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The utilization of natural fibers obtained from leather industrial wastes contributes to a circular economy and aids to the reduction in the usually high loadings of mineral flame-retardant additives employed to impart the flame retardancy in polymer systems. The present work investigates the relationship between viscoelastic properties and flame retardancy of thermoplastic starch multicomponent systems loaded with leather waste, aluminum trihydroxide used as flame-retardant additive, and bentonite clay. Different blending temperatures and rotational speeds during extrusion process are tested for the multicomponent systems. Rheological, morphological, flammability, thermal analysis, and tensile mechanical test are also used to characterize the obtained multicomponent systems. A detailed investigation of the viscoelastic properties through Han, Cole–Cole, and van Gurp–Palmen diagrams indicated that the fibers have to be well dispersed in the polymer matrix forming a network structure and that the material has to exhibit viscoelasticity to a moderate level, i.e., not too viscous and not too elastic as observed in the VGP diagram in order to impart the flame retardancy effect in the multicomponent system. These multicomponent systems with enhanced properties are a promising and sustainable alternative to traditional high-loaded flame-retardant systems taking advantage of the landfill disposal in local areas where leather wastes are a problem the great attention contributing to a circular economy. [ABSTRACT FROM AUTHOR]

Despite its popularity as a bio‐based biodegradable material, polylactic acid (PLA) has a number of shortcomings. Nevertheless, the combination of poly(butylene adipate co‐terephthalate) (PBAT) and thermoplastic starch (TPS) to enhance the mechanical properties of PLA was achieved through the utilisation of PLA/PBAT/TPS ternary composites, which were created through the calendering method. These composites exhibit advantageous characteristics, including high ductility, enhanced toughness, and biodegradability. The results of the water vapour permeability test indicate that the proportion of the material composition exhibiting the lowest value of water vapour permeability is 2.0571 g/m²·24h. The results of the water vapour transmission test demonstrate that the material generated by the composition ratio has the lowest water vapour transmission, indicating that the composite material blending effect is superior. The majority of current research employs nanocellulose as a substrate in PLA, with a paucity of studies investigating its use in PLA/PBAT/TPS composites. These composites are modified due to the notable divergence of nanocellulose from the hydrophobicity of the composite and its susceptibility to decomposition at elevated temperatures. This study establishes a foundation for future research in this field. [ABSTRACT FROM AUTHOR]

Starch is considered an ideal alternative to petroleum‐based plastics. However, the application of thermoplastic starch (TPS), which produced from cassava starch plasticized with glycerol, is limited by its hydrophilic, poor mechanical properties, and inadequate processability. In this study, dialdehyde starch (DAS) is used as crosslinker to modify TPS/poly(vinyl alcohol) (PVA), and DAS crosslinked cassava starch/PVA blends are fabricated by melt mixing method. Studies on the molecular structure of DAS crosslinked cassava starch/PVA blend indicate that the addition of DAS enhances the intermolecular interactions between cassava starch and PVA, resulting in the formation of a dense internal structure. The plasticizing torque and equilibrium torque of crosslinked cassava starch/PVA blends are increased and the tensile strength reaches 3.60 MPa, an improvement of 186% compared with TPS. Additionally, the water contact angle increases from 87.8° to 119.6° after modification. Compared with other crosslinkers, DAS has obvious advantages, making the DAS crosslinked cassava starch/PVA blend a biodegradable material with excellent properties and promising application prospects. [ABSTRACT FROM AUTHOR]

The water absorption characteristics of thermoplastic starch (TPS) reveal its ability to interact with and absorb water, influencing its overall performance in various applications. The introduction of aloe vera (AV) gel into the TPS polymeric matrix film has proven beneficial in enhancing tensile strength but a notable deficiency is observed in lowering water absorption percentage. Therefore, this paper aims to reduce the water absorption of the TPS30AV polymer matrix film by utilizing polyethylene (PE) without reducing the tensile strength performance of the TPS30AV film. The TPS30AV film was produced using melt-blending and hot-press techniques. Six samples were presented consisting of a control film (TPS30AV) and TPS30AV film with different concentrations of PE resins (5%, 10%, 20%, 30%, and 40%). The film's performance was assessed by examining its mechanical properties, water absorption, and water solubility. The finding shows that TPS30AV with 40% PE has the highest improvement in water absorption percentage which reduces from 309.86% to 34.16% but a tremendous decrement in tensile strength performance. However, TPS30AV with 10% PE has the highest tensile strength, 9.65 MPa with a 20.99% improvement in water absorption reduction. The properties obtained for TPS30AV10PE were also good in Young's modulus and water solubility percentage. It shows that the film formulated is comparable with previous studies, and improvement has been achieved. As a conclusion, adding PE improved the polymeric structure of TPS30AV and can be used as a biodegradable food-packaging film. [ABSTRACT FROM AUTHOR]

This study focused on the development and optimization of thermoplastic starch (TPS) and poly(butylene adipate‐co‐terephthalate) (PBAT) biobased active packaging films by incorporation with grape seed oil, alpha‐tocopherol, and rice husk. In the compound and film production step during extrusion for biobased active packaging film two variables, the antioxidant substance concentration (Grape seed oil, 0.5–4%; alpha‐tocopherol, 0.5–4%; rice husk, 1–5%), TPS concentration (60–90%) were optimized through response surface methodology (RSM) for highest tensile strength (MPa) and antioxidant activity (%) as responses. Among the resulting films, samples containing grape seed oil in particular exhibited an optimal balance, showcasing robust mechanical properties alongside potent antioxidant characteristics. Comprehensive analyses encompassing thickness, density, color, opacity, FTIR spectroscopy, total phenolic content, and energy consumption were conducted to assess the films' viability for potential deployment within the food industry. Based on the findings, it was determined that these biobased active packaging films made of TPS/PBAT held promise in safeguarding food products. [ABSTRACT FROM AUTHOR]

To investigate the impact of plasticizer functional groups on starch plasticization, three distinct plasticizers were selected in this study: ethylene glycol (EG), ethylenediamine (EDA), and ethylenebisformamide (EBF). Three models of the plasticizer/starch system were constructed using molecular dynamics (MD) simulations, and the analysis encompassed the computation of mean square displacement (MSD), radial distribution function (RDF), and hydrogen bonding energy for each system. Additionally, the proportions of simulation were used to prepare thermoplastic starch films, which were subsequently subjected to examinations such as DSC, XRD, FT-IR, SEM, and mechanical property testing. Comparative analysis of the simulation data from the three systems and the properties of the manufactured thermoplastic starch (TPS) established that the diverse functional groups of plasticizers significantly influenced starch plasticization. In different plasticizer functional group types, it was observed that hydroxyl groups in EG and amino groups in EDA predominantly form hydrogen bonds with hydroxyl groups in starch molecular chain. In contrast, amide groups in EBF can establish hydrogen bonds not only with hydroxyl groups of starch but also with ether bonds on the starch main chain, thereby resulting in more effective starch plasticization. [ABSTRACT FROM AUTHOR]

