There is currently a growing interest in biopolymers, such as bacterial cellulose and thermoplastic starch, which are renewable and abundantly available in nature. This study investigated the multilayer sandwich composite with thermoplastic starch and bacterial cellulose, using water (TPS/BC-w) and glycerol (TPS/BC-g) as coupling agents. The composites produced by compression molding resulted in a homogeneous, transparent and flexible structure. TPS/BC-w showed superior mechanical property and better adhesion compared to TPS/BC-g. Therefore, the permeability, biodegradation, hydrothermal aging and stability analyses were conducted only for TPS/ BC-w. The water vapor permeability of TPS/BC-w is 6.7 times lower than that of thermoplastic starch, indicating better barrier performance. Thermoplastic starch and bacterial cellulose degraded in about 9 days, and TPS/BCw degraded in 60 days. Biodegradation analysis by COQ release confirmed the complete biodegradation process, with COQ emissions of 57 %, 42.5 % and 39.6 % after 120 days for thermoplastic starch, bacterial cellulose and TPS/BC-w, respectively. TPS/BC-w remained intact for more than a year, in an environment without direct contact with soil or water. These results indicate that TPS/BC-w composed of natural macromolecules may exhibit functional properties and is useful for applications such as short-shelf-life packaging, particularly for dry products, due to its barrier properties and controlled biodegradability.

BackgroundUrea-based fertilizers are essential for agricultural productivity but contribute to environmental degradation by releasing soil nitrogen (N) through N leaching and runoff. To address these issues, this study develops and characterizes slow-release composites of thermoplastic starch (TPS) and epoxidized natural rubber (ENR) that incorporate 46-0-0 fertilizer. TPS, recognized for its moisture sensitivity and biodegradability, was blended with ENR to enhance matrix compatibility and optimize nutrient release from the fertilizer. The blending process included different fertilizer concentrations (6.9, 10, 15, and 20 wt%) within various components of the composite.ResultsThe characterization included evaluation of mechanical properties, water absorbance, biodegradability in soil, ammonium release, and ammonium leaching. The TPS/ENR composites exhibited a two-stage decomposition, with TPS dissolving first to provide an initial nutrient boost, followed by the biodegradation of ENR to ensure sustained nutrient delivery. Ammonium release assays demonstrated that TPS/ENR composites delayed nutrient dissolution compared to conventional fertilizers, significantly reducing nitrogen loss through leaching. Notably, the TPS/ENR composite with 6.9 wt% of 46-0-0 fertilizer exhibited the highest efficiency, achieving sustained ammonium release and enhancing soil nitrogen retention while mitigating phytotoxicity in lettuce and maize germination assays.ConclusionsThese findings highlight the potential and environmental benefits of delivering fertilizer in TPS/ENR composites to improve nitrogen fertilizer efficiency in agricultural systems. The slow-release mechanism provides both initial and sustained nutrient supply, addressing the dual challenges of early crop nutritional needs and long-term environmental sustainability.

This study investigates the incorporation of thermoplastic starch (TPS) into polybutylene adipate terephthalate (PBAT) to create biodegradable plastic wraps for pathological waste burial in soil. TPS is added to PBAT to enhance biodegradability, as PBAT alone degrades slowly. The research examines the mechanical properties, biodegradation, morphology, and swelling behaviour of the blends. Key tests include xenon arc light exposure for accelerated aging, a formalin swelling test for permeability, and soil degradation analysis for weight loss. Results show that adding TPS significantly reduces tensile strength (65.53%) and elongation at break (93.35%), but the material still effectively serves its purpose as a wrapping for pathological waste. Morphological analysis reveals phase separation, and UV exposure further decreases tensile strength by 27.6%. The highest TPS composition (30TPS/70PBAT) shows the fastest mechanical degradation, indicating accelerated biodegradation. Despite minimal formalin absorption (16% within 1 day), the blends prevent formalin leaching, making them suitable for pathological waste containment.

Developing bio-blends and biocomposites has become a widespread strategy to combat plastic pollution in line with sustainability principles and decarbonization necessities. Although chemically modified ternary and quaternary biocomposites are developing rapidly because of their broader processing and performance windows than single matrix and binary counterparts, a few have been reported about their biodegradation. Herein, diisocyanates-based chemically modified ternary biocomposites based on poly(butylene adipate-co-tere- phthalate), thermoplastic starch (TPS), poly(epsilon-caprolactone) (PCL), and cellulose (Mater-Bi/PCL/cellulose) are prepared and undergone soil burial biodegradation providing a broader perspective on biodegradation of complicated systems. The mass gain of sunflower sprouts, weight retention, and the appearance of biocomposites are studied and discussed in the course of biodegradation. The unfilled Mater-Bi/PCL bio-blends presented moderate mass loss over 12 weeks, attributed to the presence of TPS in the Mater-Bi phase. The PCL addition hindered TPS decomposition and featured a noticeably lower degradation rate compared to previous reports. A significant increase in the b* parameter (position on the blue-yellow axis in the CIELAB color space), along with the yellowness and whiteness indices, was observed. Prior to soil burial, roughness differences were negligible. Still, they significantly increased over time due to the higher hydrophilicity of unfilled Mater-Bi/PCL and biocomposite containing unmodified filler.

