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 >

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 >

Estefanía Lidón Sánchez-Safont¹, Jennifer González-Ausejo¹, José Gámez-Pérez¹, José María Lagarón², Luis Cabedo^1*

Journal of Renewable Materials, Vol.4, No.2, pp. 123-132, 2016, DOI:10.7569/JRM.2015.634127

Abstract Novel biodegradable composites based on poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) and different contents of purifi ed alpha-cellulose fi bers (3, 10, 25 and 45%) were prepared by melt blending and characterized. The composites were characterized by scanning electron microscopy (SEM), wide-angle X-ray scattering (WAXS) experiments, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanic analysis (DMA) and Shore D hardness measurements. Disintegrability under composting conditions was studied according to the ISO 20200 standard. Morphological results showed that high dispersion of the fi bers was achieved during mixing. Good adhesion on the fi ber-matrix interface was also detected by More >

Estela Krause Sammartino^1,2,3†, María Marta Reboredo⁴, Mirta I. Aranguren^*,4

Journal of Renewable Materials, Vol.4, No.2, pp. 101-112, 2016, DOI:10.7569/JRM.2014.634144

Abstract Composites made from polypropylene (PP) and local South American fibers traditionally used in yarnderived craftsmanships, Caranday Palm, were studied regarding the effect of fiber addition, concentration and characteristics of the coupling agent (molecular weight and percentage of grafted maleic anhydride), as well as type of processing. A laboratory-scale intensive mixing followed by compression, and pilot plant twin extrusion followed by injection, were the two processes investigated. The use of the first one allowed the selection of processable formulations with high fiber concentration and a percentage of coupling agent below the surface fiber saturation. In fact,… More >

Xiaoqing Zhang^*, Simon Schmidt^φ, Nick Rigopoulos, Januar Gotama, Eustathios Petinakis

Journal of Renewable Materials, Vol.3, No.2, pp. 91-100, 2015, DOI:10.7569/JRM.2014.634135

Abstract The behavior of a biodegradable CO₂ -based polymer polypropylene carbonate (PPC) as polymer matrix of wood fi ber (WF) composites was examined and compared with that of using poly(lactic acid) (PLA) as the matrix. The PPC/WF composites displayed poor mechanical properties as compared to PLA/WF composites because PPC is an amorphous polymer with low T_g and poor thermal stability. However, when PPC was used in conjunction with PLA in WF composites, the mechanical strength and modulus of the composites could match or even exceed the level of PLA/WF composites. The strong intermolecular interactions between PPC and More >

John C. Hoiby¹, Anil N. Netravali^2,*

Journal of Renewable Materials, Vol.3, No.3, pp. 244-258, 2015, DOI:10.7569/JRM.2015.634110

Abstract This article discusses the construction (virtual model) of a fully green cabin using two types of green composites: those that use natural plant-based fibers with soy protein-based resin which have mechanical properties comparable to wood and wood products, and those that use liquid crystalline cellulose fibers with soy proteinbased resin which have properties comparable to high strength steel. Green composites with moderate strength were used to create molded walls and advanced green composites were used to create the load-bearing framework of the cabin. Construction with molded composites and prefabricated framework can greatly simplify traditional wood More >

Ali Amiri, Nassibeh Hosseini, Chad A. Ulven^*

Journal of Renewable Materials, Vol.3, No.3, pp. 224-233, 2015, DOI:10.7569/JRM.2015.634111

Abstract Natural fibers have great potential to be used as reinforcement in composite materials. Cellulose, being a critical constituent of natural fibers, provides unquestionable advantages over synthetically produced fibers. Increasing demand for use of bio-based composites in different engineering and structural applications requires proper test methods and models for predicting their long-term behavior. In the present work, the time-temperature superposition principle was successfully applied to characterize creep behavior of flax/vinyl ester composites. The creep compliance vs time curves were determined and shifted along the logarithmic time axis to generate a master compliance curve. The time-temperature superposition More >

Vikram Yadama^*, Michael P. Wolcott

Journal of Renewable Materials, Vol.3, No.3, pp. 216-223, 2015, DOI:10.7569/JRM.2015.634103

Abstract The effects of strand undulation angles in wood-strand composites have often been ignored due to the virtual impossibility of experimental determination of their effects on composite material properties, and the diffi culty in modeling localized deviations in angle along the path of a strand. The fi ber undulation model (FUM), that has been previously verifi ed, was applied in this study to predict the elastic constants of laboratory-manufactured oriented strand panels. A stochastic approach was incorporated where a series rule of mixtures with probability density functions of angle distributions was utilized in the model to More >

Nassibeh Hosseini¹, Samad Javid¹, Ali Amiri¹, Chad Ulven^1,*, Dean C. Webster², Ghodrat Karami¹

Journal of Renewable Materials, Vol.3, No.3, pp. 205-215, 2015, DOI:10.7569/JRM.2015.634112

Abstract In this study, a novel, bio-based polyol was used in the formulation of a polyurethane (PU) matrix for a composite material where fl ax fi ber was used as the reinforcement. The viscoelastic properties of the matrix and fl ax fi ber were determined by a linear viscoelastic model through experimentation and the results were used as input for the material properties in the computational model. A fi nite element micromechanical model of a representative volume element (RVE) in terms of repeating unit cells (RUC) was developed to predict the mechanical properties of composites. Six… More >

K. M. Hess, W. V. Srubar III^*

Journal of Renewable Materials, Vol.3, No.3, pp. 175-182, 2015, DOI:10.7569/JRM.2015.634106

Abstract This article concerns the development and characterization of a protein-based alternative to traditional fiberreinforced polymer (FRP) composites used in construction. In this work, gelatin-based resins were prepared at various gelatin-to-water (g/w) ratios. The effects of g/w ratio and curing time on resin mechanical properties were investigated. Using gelatin resins with a 30% g/w ratio, (i) gelatin-flax and (ii) gelatin-fiberglass composites were fabricated, and their mechanical properties were characterized and compared to both (iii) epoxy-flax and (iv) epoxy-fiberglass composites. Fracture surface morphologies were investigated using scanning electron microscopy. Results indicate that gelatin-flax composites exhibit similar mechanical More >