This study aimed to enhance compatibility and thermal stability between thermoplastic starch (TPS) and polylactic acid (PLA) by incorporating citric acid-grafted starch (CA–Starch) at different concentrations (1 and 5%) with varying degrees of substitution for starch derived from sweet potatoes and yams (DY). Blends were produced using a constant TPS/PLA weight ratio of 60:40, both with and without a compatibilizer. The blending process was carried out using a torque rheometer under two distinct conditions. The results exhibited reduced particle sizes in TPS60/PLA40/CA–Starch blends, as evidenced by SEM images displaying improved interaction and smoother surfaces. Significantly, one of the properties that experienced substantial improvement was the compatibility between TPS and PLA, as indicated by reduced phase segregation within the blends. This improvement manifested in enhanced surface morphology, smaller particle sizes, and greater homogeneity in the blends. Additionally, an enhancement in thermal properties, particularly thermal stability, was observed with higher CA content. This study underscores that the incorporation of CA–Starch not only enhances compatibility but also improves thermal stability in TPS60/PLA40 blends, offering potential for the development of biocompatible materials with superior performance. [ABSTRACT FROM AUTHOR]

Thermoplastic starch (TPS) has gained considerable attention during the last few years in developing starch-based biodegradable food packaging materials or edible coatings due to its high availability and low cost. TPS is manufactured from starch plasticized with food-grade plasticizers, making it suitable for food contact applications. In addition, TPS is bio-based and biodegradable, which, from an environmental perspective, closes the circle of the circular economy. However, the industrial application of TPS is somewhat limited due to its poor mechanical performance and low water resistance. However, the low water resistance could increase the water sensitivity of TPS, which could be advantageous for coating application or food encapsulation. The present work aims to tailor the water sensitivity of TPS by adding peach gum polysaccharide to obtain water-soluble films. With this aim, peach gum polysaccharide (PGP) was extracted from peach gum (PG) using the thermal hydrolysis method. Films of TPS-PG and TPS-PGP were prepared and characterized by their water sensitivity and mechanical, microstructural, and thermal properties. The results show that PGP allows the obtaining of films with water sensitivities higher than 70% but also improves TPS elongation at break, making the material more suitable for application as film. [ABSTRACT FROM AUTHOR]

Abstract In this study, thermoplastic starch (TPS) biofilms were developed using starch isolated from the seeds of Melicoccus bijugatus (huaya) and reinforced with bentonite clays at concentrations of 1%, 3%, and 5% by weight. Novelty of this research lies in utilizing a non-conventional starch source and enhancing properties of TPS through clay reinforcement. FTIR analysis verified bentonite’s nature of clays, while SEM analysis provided insights into morphology and agglomeration behavior. Key findings include a notable increase in biofilm thickness and elastic modulus with higher clay content. Specifically, tensile strength of biofilms improved from 2.5 MPa for pure TPS to 5.0 MPa with 5% clay reinforcement. The elastic modulus increased from 25 MPa (TPS) to 60 MPa (5% clay). Thermal stability also showed enhancement, with initial degradation temperature increasing from 110 °C for pure TPS to 130 °C for TPS with 5% clay. Water vapor permeability (WVP) tests demonstrated a decrease in WVP values from 4.11 × 10−10 g m−1 s−1 Pa−1 for pure TPS to 2.09 × 10−10 g m−1 s−1·Pa−1 for TPS with 5% clay, indicating a significant barrier effect due to clay dispersion. These results suggest that biofilms based on huaya starch and reinforced with bentonite clay have considerable potential for sustainable food packaging applications, offering enhanced mechanical and barrier properties.

Abstract This research aims to formulate biobased and biodegradable packaging films with high toughness and fast home-compost biodegradation using ternary blends of polylactic acid (PLA), Para rubber (NR), and thermoplastic starch (TPS) through blown-film extrusion. The TPS content in this work ranges from 5 to 20 wt%, while the PLA: NR ratio is fixed at 70:30. At this PLA: NR ratio, the blend with 10 wt% TPS (PNT10) exhibited the highest % elongation at break and tensile toughness. Peroxide radical initiator was investigated as a potential additive for improving the properties of the ternary blend. Our binary interaction study indicated that peroxide initiated grafting reactions of PLA–NR and NR–TPS pairs, while no grafting occurred between PLA and TPS. In ternary blends, the highest peroxide content (0.5 wt%) increased the % elongation at break up to 120%, with the tensile toughness reaching 7255 MJ/m3. The improved compatibility induced by peroxide addition was supported by enhanced dispersion of TPS in the PLA/NR matrices. Results from the room-temperature soil burial test indicated that the presence of TPS could significantly accelerate the home-compost degradation of PNT films compared to films produced from neat PLA and PLA/NR. This suggests its potential as both a cost reducer and a biodegradation accelerator.

Thermoplastic starch (TPS) has gained considerable attention during the last few years in developing starch-based biodegradable food packaging materials or edible coatings due to its high availability and low cost. TPS is manufactured from starch plasticized with food-grade plasticizers, making it suitable for food contact applications. In addition, TPS is bio-based and biodegradable, which, from an environmental perspective, closes the circle of the circular economy. However, the industrial application of TPS is somewhat limited due to its poor mechanical performance and low water resistance. However, the low water resistance could increase the water sensitivity of TPS, which could be advantageous for coating application or food encapsulation. The present work aims to tailor the water sensitivity of TPS by adding peach gum polysaccharide to obtain water-soluble films. With this aim, peach gum polysaccharide (PGP) was extracted from peach gum (PG) using the thermal hydrolysis method. Films of TPS-PG and TPS-PGP were prepared and characterized by their water sensitivity and mechanical, microstructural, and thermal properties. The results show that PGP allows the obtaining of films with water sensitivities higher than 70% but also improves TPS elongation at break, making the material more suitable for application as film.

In this study, thermoplastic starch (TPS) biofilms were developed using starch isolated from the seeds of Melicoccus bijugatus (huaya) and reinforced with bentonite clays at concentrations of 1%, 3%, and 5% by weight. Novelty of this research lies in utilizing a non-conventional starch source and enhancing properties of TPS through clay reinforcement. FTIR analysis verified bentonite's nature of clays, while SEM analysis provided insights into morphology and agglomeration behavior. Key findings include a notable increase in biofilm thickness and elastic modulus with higher clay content. Specifically, tensile strength of biofilms improved from 2.5 MPa for pure TPS to 5.0 MPa with 5% clay reinforcement. The elastic modulus increased from 25 MPa (TPS) to 60 MPa (5% clay). Thermal stability also showed enhancement, with initial degradation temperature increasing from 110 °C for pure TPS to 130 °C for TPS with 5% clay. Water vapor permeability (WVP) tests demonstrated a decrease in WVP values from 4.11 × 10−10 g m−1 s−1 Pa−1 for pure TPS to 2.09 × 10−10 g m−1 s−1·Pa−1 for TPS with 5% clay, indicating a significant barrier effect due to clay dispersion. These results suggest that biofilms based on huaya starch and reinforced with bentonite clay have considerable potential for sustainable food packaging applications, offering enhanced mechanical and barrier properties. [ABSTRACT FROM AUTHOR]

