Poly Butylene Adipate Co-terephthalate Research Articles

Continuous co-digestion of sewage sludge and highly concentrated waste bioplastic hydrolyzate without shortening hydraulic retention time

Bioplastics have garnered substantial interest as alternatives to conventional petroleum-based plastics. However, their management and conversion to biogas continues to be significantly challenging. In this study, we evaluated the suitability of various plastics for hydrolysis at 160 °C for 12 h using different solvents. The biogas yield (BGY) of the monomers constituting these plastics and the obtained plastic hydrolyzates was comprehensively evaluated. When water was used as a solvent, 100 % hydrolysis of polylactic acid (PLA) and polybutylene succinate (PBS) was observed. When polybutylene adipate co-terephthalate (PBAT) and polyhydroxybutyrate (PHB) were hydrolyzed with water, the degradation ratio was approximately 30 %; however, using an aqueous lactic acid solution as a solvent improved the degradation ratio to 78 % and 100 %, respectively. In the BGY test of the plastic hydrolyzates, the biogas volumes derived from the hydrolyzates were 563, 461, 337, and 573 mL/g COD-added for PLA, PBS, PBAT, and PHB, respectively. With 1,160 gCOD/L waste PLA hydrolyzate, continuous co-digestion of sewage sludge and the hydrolyzate was conducted. Organic loading rates of sewage sludge and the hydrolyzate were 2.3 and 2.4 gCOD/L/d, respectively. The operation was stable and the methane production volume from the PLA hydrolyzate was 414 L/kgCOD-added. Using highly concentrated PLA hydrolyzate, the hydraulic retention time was 19.3 days, which was only 0.7 days shorter than that of anaerobic digestion of sewage sludge only (20 days). Therefore, highly concentrated PLA hydrolyzate maintains the retention time of normal sewage sludge digestion. Conclusively, the present study has crucial practical implications for plastic waste management.

Bioactive materials‐coated polybutylene‐adipate‐co‐terephthalate 3D‐printed scaffolds for application in the bone tissues engineering

AbstractBone tissue engineering (BTE) is a biomedical area that develops scaffolds capable of mimicking and repairing damage on bone tissue. For this, a popular and nonexpensive 3D printing technique named fused deposition modeling (FDM) has been used. The potential use of 3D scaffolds of poly(butylene adipate‐co‐terephthalate (PBAT) has been investigated in BTE since this polymer presents good biocompatibility and degradability, as well as mechanical properties like those offered by the natural bone. A single material does not have the features to promote cell adhesion, proliferation, and differentiation; the incorporation of bioactive substances can overcome this issue. This work aimed to develop 3D printed PBAT scaffolds by FDM technique and coated them with hydroxyapatite (H), bioglass (B), and gelatin (G) by solution immersion technique to obtain a functional biomaterial to be applied on the BTE. Structural characteristics and morphological and mechanical properties of the 3D scaffolds were evaluated. The cell proliferation and mineralization of pre‐osteoblastic cells (MC3T3‐E1) were accessed by methylthiazolyldiphenyl‐tetrazolium bromide, sulphorodhamine B, and Alizarin red assay, respectively. 3D printed PBAT scaffolds were successfully obtained by FDM, and the surface modification of 3D PBAT was proven through the changes observed in structural and morphological characteristics. In addition, the mechanical properties were improved in the modified scaffolds. Also, the coated 3D PBAT scaffolds with any bioactive substance increased and promoted cell proliferation and pre‐osteoblastic differentiation. Therefore, the combination of 3D PBAT scaffolds and H, G, and/or B (doped with niobium) is an alternative to produce functional biomaterials for BTE.

Evaluating novel biodegradable polymer matrix fertilizers for nitrogen-efficient agriculture.

