Muhammad Ghozali^1,2, Yenny Meliana², Widya Fatriasari³, Petar Antov⁴, Mochamad Chalid^1,*

Journal of Renewable Materials, Vol.11, No.4, pp. 1963-1976, 2023, DOI:10.32604/jrm.2023.026060

Abstract Sugar palm (Arenga pinnata) starch is considered an important renewable, biodegradable, and eco-friendly polymer, which is derived from agricultural by-products and residues, with great potential for the development of biocomposite materials. This research was aimed at investigating the development of TPS biocomposites from A. pinnata palm starch using an extrusion process. Palm starch, glycerol, and stearic acid were extruded in a twin-screw extruder. Scanning electron microscopy (SEM) analysis of TPS showed that the starch granules were damaged and gelatinized in the extrusion process. The density of TPS was 1.3695 g/mL, lower than that of palm starch, and the addition of… More > Graphic Abstract

Fengwei Xie^1,*, Paul Luckman¹, John Milne¹, Lachlan McDonald¹, Conor Young¹, Chen Yang Tu¹, Teo Di Pasquale¹, Reinhard Faveere¹, Peter J. Halley^1,2

Journal of Renewable Materials, Vol.2, No.2, pp. 95-106, 2014, DOI:10.7569/JRM.2014.634104

Abstract Starch is a biopolymer that is widely available from agriculture/nature and thus is renewable and cheap. In addition, starch-based materials are biodegradable, offering a great advantage over traditional nonbiodegradable synthetic polymers. However, the poor processibility and product performance of starch have greatly impeded the wide application of starch in real applications. This paper reviews the current developments of the production of thermoplastic starch as a commodity renewable material. The biological origins of the feedstock, formulation development, processing requirements, as well as the important aspects that need to be addressed when designing a product from starch are discussed. It is hoped… More >

Mayte M. Quispe^1,*, Olivia V. López¹, Marcelo A. Villar^1,2

Journal of Renewable Materials, Vol.7, No.4, pp. 383-391, 2019, DOI:10.32604/jrm.2019.04276

Abstract Among biopolymers, thermoplastic starch (TPS) is a good candidate to obtain biomaterials because of its natural origin, biodegradable character, and processability. Exposure to ultraviolet (UV) radiation causes significant degradation of starch-based materials, inducing photooxidative reactions which result in breaking of polymer chains, production of free radical, and reduction of molar mass. These changes produce a deterioration of TPS mechanical properties, leading to useless materials after an unpredictable time. In this work, changes induced on TPS by UV radiation, analyzing structural properties and mechanical behavior, are studied. TPS was obtained through thermo-mechanical processing of native corn starch in the presence of… More >

María G. Passaretti^1,2,*, Mario D. Ninago^3,4, Cecilia I. Paulo⁵, Horacio A. Petit⁵, Edgardo F. Irassarc⁵, Daniel A. Vega⁶, Marcelo A. Villar^1,2, Olivia V. López¹

Journal of Renewable Materials, Vol.7, No.4, pp. 393-402, 2019, DOI:10.32604/jrm.2019.04281

Abstract Granite stone is a by-product of the rock crushing manufacturing. An industrial waste in powder form that causes health problems and environmental pollution. Fine particles fraction can be used as a partial replacement of sand in concrete manufacture. In this work, an alternative exploitation of this waste fraction is proposed. Granite sand (GS) with particles mean size of ~1 μm was employed as thermoplastic starch (TPS) filler at different concentrations. Biocomposites were obtained by melt-mixing and thermo-compression, achieving translucent and easy to handle films. A good GS dispersion within the matrix was evidenced by SEM. Mineral presence induced a shift… More >

Ana Clara Lancarovici Alves, Rafael Grande, Antonio José Felix Carvalho^*

Journal of Renewable Materials, Vol.7, No.3, pp. 245-252, 2019, DOI:10.32604/jrm.2019.00833