Dynamic mechanical spectroscopy is a common analysis for polymers. Rectangular specimens are usually used for measurement in the solid state due to their easy designing. However, in reason of the non‐symmetric shape of sample, rectangular specimens do not experience linear stress on their all body, leading to overestimation of shear modulus. Corrections are required to determine the right shear modulus. In this present work, straight shear modulus determination is carried out using specimens with a cylindrical shape. The reliability of the technique is described on a biosourced polymer materials made of thermoplastic starch, plasticized by glycerol, choline chloride/urea mixture (ChCl/U), 1‐ethyl‐3‐methylimidazolium chloride ([EMIM]Cl) and 1‐ethyl‐3‐imidazolium acetate ([EMIM]Ac). The technique is shown to be particularly interesting to avoid any additional shaping of the specimens prior to measurements, that can be detrimental to their properties (evaporation, degradation). A comparison between cylinder and rectangular specimen has also been made to illustrate the interest of cylinder clamping on biosourced polymer material. [ABSTRACT FROM AUTHOR]

Proper waste sorting is crucial for biodegradable plastics (BDPs) recycling, whose global production is increasing dynamically. BDPs can be sorted using near-infrared (NIR) sorting, but little research is available about the effect of surface contamination on their NIR spectrum, which affects their sortability. As BDPs are often heavily contaminated with food waste, understanding the effect of surface contamination is necessary. This paper reports on a study on the influence of artificially induced surface contamination using food waste and contamination from packaging waste, biowaste, and residual waste on the BDP spectra. In artificially contaminated samples, the absorption bands (ADs) changed due to the presence of moisture (1352–1424 nm) and fatty acids (1223 nm). In real-world contaminated samples, biowaste samples were most affected by contamination followed by residual waste, both having altered ADs at 1352–1424 nm (moisture). The packaging waste-contaminated sample spectra closely followed those of clean and washed samples, with a change in the intensity of ADs. Accordingly, two approaches could be followed in sorting: (i) affected wavelength ranges could be omitted, or (ii) contaminated samples could be used for optimizing the NIR database. Thus, surface contamination affected the spectra, and knowing the wavelength ranges containing this effect could be used to optimize the NIR database and improve BDP sorting. [ABSTRACT FROM AUTHOR]

The present study investigates the effects of different isolation methods on the physicochemical and mechanical properties of Melicoccus bijugatus Jacq. thermoplastic starch (TPS). Three isolation methods were used: extraction with sodium bisulfite (M1), with distilled water (M2) and by an acid process (M3). The research focused on studying the effect of the insulation method on the structural integrity and properties of the TPS. The study revealed that the isolation technique significantly influences the morphology and size of starch granules, as demonstrated in SEM analysis. FTIR spectra identified variations in hydrogen bond formation and molecular structure of starch. The TGA analyses showed differences in the thermal stability of the TPS, depending on the insulation method, with the M3 process providing the greatest thermal stability. Furthermore, DSC analysis showed variances in gelatinization temperature and gelatinization enthalpy between the different TPS materials. Regarding the mechanical properties, it was found that the insulation method affects the tensile strength and the elastic modulus of the TPS. Mechanical test results verified that the stiffness and flexibility of the TPS are directly affected by the insulation process. This research provides information on the effect that, the starch isolation methods proposed, possesses on the properties of Melicoccus TPS bijugatus Jacq. These findings are fundamental to optimize the application of TPS in various areas, considering the specific characteristics of each isolation method. [ABSTRACT FROM AUTHOR]

In this study, the impact of bioplastic design on anaerobic digestion for biogas production was investigated. This research aims to facilitate the integration of bioplastics into a circular economy, which is why our study proposes considering not only aspects related to their degradation in the formulation but also ensuring efficient behavior in anaerobic digestion plants. Thermoplastic starch (TPS) samples, derived from different starch sources and formulated with varying concentrations of calcium carbonate and thicknesses, were subjected to anaerobic digestion tests. Three key parameters were explored: the influence of filler concentration, the effect of sample thickness, and the role of starch origin. Biogas production and kinetics were assessed using biochemical methane potential (BMP) tests. The results reveal that calcium carbonate concentration negatively influenced the methane production rate, reaching 30 NmL/gVS/day for the filler-free sample, highlighting the importance of understanding filler effects on anaerobic digestion. Additionally, thicker samples exhibited slower biogas production, with a rate of 25 NmL/gVS/day compared to 30 NmL/gVS/day for the thinnest sample, emphasizing the relevance of sample thickness in influencing digestion kinetics. The starch origin did not yield significant differences in biogas production, providing valuable insights into the feasibility of using diverse starch sources in bioplastic formulations. This study enhances our understanding of bioplastic behavior during anaerobic digestion, offering essential insights for optimizing waste management strategies and advancing circular economy practices. [ABSTRACT FROM AUTHOR]

This research aims to formulate biobased and biodegradable packaging films with high toughness and fast home-compost biodegradation using ternary blends of polylactic acid (PLA), Para rubber (NR), and thermoplastic starch (TPS) through blown-film extrusion. The TPS content in this work ranges from 5 to 20 wt%, while the PLA: NR ratio is fixed at 70:30. At this PLA: NR ratio, the blend with 10 wt% TPS (PNT10) exhibited the highest % elongation at break and tensile toughness. Peroxide radical initiator was investigated as a potential additive for improving the properties of the ternary blend. Our binary interaction study indicated that peroxide initiated grafting reactions of PLA–NR and NR–TPS pairs, while no grafting occurred between PLA and TPS. In ternary blends, the highest peroxide content (0.5 wt%) increased the % elongation at break up to 120%, with the tensile toughness reaching 7255 MJ/m3. The improved compatibility induced by peroxide addition was supported by enhanced dispersion of TPS in the PLA/NR matrices. Results from the room-temperature soil burial test indicated that the presence of TPS could significantly accelerate the home-compost degradation of PNT films compared to films produced from neat PLA and PLA/NR. This suggests its potential as both a cost reducer and a biodegradation accelerator. [ABSTRACT FROM AUTHOR]

Polybutylene adipate-terephthalate/thermoplastic starch/organic montmorillonite (PBAT/TPS/OMMT) biodegradable materials have attracted wide attention in recent years. However, the conventional twin-screw processing technique leads to material degradation and makes it difficult to achieve good stripping of OMMT. In order to improve its mechanical properties, PBAT was chain expansion modified by ADR-4468, and PBAT/TPS/OMMT containing different contents of modified PBAT (A-PBAT) were prepared by melt extrusion using a perturbation ring dual-speed twin-screw extruder, and the effects of different contents of A-PBAT on the microstructure, rheological properties, compatibility, water absorption and mechanical properties of the composites were analyzed. The results showed that the chain extender effectively improved the mechanical properties of PBAT, and the dual-speed twin-screw could strip OMMT well and make TPS uniformly dispersed and distributed in PBAT. With the increase of A-PBAT content, TPS transforms from continuous phase to dispersed phase, the water absorption of the composite material gradually decreases, and the tensile strength gradually increases, reaching its maximum at a mass fraction of 60% A-PBAT, with a slight decrease in elongation at break. 20% A-PBAT can effectively improve the compatibility between TPS and PBAT. [ABSTRACT FROM AUTHOR]