Enhanced efficiency fertilizers (EEFs) can reduce nitrogen (N) losses in temperate agriculture but are less effective in the tropics. We aimed to design a new EEF and evaluate their performance in simple-to-complex tests with tropical soils and crops. We melt-extruded urea at different loadings into biodegradable polymer matrix composites using biodegradable polyhydroxyalkanoate (PHA) or polybutylene adipate-co-terephthalate (PBAT) polymers with urea distributed throughout the pellet. These contrast with commercially coated EEF that have a polymer-coated urea core. We hypothesized that matrix fertilizers would have an intermediate N release rate compared to fast release from urea or slow release from coated EEF. Nitrogen release rates in water and sand-soil columns confirmed that the matrix fertilizer formulations had a more progressive N release than a coated EEF. A more complex picture emerged from testing sorghum [Sorghum bicolor (L.) Moench] grown to maturity in large soil pots, as the different formulations resulted in minor differences in plant N accumulation and grain production. This confirms the need to consider soil interactions, microbial processes, crop physiology, and phenology for evaluating fertilizer performance. Promisingly, crop δ15N signatures emerged as an integrated measure of efficacy, tracking likely N conversions and losses. The three complementary evaluations combine the advantages of standardized high-throughput screening and more resource-intensive and realistic testing in a plant-soil system. We conclude that melt-blended biodegradable polymer matrix fertilizers show promise as EEF because they can be designed toward more abiotically or more microbially driven N release by selecting biopolymer type and N loading rate.

The impact of arbuscular mycorrhizal fungi and endophytic bacteria on peanuts under the combined pollution of cadmium and microplastics

It remains unclear how symbiotic microbes impact the growth of peanuts when they are exposed to the pollutants cadmium (Cd) and microplastics (MPs) simultaneously. This study aimed to investigate the effects of endophytic bacteria Bacillus velezens SC60 and arbuscular mycorrhizal fungus Rhizophagus irregularis on peanut growth and rhizosphere microbial communities in the presence of Cd at 40 (Cd40) or 80 (Cd80) mg kg−1 combined without MP or the presence of low-density polyethylene (LDPE) and poly butyleneadipate-co-terephthalate (PBAT). This study assessed soil indicators, plant parameters, and Cd accumulation indicators. Results showed that the application of R. irregularis and B. velezens significantly enhanced soil organic carbon and increased Cd content under the conditions of Cd80 and MPs co-pollution. R. irregularis and B. velezens treatment increased peanut absorption and the enrichment coefficient for Cd, with predominate concentrations localized in the peanut roots, especially under combined pollution by Cd and MPs. Under treatments with Cd40 and Cd80 combined with PBAT pollution, soil microbes Proteobacteria exhibited a higher relative abundance, while Actinobacteria showed a higher relative abundance under treatments with Cd40 and Cd80 combined with LDPE pollution. In conclusion, under the combined pollution conditions of MPs and Cd, the co-treatment of R. irregularis and B. velezens effectively immobilized Cd in peanut roots, impeding its translocation to the shoot.

Testing the Biodegradability and Biodegradation Rate of Bio-based Film Products in Composting Environment

