Galia Moreno, Karla Ramirez, Marianelly Esquivel, Guillermo Jimenez*

Journal of Renewable Materials, Vol.7, No.1, pp. 9-20, 2019, DOI:10.32604/jrm.2019.00017

Abstract Poly(lactic acid) (PLA) composite films reinforced with microcrystalline cellulose (MCC) extracted from pineapple leaf fibers (PALF) were prepared by a solution casting procedure. In an attempt to improve the interaction between PLA and cellulose, two approaches were adopted; first, poly(ethylene glycol) (PEG) was used as a surfactant, and second, the cellulosic fibers were pre-treated using tert-butanol (TBA). Lignocellulosic and cellulosic substrates were characterized using Fourier transform infrared (FTIR), wide-angle X-ray scattering (WAXS), and thermogravimetrical analysis (TGA). MCC from PALF showed good thermal stability, left few residues after decomposing, and exhibited high crystallinity index. Mechanical, thermal More >

A.G. Gouater Issola¹, A. Ngueteu Kamlo², A.M. Cheumani Yona^1,*, M. Kor Ndikontar¹

Journal of Renewable Materials, Vol.6, No.6, pp. 642-650, 2018, DOI:10.7569/JRM.2018.634108

Abstract Chemical modification of cassava starch by transesterification of a vegetable oil (palm kernel oil) using aluminum chloride as a Lewis acid catalyst was achieved under relatively mild conditions (temperature 60–110 °C; atmospheric pressure). The reaction was carried out without any additional solvent. The modified starch was characterized by degree of substitution (DS), FTIR, X-ray diffraction and thermal analysis. DS of 0.09 to 0.53 were obtained. The cassava starch presented an X-ray diffraction pattern of a type A starch. X-ray analyses showed that the reaction did not significantly affect the crystallinity of starch. The modified starch More >

Sofía Collazo-Bigliardi^1,*, Rodrigo Ortega-Toro², Amparo Chiralt Boix¹

Journal of Renewable Materials, Vol.6, No.6, pp. 599-610, 2018, DOI:10.32604/JRM.2018.00127

Abstract Cellulosic fibres from coffee (CF) and rice (RF) husks have been obtained applying chemical treatments and characterized as to their microstructure and thermal behaviour. These materials have been incorporated into glycerol plasticised thermoplastic starch (TPS) films obtained by melt blending and compression moulding at 1 wt%, 5 wt% and 10 wt%. Microstructure, thermal behaviour and optical, tensile and barrier properties of the composites were analysed. Both kinds of micro-fibres improve the film stiffness while reduced the film stretchability. However, CF better maintained the film ductility at 1 and 5 wt%. A network of fine oriented More >

W. Li¹ and T. Siegmund¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.1, pp. 81-90, 2004, DOI:10.3970/cmes.2004.005.081

Abstract Results of a computational study of the mechanics of indentation induced interface delamination are described for a system consisting of a ductile film on an elastic substrate. Special attention is paid to the properties of the interface between film and substrate, and the influence of the interface properties on the indentation response. Specifically, strong interfaces are considered. The interface is characterized by the use of a cohesive zone model. The finite element method is used to solve the boundary value problem, with the interface behavior incorporated via a cohesive model in a traction-separation formulation. The More >

Victor Gomes Lauriano Souza¹, Patrícia Freitas Rodrigues², Maria Paula Duarte¹, Ana Luísa Fernando^1*

Journal of Renewable Materials, Vol.6, No.5, pp. 548-558, 2018, DOI:10.7569/JRM.2018.634104

Abstract The aim of this work was to develop an active biopolymer based on chitosan by incorporating natural antioxidants. Five essential oils (ginger, rosemary, sage, tea tree and thyme) and six hydro-alcoholic extracts (from ginger, green and black tea, kenaf leaves, rosemary and sage plants) were tested. Migration assays were carried out to evaluate the films' activity, and total phenolic content and antioxidant activity were monitored in the simulant during storage. Interaction between natural compounds and polymeric matrix was evaluated by FTIR spectroscopy. The diffusion of the phenolic compounds was not detected in the films incorporated More >