This research aims to study the thermal and mechanical properties of biodegradable thermoplastic cassava starch (TPCS) reinforced with various sizes of coconut husk fibre (CHF). The range of fibre sizes used was 125, 200, and 300 µm. These CHFs were integrated into a thermoplastic cassava starch matrix to make bio-composites. After integrating all components, the bio-composites were hot-pressed at 155°C for 60 minutes to produce thermoplastic sheets. Tensile and flexural tests were carried out to examine the mechanical characteristics of TPCS/CHF composites. The samples were also characterised using Thermogravimetric Analysis (TGA), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). The findings demonstrated that a smaller 125 µm CHF improved the mechanical properties higher than other fibre sizes. Fibre with 300 μm showed more voids, which led to lower material strength. TGA results showed that 300 μm fibres enhanced the crystallinity and thermal stability of the material. FTIR and TGA showed that CHF incorporation increased intermolecular interactions and thermal stability. Overall, a smaller fibre size of 125 μm showed a better reinforcement effect than the larger fibre sizes, which enhanced the materials' tensile and flexural properties. This study demonstrated that modified TPCS/CHF has shown enhanced functionality than neat TPCS. [ABSTRACT FROM AUTHOR]

Highlights The study presents the ideal distribution of graphene nanoplatelets (GNP) within the thermoplastic starch (TPS) matrix significantly elevated the thermal and electrical conductivities, as well as the electrochemical efficiency of the biocomposites. Additionally, the incorporation of GNP resulted in an increased thermal stability for the TPS, as indicated by the elevated temperatures required for maximum degradation. The biocomposites exhibited a self‐aligned layered structure, creating conductive pathways and enhancing electron conduction. An electrical conductivity increased as the concentration of GNP increased, with the highest conductivity observed on the top and bottom surface with the value of 4.23 × 10−7 S/m and 3.92 × 10−6 S/m when 12 wt% of GNP was added. The presence of hydroxyl groups in TPS facilitated the formation of hydrogen bonds with GNP, preventing GNP from stacking and forming a more uniform conductive network within the film. The addition of 15 wt% GNP also improved the capacitive performance of the TPS matrix, as evidenced by higher current responses and larger quasi‐rectangular areas in the cyclic voltammetry curves compared to neat TPS. The Nyquist plots which are illustrated impedance data showed that the TPS film with 12 wt% GNP exhibits the smallest semicircle, indicating the highest conductivity which is suggested that GNP improves charge transfer compared to pure TPS. Optimal dispersion of GNP enhanced the biocomposite's properties. The electrical conductivity increases with the GNP content until 12 wt%. TPS/GNP self‐aligned layered improved conduction and capacitive behavior. GNP improved thermal stability by restricting polymer chain movement. Electrochemical impedance shows improved properties of TPS/GNP. [ABSTRACT FROM AUTHOR]

Nanocellulose fibres are known to enhance the mechanical properties of biopolymers when added as a filler. Nanocellulose irreversibly agglomerates upon drying and is therefore sold as an aqueous gel or suspension, increasing shipping cost and limiting application. This work studied the utility of xanthan gum as a dispersant aid for dried nanocellulose fibres. At levels as low as 15% xanthan gum addition, based on the mass of nanocellulose, prior to drying, agglomeration was significantly decreased. Mild shear rates could disperse the dried nanocellulose to a similar degree as ultrasonication when xanthan gum was present. Several complementary techniques, such as rheology, turbidimetry, and SEM- and TEM-imaging, proved that the native nanocellulose properties could be recovered after drying. Xanthan gum and nanocellulose, when incorporated into thermoplastic starch, showed a synergistic effect regarding the increase in tensile strength of the resultant biopolymer film. The addition of previously dried nanocellulose/xanthan, in a 4:1 ratio, to thermoplastic starch at a starch-cellulose ratio of 20:1, increased the tensile strength from 5.4 to 23.0 MPa. The ability to produce a dispersible and dry nanocellulose product that retains its properties has clear commercial benefits. [ABSTRACT FROM AUTHOR]

Currently, petroleum-derived plastics are widely used despite the disadvantage of their long degradation time. Natural polymers, however, can be used as alternatives to overcome this obstacle, particularly cornstarch. The tensile properties of cornstarch films can be improved by adding plant-derived nanofibers. Sisal (Agave sisalana), a very common low-cost species in Brazil, can be used to obtain plant nanofibers. The goal of this study was to obtain sisal nanofibers using low concentrations of sulfuric acid to produce thermoplastic starch nanocomposite films. The films were produced by a casting technique using commercial corn starch, glycerol, and sisal nanofibers, accomplished by acid hydrolysis. The effects of glycerol and sisal nanofiber content on the tensile mechanical properties of the nanocomposites were investigated. Transmission electron microscopy findings demonstrated that the lowest concentration of sulfuric acid produced fibers with nanometric dimensions related to the concentrations used. X-ray diffraction revealed that the untreated fibers and fibers subjected to acid hydrolysis exhibited a crystallinity index of 61.06 and 84.44%, respectively. When the glycerol and nanofiber contents were 28 and 1%, respectively, the tensile stress and elongation were 8.02 MPa and 3.4%. In general, nanocomposites reinforced with sisal nanofibers showed lower tensile stress and higher elongation than matrices without nanofibers did. These results were attributed to the inefficient dispersion of the nanofibers in the polymer matrix. Our findings demonstrate the potential of corn starch nanocomposite films in the packaging industry. [ABSTRACT FROM AUTHOR]

When the cocoa pod husk (CPH) is used and processed, two types of flour were obtained and can be differentiated by particle size, fine flour (FFCH), and coarse flour (CFCH) and can be used as a possible reinforcement for the development of bio-based composite materials. Each flour was obtained from chopping, drying by forced convection, milling by blades, and sieving using the 100 mesh/bottom according to the Tyler series. Their physicochemical, thermal, and structural characterization made it possible to identify the lower presence of lignin and higher proportions of cellulose and pectin in FFCH. Based on the properties identified in FFCH, it was included in the processing of thermoplastic starch (TPS) from the plantain pulp (Musa paradisiaca) and its respective bio-based composite material using plantain peel short fiber (PPSF) as a reinforcing agent using the following sequence of processing techniques: extrusion, internal mixing, and compression molding. The influence of FFCH contributed to the increase in ultimate tensile strength (7.59 MPa) and higher matrix–reinforcement interaction when obtaining the freshly processed composite material (day 0) when compared to the bio-based composite material with higher FCP content (30%) in the absence of FFCH. As for the disadvantages of FFCH, reduced thermal stability (323.57 to 300.47 °C) and losses in ultimate tensile strength (0.73 MPa) and modulus of elasticity (142.53 to 26.17 MPa) during storage progress were identified. In the case of TPS, the strengthening action of FFCH was not evident. Finally, the use of CFCH was not considered for the elaboration of the bio-based composite material because it reached a higher lignin content than FFCH, which was expected to decrease its affinity with the TPS matrix, resulting in lower mechanical properties in the material. [ABSTRACT FROM AUTHOR]