Bio-based film products have a considerable interest as a replacement for petroleum synthetic polymers of plastics. They are manufactured with a blend of corn starch such as Poly Lactic Acid (PLA) and Poly Butylene Adipate-co-Terephthalate (PBAT) based raw materials that have been specifically engineered to facilitate the process of biodegradation and compost ability. Hence, biodegradable polymers have been regarded as a promising solution to tackle the pollution caused by the wide use of conventional polymers. As the main responsible institute for integrating environmental considerations into the country‘s development process, the Central Environment Authority of Sri Lanka has taken an action to ban food wrappers (lunch sheets) made from conventional polymers in Sri Lanka. Thus, this study was to determine the biodegradability of bioplastic materials lunch sheets, available on the Sri Lankan market that are labeled as 100% biodegradable but not certified as compostable. The other specific objectives are to identify the biodegradability rate of each brand of lunch sheets, categorize those lunch sheets according to their biodegradability and finally get an idea to determine the optimum conditions for the biodegradation of a bio- based lunch sheet. In this study, the test was carried out in a controlled composting environment located in Gampaha–Dompe Green Park. Three different brands of biodegradable bio-based film products were tested together with cellulose paper as the positive control and nonbiodegradable lunch sheet (LDPE) as the negative control. The project length was 15 weeks. Samples were placed into frames which are made of wooden slats as width=280 mm, length=340 mm and height=50 mm and a 1x1 mm polyethylene mesh was fixed onto the frames. The methodology adopted was based on the study conducted in the Czech Republic in 2016. The emphasis was put on discovering whether bio-based film products are biodegradable or not. The biodegradability of each bio-based film product was tested using Visual inspection; the decomposed samples were inspected visually comparing with initial samples, Weight loss measurement; the initial weight and the weight after decomposition were measured using an analytical balance, FTIR and TGA analysis. Furthermore, the quality of the compost was analyzed using quality parameters such as pH, electrical conductivity, moisture, organic carbon%, nitrogen%, phosphorous%, potassium%, C/N ratio and S. The visual inspection of Sample C revealed large cracks and porous structure than Sample A and Sample B. Positive control was completely digested and the negative control stayed as it is. According to the weight loss measurement analysis, the positive control totally degraded and degradation order was Sample C>Sample A>Sample B. The TGA only suggested a partial degradation of samples. FTIR analysis indicated that the positive control was totally biodegradable, Sample B and sample C partially biodegradable and Sample A and negative control were not biodegradable. Based on the results it can be concluded that bio- based film products have not decomposed completely but their color, texture changed. Sample B exhibited the highest degradation rate and exhibited a high degree ofdecomposition. The degradation rate can be summarized as Positive control>Sample B>Sample C>Sample A> Negative Control respectively. The main conclusion from this study is that the biodegradation of bioplastics materials strongly depends on both the environment in which they are placed and the chemical nature of the material. 
 Keywords: Biodegradation, Biobased film products, Composting environment

Effect of Starch Plasticization on Morphological, Mechanical, Crystalline, Thermal, and Optical Behavior of Poly(butylene adipate-co-terephthalate)/Thermoplastic Starch Composite Films.

Starches plasticized with glycerol/citric acid/stearic acid and tributyl 2-acetylcitrate (ATBC), respectively, were processed with poly (butylene adipate-Co-terephthalate (PBAT) via extrusion and a film-blown process. All the composite films were determined for morphology, mechanical, thermal stability, crystalline, and optical properties. Results show that the most improved morphology was in the 30% glycerol plasticized PBAT/thermoplastic starch (TPS) composite films, characterized by the smallest and narrowest distribution of TPS particle sizes and a more uniform dispersion of TPS particles. However, the water absorption of PBAT/TPS composite films plasticized with glycerol surpassed that observed with ATBC as a plasticizer. Mechanical properties indicated insufficient plasticization of the starch crystal structure when using 10% ATBC, 20% ATBC, and 20% glycerol as plasticizers, leading to poor compatibility between PBAT and TPS. This resulted in stress concentration points under external forces, adversely affecting the mechanical properties of the composites. All PBAT/TPS composite films exhibited a negative impact on the initial thermal decomposition temperature compared to PBAT. Additionally, the haze value of PBAT/TPS composite films exceeded 96%, while pure PBAT had a haze value of 47.42%. Films plasticized with 10% ATBC, 20% ATBC, and 20% glycerol displayed lower transmittance values in the visible light region. The increased transmittance of films plasticized with 30% glycerol further demonstrated their superior plasticizing effect compared to other PBAT/TPS composite films. This study provides a simple and feasible method for preparing low-cost PBAT composites, and their extensions are expected to further replace general-purpose plastics in daily applications.

Direct Pellet Three-Dimensional Printing of Polybutylene Adipate-co-Terephthalate for a Greener Future.