Christophe Olivier^1,2, Jean Bruno Mougel^1,2, Patricia Bertoncini¹, Celine Moreau², Isabelle Capron², Bernard Cathala², Olivier Chauvet^1*

Journal of Renewable Materials, Vol.6, No.3, pp. 237-241, 2018, DOI:10.7569/JRM.2017.634168

Abstract Cellulose nanocrystals (CNCs) have a high ability to disperse single-walled carbon nanotubes (SWNTs) in aqueous media and to form hybrids. These hybrids are used to grow layer-by-layer thin films of controlled thickness. Thanks to the presence of SWNTs, these films are conducting. In this article, we describe the process by which the CNC/SWNT hybrids are obtained and discuss the electrical properties of the hybrid-based layer-by-layer films. More >

Karolina Villalobos¹, Hider Rojas¹, Rodolfo González-Paz², Daniel Brenes Granados², Jeimmy González-Masís², José Vega Baudrit^1,3, Yendry Regina Corrales-Ureña^1*

Journal of Renewable Materials, Vol.5, No.3-4, pp. 189-198, 2017, DOI:10.7569/JRM.2017.634109

Abstract Because starch is a biodegradable polymer with low cost and wide availability it is an attractive material for producing edible films for fruits. Films produced with pure starch have the disadvantage of being fragile. To overcome this issue, propolis nanoparticles were used as a novel plasticizer. Mechanical, thermal and morphological properties of the films containing 0.5, 1 and 3 wt.% propolis nanoparticles were evaluated. The best performance was obtained using 0.5 wt.% propolis, increasing the Young’s modulus and decreasing the glass transition temperature (Tg), showing their plasticizing effect. The results of scanning electron microscopy (SEM) More >

Elena Fortunati^1*, Francesca Luzi¹, Chiara Fanali², Laura Dugo², Maria Giovanna Belluomo², Luigi Torre¹, José Maria Kenny¹, Luca Santi³, Roberta Bernini³

Journal of Renewable Materials, Vol.5, No.2, pp. 81-95, 2017, DOI:10.7569/JRM.2016.634132

Abstract Hydroxytyrosol (HTyr), a biophenol found in extra-virgin olive oil or olive oil by-products, well known for its strong antioxidant activity, was used as active ingredient for poly(vinyl alcohol) (PVA) matrix to develop film formulations by solvent casting process. The effect of HTyr on the morphological, thermal stability, optical, mechanical and release properties of PVA were investigated, while water absorption capacity, migration with food stimulants, water vapor permeability and antioxidant properties were tested taking into account the final application as food packaging systems. Morphological investigations evidenced homogeneity of all PVA/HTyr films, while the presence of HTyr More >

Mingzhe Jiang¹, S. Nicole DeMass¹, D. Ross Economy², Thomas Shackleton¹, Christopher L. Kitchens^1*

Journal of Renewable Materials, Vol.4, No.5, pp. 377-387, 2016, DOI:10.7569/JRM.2016.634131

Abstract Spin coating was used to cast a uniform film of cellulose nanocrystals with low surface roughness and variable thickness as a function of operational parameters that include rotational speed and dispense suspension concentration. The film thickness was controllable from 40 nm up to 1 μm with surface roughness an order of magnitude less than blade-coating methods. The degree of radial orientation was qualitatively assessed and shown to be variable with processing parameters. Under specific processing conditions, the formation of striation patterns was observed and associated with film drying instability. The striation patterns are periodic in… More >

Nicole M. Stark

Journal of Renewable Materials, Vol.4, No.5, pp. 313-326, 2016, DOI:10.7569/JRM.2016.634115

Abstract Performance requirements for packaging films may include barrier properties, transparency, flexibility, and tensile strength. Conventional packaging materials, such as plastic films and laminates, are typically made from petroleum-based polymers. Currently, there is a drive to develop sustainable packaging materials. These alternative materials must be able to be manufactured economically and on a commercial scale, exhibit barrier properties and transparency, and provide adequate mechanical performance. As a biobased, renewable material, cellulose nanomaterials (CNs) are ideally suited to be used in sustainable packaging applications. CNs include cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) and each can provide More >