Abstract The interest in thermoplastic starch (TPS) as a substitute material to replace conventional thermoplastics continues especially due its biodegradability, availability, low cost and because it is obtained from renewable sources. However, its poor mechanical properties and its high sensitivity to humidity have limited its use in several applications. Here, the copolymer poly (ethylene-co-vinyl alcohol) (EVOH), with two different ethylene contents, 27 and 44 mol% were blended with TPS by extrusion in order to overcome these limitations. The obtained blends were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), mechanical tensile testing, Scanning Electron Microscopy (SEM) and moisture absorption test.… More >

Anna Kundys^1,*, Justyna Ostrowska², Urszula Chojnacka¹, Zuzanna Grodzka¹, Aleksandra Lange¹, Magdalena Paluch²

Journal of Renewable Materials, Vol.6, No.6, pp. 611-618, 2018, DOI:10.32604/JRM.2018.00134

Abstract The degradation of thermoplastic starch blend in the presence of commercial α-amylase and unpurified amylase of microbial origin was investigated. The blends consisting of thermoplastic starch and poly(butylene succinate) have potential use in packaging applications thus, it is essential to establish susceptibility to degradation. Molar mass loss, gravimetric weight loss, and molecular structure were evaluated. The changes in the surface were observed with scanning electron microscopy. It was confirmed that there was a significant difference in gravimetric weight loss between the blends degraded in two different solutions. Unpurified enzymes of microbial origin, produced by Rhizopus oryzae cultures decomposed analyzed materials… 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 fibres was observed on the… More >

Andrea Dorigato^1,*, Martino Negri², Alessandro Pegoretti^1,*

Journal of Renewable Materials, Vol.6, No.5, pp. 493-503, 2018, DOI:10.7569/JRM.2017.634177

Abstract Novel fully biodegradable thermoplastic composite laminates reinforced with ultrathin wood laminae were prepared through a hot-pressing process by using two different thermoplastic starch (TPS) matrices. The microstructure and physical properties of the resulting unidirectional and bidirectional laminates were studied. The investigated materials presented a complex microstructure, in which the porosity of the wood laminae was almost entirely occluded by the polymer matrix. The mechanical behavior of the laminates was strongly affected by the obtained microstructure, and matrix penetration in wood pores led to biodegradable composites with elastic modulus and tensile strength higher than those of their constituents. Finally, thermal welding… More >

Bruno Henrique dos Santos, Karen de Souza do Prado, Asaph Armando Jacinto, Márcia Aparecida da Silva Spinacé*

Journal of Renewable Materials, Vol.6, No.2, pp. 176-182, 2018, DOI:10.7569/JRM.2018.634101

Abstract Although thermoplastic starch (TPS) is biodegradable, its low mechanical resistance limits its wide application. Sugarcane bagasse (SB) fibers can be used as reinforcement in TPS matrix composites, but the influence of fiber size on the properties of the composite is still unknown. In this study, TPS composites reinforced with SB short fibers of four sizes were processed and characterized in order to analyze the influence of fiber size on the mechanical properties of the TPS/SB composite. It was observed that the interaction between fiber and matrix was good and optimized when the fibers are sifted in sieves between 30 and… More >

Liliane Cruz Gomes de Souza Santos^1*, Eliane Ayres², Flávio Renato de Góes Padula¹

Journal of Renewable Materials, Vol.5, No.3-4, pp. 307-312, 2017, DOI:10.7569/JRM.2017.634121

Abstract In this study, bamboo powder and/or hollow glass microspheres were added to thermoplastic cassava starch in order to overcome its drawbacks. The composites were characterized by scanning electron microscopy (SEM), tensile testing, water contact angle measurement and X-ray diffractometry (XRD), in addition to their thermal properties. The mechanical strength of the composites showed a general decline with increasing bamboo powder content while the water contact angles increased up to 15% of bamboo powder content (% w/w dry starch). The addition of hollow glass microspheres provides an optimal balance between hydrophobicity and mechanical strength. The results pointed to improved properties that… More >