Papers by Keyword: Biopolymer

Abstract: The conversion of seafood waste into valuable materials is essential for advancing seafood sustainability. Crab shells, which are a major byproduct, generate a large volume of waste annually and are a key source of chitin and chitosan. This study explores the extraction and characterisation of chitin and chitosan from Irish brown crab (Cancer pagurus) shell waste using chemical methods. Samples of crab shell waste (CSW), extracted chitin (CT) and chitosan (CTS) were analysed and compared to commercial chitosan (CTS-c) in terms of chemical, thermal and structural properties. The extraction process included steps of demineralisation, deproteinisation, decolourisation and deacetylation, yielding 17.60% CT and 50.45% CTS, which aligns with previously published values. FTIR analysis confirmed structural changes from CSW to CT followed by CTS, shown by distinct spectral shifts, with CTS exhibiting a degree of deacetylation (DD) of 78.53%, comparable to CTS-c (79.53%). DSC findings showed increased enthalpy, ΔH from 72.58 J/g (CSW) to 253.28 J/g (CTS), indicating improved thermal stability. SEM images displayed morphological transformations from porous CT to denser CTS, with porosity measured by ImageJ changing from 2.87% (CSW) to 18.60% CT before decreasing to 2.71% (CTS). These outcomes highlight the feasibility of valorising Irish crab shell waste into high-quality chitin and chitosan suitable for use in end-product applications, thus promoting the concepts of a circular economy.

Abstract: This article investigated the properties and applicability of a composite containing thermoplastic starch (TPS), coffee and straw fiber. Plastics are indispensable in everyday life because these materials are used very widely, e.g. industrial and agricultural use, food packaging, cables, car parts, mattresses, medical devices, household appliances, etc. Although the use of plastics has many advantages, an environmentally conscious approach is increasingly important in modern society and therefore the disadvantageous properties of plastics have also become an issue. On the one hand, they are petroleum derivatives, which are a finite resource, and on the other hand, the life cycle of packaging materials is short. Multiple recycling is also a problem due to the deteriorating quality during recycling. The above two negative properties can be eliminated by using biopolymers, as biopolymers effectively replace single-use petroleum-based packaging products, for which recycling is difficult or impossible from environmental and economic perspectives. The aim of the pilot program was to produce a mixture of biodegradable biopolymers, including starch-based TPS polymers, coffee grounds and straw fiber, and to investigate one of the main indicators of degradable polymer composites, the degradation process by reacting in different pH matrixes (4 different water and 3 different soil-based matrixes) during a period of 0-2 months. The degradation process was analyzed by following mass and shape changes and FT-IR measurements. The applicability of the biopolymer composite was verified, as the decomposition process was proven in an aqueous medium at 72h. We were able to detect the conversion of some chemical bonds through the change of absorbance of carbonyl and CH₂ groups, CH₃ umbrella vibration. The produced mixture is planned to be used in agricultural areas as a raw material for seedling pots, which could reduce the generation of additional waste and, by using fillers, the use of the composite also provides protection against pests.

Abstract: Edible plastics/films or biopolymers are biodegradable materials which are normally applied as food packaging. This type of packaging has been used for centuries to protect food products by avoiding food deterioration and extending its shelf life. Due to the increasing concerns about health and the environment, edible films are made from biomaterials to produce safe, edible, and environmentally friendly materials. In this study, the biopolymer’s compositions are combined from different types of hydrocolloids (polysaccharides base) with gel forming ability and additives for better structure. The film is formed by applying wet formation (solvent casting technique) and dried at 55°C to create thin films. The thickness, tensile strength (TS), elongation at break (EBA), contact angle, water vapor transmission rate (WVTR), water solubility and oil solubility were determined at different proportions of used hydrocolloids. The plasticizer glycerol was added at different concentrations (10, 20, 30% w/w) for further investigation of the film’s properties.

Abstract: In this study, tensile property of green composite material using single flax yarn and shellac resin under loading speed was investigated for safety of sustainable structural materials. The molding method was compression molding method. Static tensile tests of single flax yarn and green composite material were conducted under constant temperature and humidity room. The test speed was 10-100 mm/min. Following conclusions were obtained. Tensile strength and Young’s modulus of single flax yarn and green composite material increased with an increase of test speed. From fracture observation, large damage of fiber in the green composite material at 10 mm/min and 100 mm/min did not occur after static tensile tests. But damage of fiber in flax yarn was found when static tensile tests of single flax yarns at 10 mm/min and 100 mm/min were conducted. Therefore, the effect of loading speed on tensile property of green composite material might be affected by viscoelasticity of flax fiber and matrix.

Abstract: The generation of organic waste has increased globally in recent years. One way to degrade waste more quickly and carry out the bioconversion process of organic waste is to use insects. This BSF has attracted researchers to cultivate and utilize this biomass to extract biochemicals. However, in this research, pupal skin melanin (PSM) from BSF waste is used to obtain melanin. Melanin is a group of blackish-brown pigments with strong physical, chemical, and antimicrobial properties. These properties can be used as an alternative biopolymer material for various environmental sustainability purposes. The melanin extraction method consists of three main steps, namely demineralization, deproteination, and deacetylation, which will be compared with the results of melanin purification from Sepia officinalis melanin (SOM). Characteristics using FTIR, SEM, and EDS to determine the comparison of the quality of melanin obtained from the extraction of pupal skin with commercial melanin from Sepia officinalis. The research results obtained from FTIR analysis show that there are distinctive peaks that correspond to the structure of melanin, including hydroxyl groups (-OH), amine groups (-NH), carboxyl groups (-COOH), and aromatic groups. For SEM analysis, the morphology of PSM and SOM shows differences in surface condition. The melanin resulting from Sepia officinalis is not homogeneous and contains many lumps or aggregates. Whereas the surface of melanin from pupal skin is more homogeneous or looks smoother, but there are still small aggregates on the surface. Furthermore, from the EDS analysis, the total pure concentration was 99.33% for SOM and 69.78% for PSM.

