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 provided an accelerated method for… 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 transform the elastic constants in… 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 loading conditions were applied on… More >

D.N. Dorr, S.D. Frazier, K.M. Hess, L.S. Traeger, W.V. Srubar III^*

Journal of Renewable Materials, Vol.3, No.3, pp. 195-204, 2015, DOI:10.7569/JRM.2015.634108

Abstract A study of the potential for gelatin-based derivatives to serve as biorenewable, biodegradable adhesives for wood and engineered wood products is presented in this article. The effect of gelatin-to-water weight percent on the mechanical, specifically ultimate breaking (bond) strength, and thermal properties was investigated using tensile testing and differential scanning calorimetry, respectively. The breaking strengths of the gelatin-based adhesives were characterized and compared to four commercially available wood adhesives. The effect of 1–5% tannin addition on the mechanical, thermal, and moisture absorption behavior of the gelatin-based adhesives was also investigated. Results show that the gelatin-based materials demonstrate 1) appropriate thermal… More >

Henning Roedel¹, Isamar Rosa Plata¹, Michael Lepech^1,*, David Loftus²

Journal of Renewable Materials, Vol.3, No.3, pp. 183-194, 2015, DOI:10.7569/JRM.2015.634107

Abstract This article presents the sustainability assessment of a novel biocomposite material that is under investigation by NASA for use in construction in limited resource environments. The composite consists of soil particles solidified by a protein binding agent. Preliminary compressive strength data suggests the biocomposite could be used for numerous construction applications. To assess the biocomposite’s potential for use in sustainable construction, a comparative process-based life cycle assessment between biocomposite and concrete pavers was performed to analyze the life cycle primary energy and IMPACT 2002+ points of both types of pavers. Results show that the concrete pavers outperform the biocomposite pavers… 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 properties compared to the epoxy-fiberglass… More >

Mike Lawrence

Journal of Renewable Materials, Vol.3, No.3, pp. 163-174, 2015, DOI:10.7569/JRM.2015.634105

Abstract The relative importance of embodied energy and operational energy on the environmental impact of construction are examined in this article. It highlights the fact that the targets set by the Kyoto Protocol are primarily being met by the reduction of in-use energy, and that the implications of that are that the energy embodied in buildings will increase in signifi cance from its current 17% level to 50% by 2050. The article describes how the use of bio-based renewable materials can make a signifi cant contribution to reducing not only the embodied energy of buildings by using the sequestration of CO2… More >

Journal of Renewable Materials, Vol.3, No.3, pp. 161-162, 2015, DOI:10.7569/JRM.2015.634113

Abstract This article has no abstract. More >

Yujie Zhang¹, Marc A. Dubé^1,*, Eduardo Vivaldo-Lima²

Journal of Renewable Materials, Vol.3, No.4, pp. 318-326, 2015, DOI:10.7569/JRM.2015.634115

Abstract Renewable monomers containing allylic C-H bonds in their structure are prone to degradative chain transfer in free-radical polymerization, which will dramatically decrease the polymerization rate. In order to understand this mechanism, a kinetic model incorporating a degradative chain transfer mechanism for the free-radical copolymerization of d-limonene (LIM) and n-butyl methacrylate (BMA) was developed using PREDICI. Model predictions offered insight on how degradative chain transfer reactions affect conversion, copolymer composition and molecular weight in the polymerization. Experimental data from copolymerizations at monomer feed compositions (LIM/BMA, mol/mol) of 10/90, 20/80 and 30/70 were compared to the model’s predictions. Moreover, it was discovered… More >

Mario Alejandro Mejía Escobar^*, Franklin Jaramillo^*

Journal of Renewable Materials, Vol.3, No.4, pp. 302-317, 2015, DOI:10.7569/JRM.2014.634121

Abstract Energy alternatives have been one of the most important research focal areas of the last decade due to the imminent lack of fossil fuels. This motivation has allowed the evolution of the materials science field in areas such as electrochemistry, where high availability, low cost and negligible environmental impact are the desired principal qualities. For this reason, as an example of a photoelectrochemical device, we have proposed the use of natural dyes from 37 agro-industrial wastes in dye-sensitized solar cells. We obtained dyes from red cabbage, radish and roselle wastes with a good stability for eight hours with a constant… More >