ABSTRACT
One of the activities most representative of the agricultural sector in Colombia is the production of biodegradable fique fiber. The efficiency of the defiberization process of the fique leaves is very low since a mere 4% of the total weight of the leaf (cabuya) is used and marketed. The remaining 96%, composed of fique juice and bagasse, is considered to be waste and discarded, impacting the environment. The aim of this work was to study fique bagasse as a source of cellulose nanoparticles (CNCs). CNCs were obtained by acid hydrolysis and added at 10% to films made from cassava thermoplastic starch (TPS) by the casting method. Structural changes in the CNCs, TPS, and their mixtures were characterized by FTIR-ATR and their morphology and particle size by SEM and TEM microscopy, respectively. Thermal properties were analyzed using DSC and TGA, along with their effect on mechanical properties. Changes in the FTIR spectra indicated that the chemical method adequately removed hemicellulose and lignin from the fiber surface of fique bagasse. The CNCs showed a diameter and length of 7.5 ± 3.9 and 52.7 ± 18.1 nm, respectively, and TPS 10% CNC obtained an increase in mechanical strength of 116%. The obtainment of CNCs from lignocellulosic materials can thus be viewed as a favorable option for the subsequent reinforcement of a polymeric matrix.
ABSTRACT
This work aims to evaluate the effect of the addition of a high-protein hydrolyzed (HPH) flour from the chemical silage of trout (Oncorhynchus mykiss) residues on the parameters of the extrusion system physicochemical transformations and the microstructure of the extrudate. During the extrusion process, the materials used for the study were the HPH flour obtained from trout by chemical silage, fishmeal, and cassava starch. The extrudate's microstructural changes were evaluated by determining the porosity, scanning electron microscopy, the chemical changes, the amino acid profile, residual formic and lactic acid content, the molecular mass profile, the grade of hydrolysis, and in vitro digestibility. The results showed pellets with high durability due to the cohesiveness of the hydrolyzed protein flour but at the same time with low hardness due to the high porosity achieved. The monitoring carried out to the changes in the protein, such as the degree of hydrolysis, water-soluble protein, and molecular mass profile, verify the binding effect of the high-protein hydrolyzed flour during the extrusion process. Finally, the high-resolution optical microscopy methodology presented a high correlation with the phenomena presented in the experiment.
ABSTRACT
Contamination caused by the accumulation of petrochemical-based plastics has reached worrying magnitudes and led to the development of biopolymers as an option to mitigate the problem. This work thus presents a bibliometric analysis of all that concerns the development of such bionanocomposite materials, using ScientoPy and SciMAT software to establish associations between the number of published documents, countries, institutions and most relevant topics. The bionanocomposites topic was found to throw up the biggest number of documents associated (2008) with the different types of raw materials and methods used to obtain nanoparticles and their combination with biopolymeric materials, the result known as a "bionancomposite*". Analysis of the documents related to the application for development of packaging materials from biological molecules, carbohydrate polymers, compounds, conjugates, gels, glucans, hydrogels, membranes, mucilage (source unspecified), mucoadhesives, paper, polymers, polysaccharide, saccharides etc, is also presented, emphasizing mechanical, thermal and barrier properties, which, due to the inclusion of nanoparticles mainly from natural sources of cellulose, show increases of up to 30%. The inclusion of nanoparticles, especially those derived from cellulose sources, generally seeks to increase the properties of bionanocomposite materials. Regarding an increase in mechanical properties, specifically tensile strength, inclusions at percentages not exceeding 10 wt% can register increases that exceed 30% were reported.
Subject(s)
Acids/chemistry , Biocompatible Materials/chemistry , Biopolymers/chemistry , Food Packaging , Lignin/chemistry , Nanocomposites/chemistry , Bibliometrics , Biocompatible Materials/chemical synthesis , Cluster Analysis , Data AnalysisABSTRACT
TPS/MA/PLA is a blend of thermoplastic starch (TPS) and polylactic acid (PLA) compatibilized by maleic anhydride (MA) that can be a substitute for petro-based plastics in certain applications. At the end of its life, this material must be properly disposed in treatment systems such as composting or anaerobic digestion. The biodegradability of TPS/MA/PLA, PLA, TPS and the non-compatible mixture (TPS/PLA) was evaluated in a slurry thermophilic anaerobic digestion system (STAD) according to ISO 13975-2012 standard. The anaerobic inoculum was prepared from cow manure and the organic fraction of municipal solid waste. After 31â¯days of incubation, the pure PLA exhibited a 12-day lag phase and 40.41% of biodegradability. TPS, TPS/PLA and TPS/MA/PLA did not exhibit lag phase and reached 92.11%, 65.48% and 64.82% of biodegradation respectively. The slow degradation rate of PLA is attributed to its high glass transition temperature and crystallinity. In TPS/MA/PLA and TPS/PLA, about 50% of PLA and 13% to 10% of the TPS remains undegraded and MA did not affect the biodegradation of TPS/MA/PLA compared to TPS/PLA. Results suggest that, in very short retention times STAD systems, PLA based materials could not exhibit enough biodegradability.
Subject(s)
Biodegradation, Environmental , Maleic Anhydrides/chemistry , Polyesters/chemistry , Starch/chemistry , Anaerobiosis/genetics , Hot TemperatureABSTRACT
Polylactic acid (PLA) and starch are compounds used in the manufacture of packaging to replace petroleum products as biodegradable and environmentally friendly materials. This study evaluated the structure and surface of a film manufactured by extrusion from cassava starch and PLA, which underwent a biodegradation process under compost conditions following the guidelines of ISO 4855-2:2007. Samples were taken every week for one month to perform Fourier Transform Infrared Spectroscopy (FT-IR) tests to identify functional groups on film, and High-Resolution Optical Microscopy (HROM) and Scanning Electron Microscopy (SEM) tests, from these techniques Structural changes in the film were evidenced. The addition of PLA increases the carbonyl index. The introduction of anhydrous malic acid (MA) in PLA/TPS mixtures may lead to an increase in the carbonyl index, The TPS/PLA composite film was framed in the three phases of biodegradation: disintegration, fragmentation, and mineralization. In week 4 a reduction in film size was observed with a thinning of the film with fractures that produced fragmentation and disintegration.