The widespread use of conventional plastics in various industries has resulted in increased oil consumption and environmental pollution. To address these issues, a combination of plastic recycling and the use of biodegradable plastics is essential. Among biodegradable polymers, poly butylene adipate-co-terephthalate (PBAT) has attracted significant attention due to its favorable mechanical properties and biodegradability. In this study, we investigated the potential of using PBAT for direct pellet printing, eliminating the need for filament conversion. To determine the optimal printing temperature, three sets of tensile specimens were 3D-printed at varying nozzle temperatures, and their mechanical properties and microstructure were analyzed. Additionally, dynamic mechanical thermal analysis (DMTA) was conducted to evaluate the thermal behavior of the printed PBAT. Furthermore, we designed and printed two structures with different infill percentages (40% and 60%) to assess their compressive strength and energy absorption properties. DMTA revealed that PBAT's glass-rubber transition temperature is approximately -25 °C. Our findings demonstrate that increasing the nozzle temperature enhances the mechanical properties of PBAT. Notably, the highest nozzle temperature of 200 °C yielded remarkable results, with an elongation of 1379% and a tensile strength of 7.5 MPa. Moreover, specimens with a 60% infill density exhibited superior compressive strength (1338 KPa) and energy absorption compared with those with 40% infill density (1306 KPa). The SEM images showed that with an increase in the nozzle temperature, the quality of the print was greatly improved, and it was difficult to find microholes or even a layered structure for the sample printed at 200 °C.

The Effect of Electrospinning Parameters on the Electrospun Polybutylene Adipate Co-Terephthalate (PBAT) Biodegradable Scaffold

Electrospinning is a cost-effective and versatile technique to fabricate continuous fibers ranging from submicron diameter to nanometer diameter. Polybutylene adipate-co-terephthalate (PBAT) has been investigated as a fibrous scaffold because of its low crystallinity, rapid biodegradability, and excellent mechanical properties, particularly for its high toughness and flexibility. However, the potential of the PBAT fibrous scaffold for medical purposes is still limited. PBAT blends with biocompatible polymers have been developed and investigated for tissue engineering applications. Herein, the preliminary research examines the processability of neat PBAT as a fibrous scaffold by varying several electrospinning processing parameters, such as solution concentration, voltage, flow rate, and tip to collector distance. The aim is to obtain continuous, smooth, and bead-free fibers. The electrospun fibers were examined using a scanning electron microscope (SEM) to determine its diameters. The optimum parameters for obtaining a continuous, bead-free PBAT fibrous scaffold were 20% w/v concentration, 19 kV voltage, 2 mL/h flow rate, and a 15 cm distance.

Upcycling waste tempura flake-derived starch powder as an environment-friendly polymer matrix filler for thermoplastic starch compounds

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.

Synthesis of ionic liquid modified 1‐D nanomaterial and its strategical distribution into the biodegradable binary polymer matrix to get reduced electrical percolation threshold and electromagnetic interference shielding effectiveness

AbstractIonic liquid is increasingly being used as a chemical modulator of multi‐walled carbon nanotubes (MWCNT). Here, we report the practical method for producing biodegradable electromagnetic interference (EMI) shield films made of thermoplastic polyurethane (TPU), polybutylene adipate‐co‐terephthalate (PBAT), and 1‐(2‐aminoethyl)‐3‐methyl‐1H‐imidazol‐3‐ium modified MWCNT (MIL). The field emission scanning electron microscopy study of cryo‐fractured 50:50 PBAT/TPU blend giving co‐continuous morphology and subsequent polymer EMI shield nanocomposite material had shown the co‐continuous nanofiller distribution. The nanoparticles were chosen to be distributed in the PBAT portion, according to subsequent research employing HRTEM and DMA. The electrical percolation threshold (EPT) is determined to be situated within 1–3 wt% of nanoparticles loading as the remarkable shift in total EMI shielding efficiency from −14.6 dB (for 1 wt%) to −28.6 dB (for 3 wt%) of nanoparticle‐loaded film at 10 GHz (in X‐band region) for a 0.8 mm thick film reveals that the EPT is approximately at 2 wt% of nanoparticle loading. The effective EMI shielding of −37.3 dB was achieved by 10 wt% of MIL loading.