The development of active food packaging is desirable for food safety and to avoid food loss and waste. In this work, we developed antioxidant bilayer films combining extrusion and electrospinning techniques. These films consisted of a first layer of thermoplastic cornstarch (TPS), incorporated with microcrystalline cellulose (MCC). The second layer consisted of gallic acid (GA) encapsulated at different concentrations in 1:1 chitosan/poly(ethylene-co-vinyl alcohol) (CS/EVOH) nanofibers. This layer was directly electrospun onto the TPS/MCC film. The morphological, structural, wettability, permeability to oxygen, and antioxidant properties were investigated for the first layer and the bilayer films. Water contact angle measurements revealed the hydrophobic nature of the first layer (θ0 = 100.6°). The oxygen permeability (OP) was accessed through the peroxide value (PV) of canola oil, kept in containers covered by the films. PV varied from 66.6 meq/kg for the TPS/MCC layer to 60.5 meq/kg for a bilayer film. Intermolecular hydrogen bonds, mediated by GA, contributed slightly to improving the mechanical strength of the bilayer films. The bilayer film incorporated with GA at 15.0% reached a radical scavenging activity against the DPPH radical of (903.8 ± 62.2) μmol.L−1.Eq. Trolox.g−1. This result proved the effectiveness of the GA nanoencapsulation strategy. [ABSTRACT FROM AUTHOR]

Bioplastic films with excellent barrier properties were successfully prepared from poly(butylene adipate‐co‐terephthalate) (PBAT), thermoplastic starch (TPS), and poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate) (PHBHHx). The rheological, mechanical, barrier, dynamic mechanical properties, and microstructure of the PBAT/TPS/PHBHHx films were studied. The transition of the continuous phase in the blend significantly affects the properties of the films. The increase in PHBHHx content results in its transition from a dispersed phase to a continuous phase. This phase transition, along with the consequent increase in the crystallinity of PHBHHx, greatly enhances the barrier properties of the film. The percentage crystalline degree of PHBHHx increased from 10.9% to 25.1% with increasing PHBHHx content from 0% to 50%. The film containing 50% PHBHHx showed a significant decrease in both water vapor permeability (WVP) and oxygen permeability (OP) by 75.1% and 69.6%, respectively. It found that the film containing 50% PHBHHx exhibited a decrease of elongation at break from 505% to less than 10% but an unusual increase of tensile strength after a 72‐hour aging test, which is different from PBAT and PBAT/TPS films. However, this indicates that the extensibility of PHBHHx is more susceptible to the effects of aging test, leading to the rearrangement of polymer chains from disordered to ordered morphology. [ABSTRACT FROM AUTHOR]

This research highlights the importance of addressing bioplastic contamination in recycling processes to ensure the quality of recycled material and move towards a more sustainable circular economy. Polyethylene (PE) is a conventional plastic commonly used in packaging for which large amounts of waste are produced; therefore, PE is generally recycled and has an established recycling process. However, the contamination of biodegradable polymers in the PE waste stream could impact recycling. This study, therefore, focuses on polyethylene (PE) that has been polluted with a commercial thermoplastic starch polymer (TPS), as both materials are used to produce plastic films and bags, so cross-contamination is very likely to occur in waste separation. To achieve this, recycled PE was blended with small quantities of the commercial TPS and processed through melt extrusion and injection molding, and it was further characterized. The results indicate that the PE-TPS blend lacks miscibility, evidenced by deteriorated microstructure and mechanical properties. In addition, the presence of the commercial TPS affects the thermal stability, oxidation, and color of the recycled PE. [ABSTRACT FROM AUTHOR]

The development of active food packaging is desirable for food safety and to avoid food loss and waste. In this work, we developed antioxidant bilayer films combining extrusion and electrospinning techniques. These films consisted of a first layer of thermoplastic cornstarch (TPS), incorporated with microcrystalline cellulose (MCC). The second layer consisted of gallic acid (GA) encapsulated at different concentrations in 1:1 chitosan/poly(ethylene-co-vinyl alcohol) (CS/EVOH) nanofibers. This layer was directly electrospun onto the TPS/MCC film. The morphological, structural, wettability, permeability to oxygen, and antioxidant properties were investigated for the first layer and the bilayer films. Water contact angle measurements revealed the hydrophobic nature of the first layer (θ0 = 100.6°). The oxygen permeability (OP) was accessed through the peroxide value (PV) of canola oil, kept in containers covered by the films. PV varied from 66.6 meq/kg for the TPS/MCC layer to 60.5 meq/kg for a bilayer film. Intermolecular hydrogen bonds, mediated by GA, contributed slightly to improving the mechanical strength of the bilayer films. The bilayer film incorporated with GA at 15.0% reached a radical scavenging activity against the DPPH radical of (903.8 ± 62.2) μmol.L−1.Eq. Trolox.g−1. This result proved the effectiveness of the GA nanoencapsulation strategy.

As changes in the melting behavior of starch in the extruder affect the physical properties of the extrudate. exploring the melting behavior during starch extrusion is of great significant for the production of ideal thermoplastic starch-based materials. Effects of different extrusion temperatures (60, 70, 80, 90 and 100 ℃) on the structure and physicochemical properties of corn starch were investigated. The results showed that under high temperature and mechanical shear, the starch granules were fragmented and the granule size was reduced. The hydrogen bonds within starch molecules were broken, which made starch easier to bind with water molecules, to improve the hydration properties of thermoplastic starch (TPS). As the temperature increased, the content of amylose increased, and the relative crystallinity (RC) and double-helix order (DO) decreased, indicating that the long-range and short-range ordered structures of corn starch were destroyed during heating. The high temperature treatment of the extruder reduced the enthalpy of TPS and destroyed the ability of starch paste to form a gel network. The samples had a weak gelation behavior, and the rigidity and elasticity were weakened. In conclusion, the temperature of twin-screw extrusion changed the starch particle structure, crystalline structure, hydration and rheological properties to different degrees. This study has provided theoretical basis and new ideas for extruding high quality thermoplastic starch materials.