The PBAT (poly (butylene adipate- co-terephthalate) is a promising biodegradable material. However, it is often blend with hydrophilic polymers since its degradation rate in the aquatic environment is still limited. In this study, the blend PBAT/TPS (thermoplastic starch) films, namely BFs, were prepared by a blow extrusion approach, and evaluated for hydrolysis in four studied mediums acid (HCl, 1 M, 2 M, and 3 M), alkaline (NaOH, pH = 9, 11, and 13), phosphate buffer (pH = 7.4), and artificial seawater. The hydrolyzed BFs were characterized by weight loss, mechanical properties, scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), and differential scanning calorimetry (DSC). A larger starch content in the BFs caused hydrolysis more quickly. The highest hydrolytic rate was found in the alkaline solution, followed by the acid medium. The complete abiotic hydrolysis of the BFs was 3 M HCl for 14 days or NaOH (pH 13) for 35 days. After 180 days of incubation, the film containing 70.5 % PBAT/TPS granules has been associated with the highest biodegradation rate of 76.31 % in composting.

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 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.

This research aims to develop an environment-friendly composite material that possesses enhanced fire retardant (FR), thermal, as well as mechanical characteristics. The aim has been accomplished with the development of a jute/thermoplastic starch (TPS) based bio-composite. The fire retardancy and thermal stability of the jute/TPS composite were enhanced by the incorporation of magnesium carbonate hydroxide pentahydrate (MCHPH). Upon exposure to heat or fire, the MCHPH particles decompose in a two-stage process to yield water vapors and a char layer of MgO and CO2, which restrict access to oxygen and result in flame suppression. Moreover, the main contribution of the article is the improvement of mechanical properties simultaneously with the enhancement in the fire retardant and thermal properties, which have rarely been reported in the literature. The enhancement of mechanical properties is supported by the compatibility of MCHPH particles with jute/TPS. All the composites were developed with a constant 40 % jute fiber content, while the MCHPH concentration varied from 0 % to 9 % by weight. The tensile strength of TPS was enhanced by 595 % with the reinforcement of jute fiber and MCHPH nano-filler. Compatibility between TPS, jute, and MCHPH was discovered through Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) was used to study the fractured surfaces of the composites. Thermo-gravimetric analysis (TGA) revealed a decrease in the weight loss of the MCHPH-filled jute/ TPS composites at high temperatures. The vertical burning test also revealed that the composites met the re-quirements for a V-0 rating. The heat release rate of the composites was reduced by 36 % after the addition of MCHPH, as measured by cone calorimetry test. The biodegradability test confirmed the eco-friendly nature of the composites by demonstrating significant weight loss in soil over a 4-weeks period. Thus, the present study provided the basis for the development of a novel green composite with commendable gains in flame resistance, thermal stability, and mechanical robustness.

In this study, the influence of the incorporation of eucalyptus (EO), tea tree (TT) and rosemary (RO) essential oils and Chiriyuyo extract (CE) on the structure and properties of thermoplastic starch (TPS) obtained from potato starch, glycerin and water was evaluated. All oils and the extract were used at a concentration of 0.5 g/100 g of TPS, while for TT, the effect of the concentration was also studied. The mixtures obtained were processed by extrusion and thermocompression molding. The sheets were characterized by XRD, FTIR, TGA, SEM and analyses of their mechanical properties, antimicrobial characteristics and biodegradability. The results show that the use of small concentrations of the oils in 70TPS does not induce changes in the TPS structure according to the results of XRD, FTIR and TGA, with each essential oil and CE affecting the mechanical properties unevenly, although in all cases, antimicrobial activity was obtained, and the biodegradability of TPS in soil was not modified. An increase in the concentration of TT in 60TPS causes marked changes in the crystallinity of TPS, providing a greater modulus with a higher concentration of TT. Regardless of the amount of TT, all sheets maintain antimicrobial characteristics, and their biodegradation in soil is delayed with a higher oil content.