acid and glycerol, were studied using two different catalysts; p-toluenesulfonic acid and Sb2O3. The highest polymer yield of 96% was achieved by using a 3:4 mole ratio mixture of 4-ketopimelic acid and glycerol, with Sb2O3 (0.5 mol% relative to 4-ketopimelic acid) as catalyst and heating at 23–210 °C, under N2 for 1 h; then 210 °C, vacuum, 12 h. The poly(4-ketopimelic acid-glycerol) formed is insoluble in all common organic solvents and is shown to contain a branched polymeric structure with ketal and ester links by using FT-IR, 1H More >

Flores S¹, A Promis², L Faúndez³

Phyton-International Journal of Experimental Botany, Vol.85, pp. 324-332, 2016, DOI:10.32604/phyton.2016.85.324

Abstract Jubaea chilensis (Molina) Baill. (Chilean palm) is an endemic species in Chile. It has been classified as a vulnerable species because of the reduction and the fragmentation of its population numbers, the exploitation of the palms for the production of syrup, the indiscriminate harvest of seed for human consumption, and the reduction of the accompanying native vegetation cover. The southernmost limit of its natural distribution is located in Palmas de Tapihue (Pencahue, Maule region). The objective of this study was to benchmark the conservation status of this population and its accompanying vegetation. The population of J. chilensis… More >

M.N.D. Cherief¹, M. Elmeguenni¹, M. Benguediab¹

CMC-Computers, Materials & Continua, Vol.51, No.3, pp. 187-201, 2016, DOI:10.3970/cmc.2016.051.187

Abstract Impact behavior of polymers has received considerable attention in recent years, and much work based on fracture mechanic approaches has been carried out. In this paper, fracture behavior in large deformation of a high density polyethylene (HDPE) materials was investigated through experimental impact testing on single edge notched specimen (SENB) and by using theoretical and analytical fracture criteria concepts. Moreover, a review of the main fracture criteria is given in order to characterize the toughness of this polymer in the both cases (static and dynamic). The fractured specimens obtained from the Charpy impact test were More >

Jithin Joy^1,2,3, Cintil Jose³, Srirama B. Varanasi⁴, Lovely Mathew P.^2,3, Sabu Thomas², Srikanth Pilla^1,5*

Journal of Renewable Materials, Vol.4, No.5, pp. 351-364, 2016, DOI:10.7569/JRM.2016.634128

Abstract Isora nanofibers (INF) were produced by a combined thermal-chemical-mechanical method from Helicteres isora plant. The resulting fibers were analyzed using transmission electron microscopy and scanning electron microscopy, which showed a network-like structure with a length of 600 nm, width of 50 nm and an aspect ratio of 12. Fourier transform infrared spectroscopy indicated that chemical treatments progressively removed noncellulosic constituents. X-ray diffraction analysis revealed that crystallinity increased with successive chemical treatments. Using the synthesized isora nanofibers, poly(butylene succinate) (PBS)-based biodegradable nanocomposites were prepared. The nanocomposites were processed using a Brabender twin-screw compounder and an injection… More >

Facundo I. Altuna¹, Borja Fernández-d’Arlas², M. Angeles Corcuera², Arantxa Eceiza², Mirta I. Aranguren³, Pablo M. Stefani^3*

Journal of Renewable Materials, Vol.4, No.4, pp. 275-284, 2016, DOI:10.7569/JRM.2016.634120

Abstract Mixtures of biomass-derived polyols were used to synthesize rigid polyurethane (PU) foams. A commercial polymerized methylene diphenyl diisocyanate (pMDI) was used as crosslinker, and distilled water served as foaming agent. The morphology and mechanical properties of foams with different glycerol and water contents were compared in order to evaluate the most suitable formulations. The rigid foams with higher water contents had larger and more anisotropic cells, explaining their lower density. Compressive moduli ranged from about 2.5 MPa to above 20 MPa and collapse stresses from 55 kPa to more than 1 MPa for densities between 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… 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 More >

Karina Cruz-Aldaco¹, Erika Flores-Loyola², Cristóbal Noé Aguilar-González¹, Nuria Burgos³, Alfonso Jiménez^3*

Journal of Renewable Materials, Vol.4, No.3, pp. 178-184, 2016, DOI:10.7569/JRM.2016.634107

Abstract The use of vegetable oils to replace fossil feedstock has become an area of opportunity and a priority for study in the field of polymer science. Vegetable oils are considered as renewable resources with high potential, low cost and full availability. The aim of this study is the synthesis of biobased polyols from cottonseed oil (Gossypium barbadanse) and corn oil (Zea mays) as feedstock. Their synthesis was successfully performed, as can be concluded from the determination of their hydroxyl index as well as the structural and thermal characterization carried out in this work. Polyurethanes from More >