Thin films with pH sensitivity have been a trendsetter in the current research scenario. Edible films for packaging are comparatively newer ones, where the study uses conventional food materials as a source or precursor to fabricate the films. Starch(S) is one such material that is not much exploited in packaging and pH sensing. Here, the study presents the preparation of a new type of sensitive, intelligent film from starch‐chitin(CHN) composites and adds the anthocyanin pigment extracted from the Butterfly Pea flower (BPE). The combination films are much more sensitive to ammonia and formalin and thus suggested for the detection of adulteration in fish. All the films (S, S/BPE, S/CHN, and S/BPE/CHN) are fabricated by the solution casting method. The addition of 10 wt% CHN results in the enhancement of the thermal and mechanical properties of pH indicator films. Owing to the presence of anthocyanin pigment, the films can change their color changes in pH. The developed starch‐based intelligent films display wide color differences from bright red to green over the 1–12 pH range, which is discriminated by the naked eye. [ABSTRACT FROM AUTHOR]

In this study, starch was modified with different amounts of boric acid, and the degree of substitution of the synthesized compounds at different temperatures and times was determined by Fourier transform infrared (FTIR) and titration methods. The degrees of substitution in both methods showed similar tendency. Optimum conditions were determined, and thermoplastic starch (TPS) and boric acid (B) films were prepared by casting method using glycerol as plasticizer. The morphological properties of the films were studied by scanning electron microscope‐energy dispersive spectrometry (SEM‐EDS). According to the FTIR results, it was observed that the BO and BOC stretching vibrations increased when the amount of boric acid increased. The tensile strength, water barrier (swelling capacity, solubility, and water vapor permeability), and optical properties of samples were investigated. The swelling capacity, solubility, and water vapor permeability of the films decreased with the addition of 0.5% boric acid to the starch, but the highest tensile strength was achieved. The tensile strength for TPSB0.5% increased compared to control group TPS. In addition, the film showed the highest transparency. Thermoplastic film containing 0.5% boric acid can be used as a packaging material due to its improved mechanical and water barrier. Highlights: The thermoplastic starch and boric acid composite were successfully produced.The presence of boric acid was confirmed by energy dispersive spectrometry (EDS).The degree of substitution was determined by two different methods.Transparency increased with the addition of boric acid.Tensile strength improved with boric acid content. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to develop novel biocomposites with biocidal properties in microorganisms, with enhanced mechanical strength and hydrophobicity as well as with increased biodegradation rates. The main idea and the novelty of this work was to use cross-linking compounds and, at the same time, biocidal compounds—natural compounds of plant origin with biocidal properties. The authors assumed that the modification of flax fiber by natural plant compound will reduce the hydrophilicity of novel biocompositie. Biopolymer based on thermoplastic starch reinforced with flax fibres modified with tannic acid (TA) was prepared by extrusion and injection molding processes. The effects of TA modification on the mechanical and structural properties of biocomposites were analyzed through DMA, tensile tests, DSC, and TG. The biocidal and wettability properties of the biocomposites were investigated. The article also discusses the outcomes of research conducted on the structural characteristics and rates of the biodegradation of biocomposites. [ABSTRACT FROM AUTHOR]

Polylactic-acid–starch-based polymer composite (PLA/TPS) has good thermal stability for biocomposites. However, the physical and mechanical properties of PLA/TPS do not meet the standards. It needed additives to enhance its physical and mechanical properties. The aim was to improve the physical and mechanical properties of PLA/thermoplastic starch using sucrose. In addition, this study evaluated the enhancement of thermal properties of PLA/thermoplastic starch using sucrose. This study used sucrose as an additive to enhance the PLA/TPS composite. The addition of sucrose inhibits the degradation of biocomposites. This means that thermal stability increases. The thermal stability increased because the degree of crystallinity increased with the addition of sucrose, which was also proven in the XRD result. The addition of sucrose caused the morphology of the biocomposite to have pores. The FESEM results showed that biocomposites with the addition of sucrose had pores and gaps. These gaps result from low adhesion between polymers, causing a decrease in the mechanical and physical properties of the sample. Based on the FTIR spectra, biocomposite PLA/TPS blends with the addition of sucrose still have many hydroxyl groups that will lead to attracting other molecules or ions, such as oxygen or water. This phenomenon affects the physical and mechanical properties of materials. The physical and mechanical properties increased with sucrose addition. The best composite was prepared using 3% sucrose. This is because sucrose has a crystalline structure that affects the properties of biocomposites. However, the addition of 3% sucrose was not as effective as that of neat PLA. [ABSTRACT FROM AUTHOR]

Thermoplastic foams made from petrochemical polymers are commonly commercialized in the market, which, due to their chemical nature, require hundreds of years to degrade and therefore end up accumulating and polluting the environment. Therefore, the present research sought to develop a biodegradable foam from thermoplastic cassava starch, biodegradable polyester, and wheat gluten. Initially, an extreme vertex blend design was run, which comprised 60 to 70% thermoplastic starch (TPS), 30 to 40% biodegradable polyester, and 0 to 5% wheat gluten, the foam was obtained by extrusion and evaluated for expansion rate, bulk density, damping index, and morphology. A thin layer of rubber latex was applied to the foamed material with the most outstanding properties in order to reduce moisture adsorption, and its biodegradability was also evaluated. The results indicated that with the addition of 70% TPS, 30% polyester, and 0% wheat gluten, it was possible to obtain by extrusion a flexible thermoplastic foam with high radial expansion rate and low bulk density. Impregnation of the foam with natural rubber latex created an impermeable layer that helped to decrease moisture adsorption; however, there was an increase in compressibility. Also, it was found that this foam met the biodegradability condition since it presented a percentage of mineralization in relative terms of 97.59% in less than 180 days. [ABSTRACT FROM AUTHOR]

A high content of water is needed in traditional thermoplastic starch (TPS) processing to plasticize the starch and facilitate the processing, which leads to relatively low strength and modulus of the products and causes the issue of product aging partially due to the gradual water loss over time. In this work, based on the results from our previous study on lignin and cellulose nanofibril-reinforced TPS composites, a low content of citric acid (<0.5 wt%) was used to replace all the added water in the prior study (∼20 wt%). Citric acid demonstrated a much stronger viscosity-reducing effect than water and enabled composite processing at a very low acid content. The resultant nanocomposites exhibited much higher strength and modulus than those containing 20 wt% water as the processing aid. Fourier transform infrared spectrometry (FTIR) results showed strong interactions between the polar groups of starch and other ingredients. Scanning electron microscopy (SEM) photos indicated the disappearance of the two-phase "sea-island" morphology, suggesting the strong compatibilization effect of the acid. To lower the cost of the nanocomposites, we further replaced the starch and zein (an expensive biopolymer) components in the original composites with low-cost cornmeal. The new nanocomposites with cornmeal as the major ingredient exhibited similar processability and mechanical properties. With its low cost and high properties, this new type of agricultural byproduct-based nanocomposites is expected to be a promising material to replace synthetic polymers in many applications. [ABSTRACT FROM AUTHOR]

Copyright of Polish Technical Review is the property of Wydawnictwo SIGMA-NOT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study focuses on enhancing the mechanical and thermal properties of thermoplastic starch (TPS) and natural rubber (NR) blends by incorporating polyethylene glycol (PEG2000) and various types of modified natural rubbers, including epoxidized natural rubber (ENR50), poly (methyl methacrylate)-grafted natural rubber (NR-g-PMMA), and poly (butyl methacrylate)-grafted natural rubber (NR-g-PBMA). The influence of the TPS/NR blend ratio, PEG content, and type of modified NR on the properties of the blends was investigated, along with their water absorption and biodegradation. Increased ductile properties were achieved by adding pure and modified NR. Among the series of 90:10 TPS/modified NR blends by weight, the highest toughness (1,628 MJ/m3) was observed when the blend was formulated from ENR50 with 1.0 wt% of PEG. The water absorption of TPS/NR blends was lower than that of TPS but still exhibited a high-water absorption rate compared to the other conventional polymers. Biodegradation tests confirmed the biodegradation capability of TPS/NR blends, and more than 95% of the tested samples were biodegraded in soil within 120 days. These sustainable and eco-friendly TPS/NR blends could be potential materials for single or short-term use products, such as plant nursery pots and other disposable packaging. [ABSTRACT FROM AUTHOR]