Abstract: The plastic market is under constant pressure to find viable options to replace petroleum-based polymers. Sustainability has become one crucial parameter when assessing new products or alternatives. Biopolymers are a potential replacement for synthetic plastics because they come from renewable resources. Chitin is the second most abundant biopolymer found in nature, and chitosan is the deacetylated product from chitin. Chitosan has many applications that make it an exciting option for the future. In this study, the environmental impact of the production of chitosan from Black Soldier Flies has been assessed considering a techno-environmental perspective. Three processes were evaluated in the production of chitosan from the insect with variations in the amount of reagent used from an optimization perspective. The optimized process, called the recycled process, showed a significant reduction of the environmental indicator across the 18 categories assessed. Using ReCiPe Midpoint H and SimaPro software, the global warming indicator for this process was calculated among other impact categories. One kilogram of chitosan from Black Soldier Flies emitted 7.69 kg CO₂ eq. The higher contributor to the major categories was the use of sodium hydroxide in the deproteinization and deacetylation step. Furthermore, the raw material cost for the chitosan produced from the insects is about $10, which situates this option as equal to chitosan produced from other raw materials, shrimp, or crab shells.

Abstract: To assess the safety and utility of green composite materials as a sustainable structural material, this study investigated their tensile properties using unidirectional jute fiber sliver and poly (lactic acid) and poly (butylene succinate) under loading speed. The fiber volume fraction of the green composite materials was about 10%. Vacuum compression molding was used for molding. Static tensile tests of green composite materials using poly (lactic acid) and poly (butylene succinate) were conducted with 0.1–10 mm/min test speed at room temperature, yielding the following conclusions. Tensile strengths of green composite materials using poly (lactic acid) and poly (butylene succinate) increased with increased test speed. The strain rate dependence of the green composite using poly (lactic acid) became strong, but the strain rate dependence of green composite material using poly (butylene succinate) became weak. Results suggest that the matrix viscoelasticity might influence the loading speed effects on the tensile properties of these green composite materials.

Abstract: The use of plasticizers usually has a beneficial effect on the ductile properties of polymers due to a reduction in the interaction of the polymer chains. As a result of this reduced interaction, there is also a reduction in the tensile strength of the material up to 20.3 MPa. To improve the interaction of polymer and plasticizer without affecting the ductility of the material, and potential migration, a reactive extrusion (REX) process is proposed in this research, by using several organic peroxides in poly(lactide)-dibutyl itaconate (DBI) plasticized formulations. Test specimens are obtained by extrusion and injection moulding and the overall mechanical properties, thermal degradation and biodegradation were measured. The tensile strength increased up to 25.1 MPa and with an elongation above 270%.

Abstract: This research article is focused on the structural, electronic, thermal, and vibrational properties of solid biopolymer electrolytes based on Agar-Agar and sodium hexafluorophosphate (NaPF₆) salt. Herein, the density functional theory (DFT) technique is used to investigate these properties. The structural analysis provides information about the interactions between Agar-Agar and NaPF₆ and hence interaction energy is analysed. Thermodynamic parameters such as Gibbs’ free energy (G), enthalpy (H), entropy (S), and specific heat (C_v) etc. are studied by frequency analysis at normal temperature pressure (NTP) of titled electrolytes. The chemical descriptors of the electrolytes have been studied using the molecular orbital theory (MOT). Molecular electrostatic potential surface (MEPS) demonstrates the three-dimensional molecular charge distribution and illustrates the electron-rich and deficit regions over the whole electrolyte system. Mulliken population analysis (MPA) gives the identification of intramolecular hydrogen bonding. The theoretical infrared (IR) study confirms the formation of the complex system between Agar-Agar and NaPF₆ salt. The overall DFT studies of sodium ion-based biopolymer electrolytes have better possibilities for safe sodium-ion batteries.

Abstract: In this study, fatigue property of green composite using unidirectional jute fiber sliver and poly (lactic acid) resin was investigated for a long term safety of sustainable structural materials. The fiber volume fraction of green composite was about10%. The green composite plate was fabricated by using jute fiber sliver/poly (lactic acid) resin prepreg. The molding method was vacuum compression molding method. The quasi-static tensile and fatigue tests of green composites were conducted under room temperature. The maximum number of cycle to failure was 10⁶ cycles. Fracture surfaces of green composites were observed after fatigue and static tensile tests. Following conclusions were obtained. The fatigue strength of green composite decreased with an increase of number of cycle. The fatigue strength at 10⁵ cycles of green composite was 50% of the tensile strength. From surface observation, the fiber pull-out in fracture surface of green composite were not found after quasi-static tensile and fatigue tests. Therefore, fatigue property of green composite using low addition amount of jute fiber sliver might be dominated by fatigue property of poly (lactic acid) resin.