Biochar from Digestate Pyrolysis as a Filler for Biopolymer Blends: Effect of Blend Composition

Abstract This study investigates the effect of biochar (BC) as a filler for biopolymer blends, with a focus on the effect of the biopolymer weight ratio on the final BC-added blends. The blends studied in this work were obtained by varying the weight ratio of poly-butylene adipate-co-terephthalate (PBAT) and polylactic acid (PLA) due to their great importance in packaging and agricultural fields. BC has been produced in our laboratories by the slow pyrolysis of the digestate obtained from the anaerobic digestion of the organic fraction of municipal solid waste (OFMSW). After pyrolysis, digestate-derived biochar has been milled and sieved to produce a powdery form with diameter of less than 45 μm. In order to better investigate the filler/polymer interactions, biochar particles were dimensionally, morphologically and chemically characterised. The inhomogeneity of the feedstock is responsible for content and high diversity of inorganics in biochar surface. The effect of BC on PBAT and PLA biopolymer matrices is different, and for the blend compositions the relative weight ratio between PBAT and PLA plays an important role. Furthermore, the biocomposite blend has been fully characterised: rheological, morphological, mechanical and dynamic-mechanical characterisations have been carried out, highlighting how the properties results strongly influenced by the presence of BC in the blend. In addition, a study of the viscous molar mass of the two polymer matrices when processed in the presence or absence of BC particless highlighting that a strong chemical interaction occurs between PLA and BC particles, unlike PBAT and BC. Graphical Abstract

Scale-up fabrication of a biodegradable PBAT/PLA composite film compatibilized with a chain extender for industrial agricultural mulch film application

Low-density polyethylene (LDPE) mulch films have become a prevalent practice in agriculture to increase crop yield. However, because of their high environmental impact after use, biodegradable plastic films are considered desirable alternatives in agroecosystems. Herein, a polybutylene adipate-co-terephthalate (PBAT) and polylactic acid (PLA) composite film compatibilized with a chain extender (CE) was prepared via a two-step extrusion process. First, PBAT and PLA were blended at different ratios in a laboratory-scale twin-screw extruder, and the PBAT/PLA blends (80/20 wt.%) compatibilized with 1 phr of CE exhibited the most comparable physicochemical properties. The CE integration into the PBAT/PLA binary blend significantly increased mechanical rigidity and strength (p ≤ 0.05). The enhanced compatibility between the immiscible polymers was verified through thermal and phase morphological analyses. The optimum composite was then produced using a pilot-scale extrusion system. The pilot-scale extruded optimal biodegradable mulch composite exhibited excellent water barrier properties, as evidenced by a water vapor permeability of 0.83 g mm/m2·day·kPa and a water contact angle of 93.77° These values surpassed those of commercially available biodegradable mulch films. Furthermore, it demonstrated a weight reduction of 2.9% during a 3-month period of soil burial, exhibiting durability compared to commercial biodegradable mulch films. These results suggest that the developed film has great potential for practical food and agricultural applications.

Enhancing biodegradation of PBAT through bio-stimulation using Pseudozyma jejuensis for effective plastic waste reduction

Polybutylene adipate-co-terephthalate (PBAT) is a flexible and biodegradable material that finds applications in mulching film and the food packaging industry. In this study, we aimed to address the global plastic waste problem by developing an improved biodegradation system for PBAT. Our focus was on utilizing the biodegradation capabilities of Pseudozyma jejuensis, a microorganism known for its ability to decompose Polycaprolactam (PCL). Through bio-stimulation, we aimed to enhance the growth mechanism of P. jejuensis and optimize PBAT biodegradation. Our results demonstrated significant structural changes in the PBAT film, as revealed by FT-IR analysis. Moreover, FE-SEM imaging exhibited evident surface erosion and pitting, indicating physical alterations due to biodegradation. These findings provide strong evidence for the efficiency of our developed biodegradation system. To fully harness the potential of this system and enable its practical implementation, further research is warranted to optimize and scale up the process. Our work contributes to the ongoing efforts to combat the global plastic waste crisis, offering a valuable solution for the efficient biodegradation of PBAT.