The growing awareness of environmental concerns and the increasing demand for sustainable materials have driven the development of eco-friendly alternatives. Green composites have emerged as a widely adopted solution, owing to their biodegradability, eco-friendliness, and environmental benefits. Among green composites starch-based composites have made significant progress toward commercially viable products, but their weak mechanical characteristics, high hydrophilicity, and high density limit their widespread application. Researchers are exploring using agro-waste cellulosic fibers, abundant by-products from agricultural practices, as reinforcing fillers in the thermoplastic starch matrix. This critical review aims to highlights significant advancements made by incorporating agro-waste cellulosic fibers into various starch matrices. The findings reveal that the integration of these materials significantly enhances the mechanical properties, water resistance, and biodegradability of the resulting composites. This review also offers researchers and industry professionals valuable insights into sustainable materials. [ABSTRACT FROM AUTHOR]

• Starch- and petro-based bioplastics were anaerobically digested under H 2 /CO 2 or N 2. • Higher methane yield in H 2 /CO 2 than N 2 accomplishing successful biogas upgrading. • H 2 /CO 2 can enhance methane production with breakdown of starch-based bioplastic. To identify an economically viable waste management system for bioplastics, thermoplastic starch (TPS) and poly(butylene adipate-co-terephthalate) (PBAT) were anaerobically digested under hydrogen (H 2)/carbon dioxide (CO 2) and nitrogen (N 2) gas-purged conditions to compare methane (CH 4) production and biodegradation. Regardless of the type of bioplastics, CH 4 production was consistently higher with H 2 /CO 2 than with N 2. The highest amount of CH 4 was produced at 307.74 mL CH 4 /g volatile solids when TPS digested with H 2 /CO 2. A stepwise increased in CH 4 yield was observed, with a nominal initial increment followed by accelerated methanogenesis conversion as H 2 was depleted. This may be attributed to a substantial shift in the microbial structure from hydrogenotrophic methanogen (Methanobacteriales and Methanomicrobiales) to heterotrophs (Spirochaetia). In contrast, no significant change was observed with PBAT, regardless of the type of purged gas. TPS was broken down into numerous derivatives, including volatile fatty acids. TPS produced more byproducts with H 2 /CO 2 (i.e., 430) than with N 2 (i.e., 320). In contrast, differential scanning calorimetry analysis on PBAT revealed an increase in crystallinity from 10.20 % to 12.31 % and 11.36 % in the H 2 /CO 2 - and N 2 -purged conditions, respectively, after 65 days of testing. PBAT surface modifications were characterized via Fourier transform infrared spectroscopy and scanning electron microscopy. The results suggest that the addition of H 2 /CO 2 can enhance the CH 4 yield and increase the breakdown rate of TPS more than that of PBAT. This study provides novel insights into the CH 4 production potential of two bioplastics with different biodegradabilities in H 2 /CO 2 -mediated anaerobic digestion systems. [ABSTRACT FROM AUTHOR]

Thermoplastic starch (TPS) suffers from its intrinsic low mechanical strength and high brittleness due to its strong hydrogen bonding and low chain mobility. The conventional way to crosslink the TPS film can improve the strength and stiffness of the films, but usually reduces the flexibility of the film, and increases its brittleness. In this study, the incorporation of the hybrid nanofiller [1 wt% nanocellulose (C) and 4 wt% nano bentonite (B)] into the TPS proved to improve greatly the films' strength and flexibility. The hybrid nanofillers with ratio 4B:1C was incorporated into the crosslinked thermoplastic corn starch (CR-TPCS) film to increase the its flexibility and toughness and produced a high mechanical strength fully biodegradable film. Two different aqueous carboxylic acids: citric acid (CA) and tartaric acid (TA) with different pH values (2,4,6) as the green crosslinker were employed. Substantial increase of tensile strength (3.98 to 9.17 MPa), Young's modulus (9.10 to 46.30 MPa) and elongation at break (55.2 to 135.7%) was observed for the CA- 4B1C/pH2 films compared to the CR-TPCS films. The melting temperature (Tm) of the CA-4B1C/pH2 improved compared to the TPCS/4B1C (un-crosslinked) film due to its crosslinking effect. Meanwhile, the CA-4B1C films exhibited the highest degree of substitution and di-esterification with the lowest swelling and water solubility properties due to the formation of a special "bridge" structure between the CA, nanocellulose and plasticizer. The "bridge" structure developed between the TPCS chains serves as the toughener to motivate higher chain stress relaxation and load endurance. The crosslinked "bridge structure" also proved to effectively reduce the retrogradation phenomenal in the TPCS films. This combination method of hybridization and crosslinking is an efficient, low cost, and environmentally friendly technique to overcome the low flexibility and brittleness problem of the TPS based packaging film. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Cereals, Oils & Foods is the property of Science & Technology of Cereals, Oils & Foods Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pandanus amaryllifolius fibre (PAF) is an agricultural waste plant derived from the natural cellulosic source of fibre that can be used in various bio-material applications. In the present study, a novel biodegradable thermoplastic cassava starch/beeswax blends reinforced with Pandanus amaryllifolius fibre (TCPS/BW/PAF) bio-composites were successfully developed at varied Pandanus amaryllifolius fibre concentrations of 0, 10, 20, 30, 40, 50 and 60 wt% while beeswax loading was remained constant at 2.5 wt% concentration using hot moulding compression method. A comprehensive characterisation of TCPS/BW/PAF bio-composites was examined in terms of their physical, mechanical, thermal and biodegradation properties. The addition of Pandanus amaryllifolius fibre has significantly improved tensile strength and tensile modulus at maximum value obtained 10.9 and 606.5 MPa, respectively as well as flexural strength and flexural modulus of bio-composite at maximum value obtained 21.37 and 523.76 MPa, respectively until 50 wt% Pandanus amaryllifolius fibre loading. Surface morphology of the fractured tensile samples PAF10 to PAF50 shows compacted structure and fibre breakage, indicating effective stress transfer from starch matrix to PAF during tensile force application. Furthermore, the addition of Pandanus amaryllifolius fibre improved thermal stability from TG, DTG and DSC results; improved crystallinity from XRD analysis; reduced water and moisture affinity from physical properties testing, and lowered the biodegradation rate. Overall, this study shows the potential of TCPS/BW/PAF bio-composites in biopolymer application and bio-packaging industries. [ABSTRACT FROM AUTHOR]

The incorporation of different amounts of Gum Arabic (GA) in thermoplastic starch (TPS) obtained by extrusion and subsequent thermocompression has been studied. The sheets have been characterized by means of XRD, FTIR, TGA, moisture content, SEM, mechanical properties, antimicrobial activity and biodegradability via composting. The FTIR analysis of the sheets shows the presence of ester groups, while the TGA shows the presence of new processes and a residue much higher than expected is obtained. No changes in crystallinity are observed by XRD. The inclusion of GA confers antimicrobial properties to thermoplastic starch against the Gram + and Gram – bacteria studied even at the smaller concentrations. For a low GA content (0.5 and 1 g GA/100 g TPS) a homogeneous material is observed by SEM, as well as an important increase in tensile strength, modulus and deformation at break, which are very interesting properties facing the applicability of this material in single use plastics which are in contact with food or other consumable goods. At higher contents of GA, hollows and cracks appear in the material, compromising the mechanical properties. In all cases, the inclusion of GA delays the biodegradation process in soil, which can be related to its antibacterial capacity and especially in case of GA concentrations of 2 and 5 g/100 g of TPS with lower humidity of these TPS sheets.

This work aims to develop and characterize blends of thermoplastic starch (TPS) modified with citric acid and poly(butylene-adipate-co-terephthalate) (PBAT), using sweet potato (SP) and cassava (C) as starch sources. The blends were produced through extrusion, combining thermoplastic starch with PBAT, and characterized using Infrared Absorption Spectroscopy, X-ray diffraction, a scanning electron microscope, tensile testing, and swelling analyses. The starch granules from SP and C showed variations in structure and composition (specifically in the amylose-to-amylopectin ratio), influencing the morphology and properties of the blends. The TPS-SP/PBAT blends exhibited greater resistance and lower hydrophilicity compared to the TPS-C/PBAT blends. Variations in the properties of the blends were also observed with different amounts of the biodegradable polyester used. The developed blends offer a long-term sustainable alternative to conventional polymers in the manufacturing of disposable packaging for the food industry.

Waste tempura flakes collected from local restaurants were upcycled to be utilized as a polymer filler material. The oil fraction in collected waste tempura flakes were extracted two times via centrifugal solid-liquid separation and organic solvent extraction. Then, oil-extracted residual starch was freeze-milled to produce fine powders. Waste tempura flake-derived starch powder was substituted with 1%, 3%, and 5% (wt%) of virgin starch powder to produce thermoplastic starch. Composition, X-ray diffraction, and Fourier transform infrared analyses showed that the mixture was successfully thermally plasticized. Substitution of waste tempura flake-derived starch decreased tensile strength while increasing elongation at break of some samples. Produced thermoplastic starch samples again were compounded with polylactic acid (PLA) and poly-butylene adipate-co-terephthalate (PBAT) following a mixing ratio of 3:5:2. The analyses indicated that thermoplastic starch, PLA, and PBAT were successfully compounded. The compound containing 1 wt% substituted thermoplastic starch showed the minimal mechanical strength decrease. This study revealed the possibility of upcycling waste fried food into a valuable bioplastic material. Waste tempura flakes can be utilized as both bio-jet fuel and bioplastic filler material.

Global growing concern on plastics disposal and their environmental impact has impulsed the development of lower impact biodegradable plastics, however their functional properties and processability are still limited. In this study, thermoplastic starch (TPS) was synthetized through reactive extrusion (REX) to obtain single oxidized thermoplastic (O-TPS) and single maleated thermoplastic (MA-TPS), as well as, dual (oxidized-maleated thermoplastic (O-MA-TPS) modified starches aiming to incorporate new functionalities, diminish the viscosity and improve TPS processability. Spectroscopic analysis showed different band intensities as a result of TPS modification. TPS presented B-type and V-type crystal structures. O-MA-TPS showed the lowest percentage of crystallinity and complex viscosity values compared to single modified TPS because the combination of modifications. The specific mechanical energy decreased with respect to chemical modifications of starch (TPS > O-TPS > MA-TPS > O-MA-TPS), which were associated with the diminishing of viscosity resulting from the modification and starch-glycerol interactions. These starches can be incorporated into mixtures with other plastic polymers, by allowing better mixing (minor viscosity difference) and the replacement of a greater amount of plastic with TPS or in applications where a TPS with lower viscosity and easier processability is required. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate–co–terephthalate) (PBAT) is widely used for production of biodegradable films due to its high elongation, excellent flexibility, and good processability properties. An effective way to develop more accessible PBAT-based bioplastics for wide application in packaging is blending of PBAT with thermoplastic starch (TPS) since PBAT is costly with prices approximately double or even triple the prices of traditional plastics like polyethylene. This study is focused on investigating the influence of TPS/PBAT blend ratio and montmorillonite (MMT) content on the physical and mechanical properties and molecular mobility of TPS–MMT/PBAT nanocomposites. Obtained TPS–MMT/PBAT nanocomposites through the melt blending process were characterized using tensile testing, dynamic mechanical thermal analysis (DMTA), and X-ray diffraction (XRD), as well as solid-state 1H and 13C NMR spectroscopy. Mechanical properties demonstrated that the addition of TPS to PBAT leads to a substantial decrease in the tensile strength as well as in the elongation at break, while Young's modulus is rising substantially, while the effect of the MMT addition is almost negligible on the tensile stress of the blends. DMTA results confirmed the formation of TPS domains in the PBAT matrix. With increasing TPS content, mobility of starch-rich regions of TPS domains slightly increases. However, molecular mobility in glycerol-rich regions of TPS domains in the blends was slightly restricted. Moreover, the data obtained from 13C CP/MAS NMR spectra indicated that the presence of TPS in the sample decreases the mobility of the PBAT chains, mainly those located at the TPS/PBAT interfaces. [ABSTRACT FROM AUTHOR]

Starch is a natural polymer material composed of α-glucose molecules with a wide range of sources, and mainly in the roots and stems of plants. It is inexpensive, renewable and biodegradable. The preparation of natural degradable plastic films from starch is of great significance to solve the problem of environmental pollution. Compared with starch-based materials, synthetic thermoplastic polymers such as polyethylene, polypropylene and polystyrene have disadvantages such as irritating odor, non-biodegradable and polluting the environment. Biodegradable thermoplastic materials made from starch have become a hot research topic for researchers. In this paper the structure and properties of starch is described, together with the plasticization methods, the ways to improve the barrier and mechanical properties of thermoplastic starch. Also the research progress and the outlook of thermoplastic starch-based materials are summarize. [ABSTRACT FROM AUTHOR]

The rising concern of environmental issues from the non-degradable conventional polymers is triggering the development of sustainable and renewable polymers. Thermoplastic starch (TPS) has been known to have huge potential to substitute conventional synthetic polymers. A thermoplastic starch was prepared using a non-food bitter cassava starch with isosorbide as plasticizer. To improve the dispersion and interfacial affinity of thermoplastic starch and boost the compatibility between starch and isosorbide, citric acid (CA) was used as an additive. The influence of citric acid to the TPS was then investigated. The result shows that citric acid improved tensile strength from 8.68 MPa to 11.98 MPa. The addition of citric acid at a concentration of 1 – 10 wt % can increase glass transition temperature (Tg) from 48.81°C to 63.89°C and storage modulus at 25°C from 1.20 GPa to 3.47 GPa. Two degradation temperatures (Td) were detected which are Td1onset value was decrease from 83.32°C down to 79.78°C while Td2onset value was decrease from 275.29°C down to 247.17°C and Td2max from 311.12°C to 295.06°C. [ABSTRACT FROM AUTHOR]