Effect of Plasticizer and Compatibilizer on Properties of Polybutylene Adipate-Co-Terephthalate (PBAT) with Acetylated Starch

Effect of Plasticizer and Compatibilizer on Properties of Polybutylene Adipate-Co-Terephthalate (PBAT) with Acetylated Starch

Assessing labelled carbon assimilation from poly butylene adipate-co-terephthalate (PBAT) monomers during thermophilic anaerobic digestion

PBAT (poly butylene adipate-co-terephthalate) is a widely used biodegradable plastic, but the knowledge about its metabolization in anaerobic environments is very limited. In this study, the anaerobic digester sludge from a municipal wastewater treatment plant was used as inoculum to investigate the biodegradability of PBAT monomers in thermophilic conditions. The research employs a combination of 13C-labelled monomers and proteogenomics to track the labelled carbon and identify the microorganisms involved. A total of 122 labelled peptides of interest were identified for adipic acid (AA) and 1,4-butanedio (BD). Through the time-dependent isotopic enrichment and isotopic profile distributions, Bacteroides, Ichthyobacterium, and Methanosarcina were proven to be directly involved in the metabolization of at least one monomer. This study provides a first insight into the identity and genomic potential of microorganisms responsible for biodegradability of PBAT monomers during anaerobic digestion under thermophilic conditions.

Dynamics of macroplastics and microplastics formed by biodegradable mulch film in an agricultural field

Conventional plastic mulch brings agronomic and economic benefits to crop production, but a large amount of plastic waste amasses when the mulch is removed from the fields after harvest. Soil-biodegradable plastic mulch (BDM) has emerged as a promising alternative to conventional plastic mulch as it can be tilled into the soil after harvest, thereby alleviating disposal problems. However, direct evidence on complete degradation of biodegradable mulch under natural conditions is still lacking. We quantified the dynamics of macro- (>5 mm) and microplastics (0.1–5 mm in size) in four years after a one-time application of mulch in a field with monoculture maize. The BDM feedstock was polybutyleneadipate-co-terephthalate (PBAT) and polylactic acid (PLA)-based, and both a clear and black BDM were tested. The BDM plastic mulch films degraded into macro- and micoplastics. Macroplastics disappeared 2.5 years after mulch incorporation. We developed a new extraction method for biodegradable microplastics using a sequential density fractionation approach with a H2O and a ZnCl2 solution. Microplastic concentrations in the soil ranged from 350 to 525 particles/kg after 2.5 years, 175 to 250 particles/kg after 3 years, and 50 to 125 particles/kg after 3.5 year following mulch incorporation. This continuous decrease of detectable plastic particle concentrations in soil suggests that BDMs fragment degrade into smaller and smaller particles, which eventually may biodegrade completely. While we cannot ascertain whether persistent and undetectable nanoplastics may form, macro- and microplastics formed from BDM seem to disappear with time.

Preparation of ultrafine wheat straws with co-milling and its incorporation for biodegradable mulch film production with enhanced performance

Although polybutylene adipate-co-terephthalate (PBAT)-based biodegradable mulch films are potential in replacing the traditional polyethene ones with increased cultivation sustainability, some practical issues including the high price and low performance still need to be resolved. Here, ultrafine powder of zero-cost straws was doped into PBAT-based films due to its toughness and ultraviolet (UV)-resistance. The powder was prepared by co-milling with a few calcium carbonates, which act as not only a friction agent to greatly increase the milling efficiency, but also an anti-blocking agent during film blowing. Slight changes in rheological and thermal behaviors of the composite films were observed with the introduction of this ultrafine filler, thus have no crucial effect on film processing. However, the UV-blocking and aging-resistant properties of the films were both enhanced, which is quite essential to a mulch film for long-term cultivation. Meanwhile, the mechanical and the water vapor barrier properties were also slightly increased with the addition of < 10 wt% fillers. It is noted that the films can meet the standards of biodegradable mulch films even after 80.9-h UV irradiation. Besides, the cost is estimated to reduce over 8.14%, which makes it quite feasible for mulching in the future.

Biodegradable Electrohydraulic Soft Actuators

Biodegradable materials decompose and return to nature. This functionality can be applied to derive robotic systems that are environmentally friendly. This study presents a fully biodegradable soft actuator, which is one of the key elements in “green” soft robotics. The working of the actuator is based on an electrohydraulic principle, which is similar to that of hydraulically amplified self‐healing electrostatic actuators. The actuator developed in this study consists of a dielectric film made of polylactic acid (PLA) and polybutylene adipate‐co‐terephthalate (PBAT), with soybean oil as the dielectric liquid and electrodes made from a mixture of gelatin, glycerol, and sodium chloride (NaCl). The synthesized biodegradable electrode material exhibits a Young's modulus of 0.06 MPa and resistivity of 258 Ω·m when the mass fraction of NaCl relative to the amount of gelatin and glycerol is 10 wt%. The softness and resistivity of the electrode material results in actuation strain values of 3.2% (at 1 kV, corresponding to 1.2 kV mm−1) and 18.6% (at 10 kV, corresponding to 9.6 kV mm−1) for the linear‐type and circular‐type actuators, respectively. These values obtained for the biodegradable electrohydraulic soft actuators are comparable to those of nonbiodegradable actuators of the same type, representing the successful implementation of the concept.

Tannic acid as a crosslinking agent in poly(butylene adipate-co-terephthalate) composite films enhanced with carbon nanoparticles: Processing, characterization, and antimicrobial activities for food packaging

The disposal of plastics waste is currently a major environmental problem. Plastics are used frequently and in more variety in everyday life, which has an effect on the environment. As a result of the emissions of carbon dioxide caused by burning of non-biodegradable polymers like polyethylene, polypropylene, and polyvinyl chloride, there is a growing concern of a global warming. This article discusses the carbonization and activation of KOH to produce porous carbon nanoparticles (CNPs). The solution casting method was used to produced composites of poly(butylene adipate-co-terephthalate (PBAT) with CNPs and tannic acid (TA). PBAT composites employing CNPs as reinforcement and TA as a cross-linker. TA and CNPs have been taken into account in investigating the morphological and antimicrobial activities of PBAT-based composites. The mechanical strength of PBAT/TA/CNPs composites increased as a result to the strengthening characteristics of CNPs. The thermal characterization of PBAT/TA/CNPs composites was improved with TA and CNPs, based on thermogravimetric analysis (TGA). Contact angle measurements show that after reinforcement, PBAT/TA/CNPs composites became hydrophobic. In PBAT/TA/CNPs composites, the oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) are reduced. The PBAT/TA/CNPs composites showed greater antimicrobial activity against the food-borne pathogenic microorganisms E. coli and S. aureus. Also, the results of food quality tests that PBAT/TA/CNPs composites used to have an improved shelf life for sliced carrot than control, commercial and PBAT film extending it from 1 to 12 days. The results indicated that PBAT/TA/CNPs composites would be suitable choices for materials to be used in food packaging.

Aging of biodegradable-mulch-derived microplastics reduces their sorption capacity of atrazine

Degradable plastics are gradually regarded as alternatives of conventional, synthetic organic polymers to reduce the plastics or microplastics (MPs) pollution; however, the reports upon environmental risk of degradable plastics are still limited. In order to evaluate the potential vector effect of biodegradable MPs on coexisting contaminants, sorption of atrazine onto pristine and ultraviolet-aged (UV) polybutylene adipate co-terephthalate (PBAT) MPs and polybutylene succinate co-terephthalate (PBST) MPs were investigated. The results showed that, UV aging led to more wrinkles and cracks on the surface, increased homogeneous chains proportion, enhanced hydrophobicity, and enlarged crystallinity of both MPs. The sorption kinetics of atrazine to MPs fitted well into pseudo-first-order (R2 = 0.809–0.996) and pseudo-second-order (R2 = 0.889–0.994) models. In the concentration range of 0.5–25 mg L−1, the sorption isotherm fitted into linear (R2 = 0.967–0.996) and Freundlich model (R2 = 0.972–0.997), indicating that the absorption partitioning was the dominant sorption mechanism. The partition coefficient (Kd) of atrazine to PBAT- MPs (40.11–66.01 L kg−1) was higher than that of PBST- MPs (34.34–57.96 L kg−1), and the Kd values of both MPs declined for aged MPs. The specific surface area, hydrophobicity, polarity and crystallinity of MPs jointly interpreted the changing sorption capacity of the MPs. In the present study, both aged PBAT- and aged PBST- MPs exhibited lower vector potential to atrazine than pristine MPs, suggesting reduced risk of being a pollutant carrier, which is of great significance for the development of biodegradable plastics.