Polybutylene Adipate Terephthalate Research Articles

Comparison of the Effects of LDPE and PBAT Film Residues on Soil Microbial Ecology.

The plastic film is extensively applied with limited recycling, leading to the long-run residue accumulation in soil, which offers a distinctive habitat for microorganisms, and creates a plastisphere. In this study, traditional low-density polyethylene (LDPE) plastic film and biodegradable polybutylene adipate terephthalate (PBAT) plastic film materials were selected to test their effects on soil microbial ecology. Based on high-throughput sequencing, compared to the soil environment, the alpha-diversity of bacterial communities in plastisphere was lower, and the abundance of Actinobacteria increased. Plastic film residues, as bacterial habitats, exhibited greater heterogeneity and harbor unique bacterial communities. The communities were distinguished between plastisphere and soil environment by means of a random-forest (RF) machine-learning model. Prominent distinctions emerged among bacterial functions between soil environment and plastisphere, especially regarding organics degradation. The neutral model and null model indicated that the constitution of bacterial communities was dominated by random processes except in LDPE plastisphere. The bacterial co-occurrence network of the plastisphere exhibited higher complexity and modularity. This study contributes to our comprehending of characteristics of plastisphere bacterial communities in soil environment and the associated ecological risks of plastic film residues accumulation.

Supertoughened Polylactic Acid/Polybutylene Adipate Terephthalate Blends Compatibilized with Ethylene-Methyl Acrylate-Glycidyl Methacrylate: Morphology and Mechanical Properties by the Response Surface Methodology.

Optimized extrusion melt-blending of polylactic acid (PLA) polymer with a minor biopolymeric phase, polybutylene adipate terephthalate (PBAT), and compatibilized with random ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA, Trademark: Lotader AX-8900) led to an outstanding improvement in mechanical properties. At the noncompatibilized PLA-PBAT (80-20) blend point, significant enhancement (∼4500%) in toughness and elongation-at-break was already obtained without compromising any elastic properties. The effect of the compatibilizer content on the mechanical properties of the PLA-PBAT (80-20) blend was investigated by an optimal custom response surface methodology. Thus, 2 wt % Lotader content was determined to be optimal by a numerical optimization methodology with a desirability value, D, of 0.882 to maximize toughness and elongation-at-break. The compatibilization and thermal behavior of the Lotader-modified blends were analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Upon adding the compatibilizer, the original phase-separated morphology of the blends changed from PBAT quasi-spherical domains to nearly elongated elliptical ones. It was also found that the interfacial boundary line of the domains faded away, which revealed that interfacial compatibility was achieved. The thermostability of the blends remained largely unaltered following the incorporation of PBAT and Lotader. Moreover, while PBAT exhibited a minor influence on the crystallinity of PLA, Lotader had no discernible impact on crystallinity, as evidenced by the DSC thermograms. Thus, the compatibilizer at the optimal point in the optimized blend ratio led to the formation of a phase-separated morphology that combined internal cavitation, interfacial cavitation, and strong adhesion features at the right proportions in the microstructure which underlies the micromechanisms driving the remarkable enhancement of as much as 7100% in toughness and ductility.

Polybutylene adipate terephthalate (PBAT) composites for thermally conductive, fire retardant, high dielectric applications using BaTiO3 and MWCNTs as fillers

This study provides a comprehensive investigation of the fabrication of novel composite materials by blending polybutylene adipate terephthalate (PBAT) with barium titanate (BaTiO3) and multiwalled carbon nanotube (MWCNT) fillers. Prior to fabricating the composites, the filler surface treatments were tailored to enhance their compatibility with the PBAT matrix. Adipic acid (AA), a monomer for PBAT, was employed on the surface of the BaTiO3 particles, while butanediol (BD) also a monomer of PBAT was used to modify the surface of the MWCNTs to ensure effective interaction with the PBAT chains during the composite fabrication process. The composite samples were produced by melt-blending at 140 °C, followed by injection molding at the same operating temperature for subsequent analysis. The results revealed remarkable improvements in the dielectric constant, thermal conductivity, fire retardancy, and tensile strength of the 40 wt% BaTiO3 and MWCNT-PBAT blends compared to pure PBAT. The incorporation of BaTiO3 additionally contributed to enhanced fire retardancy, mechanical properties, and dielectric properties, making the composite material more resistant to ignition and flame spread, thus rendering it suitable for applications requiring elevated fire safety. In addition, the inclusion of MWCNT improved thermal conductivity, enabling promising and efficient heat dissipation in various applications.

Use of Zinc Oxide Nanoparticles Incorporated in Polybutylene Adipate Terephthalate for Food Packaging. A Focus on the Impact in Functional and Physic‐Mechanical Properties and on Migration Thereof

ABSTRACTPolybutylene adipate terephthalate (PBAT) and zinc oxide nanoparticles (ZnO NP) are among the most studied when it comes to address biodegradability and antimicrobial properties of materials for food packaging. This work presents a critical review of recent scientific literature with a focus on the impact in functional, physic‐mechanical properties, compostability and on safety. The properties of the nanoparticles, such as morphology and size reported are reviewed together with the range of concentrations and methods of incorporation in the PBAT matrix. The effect on antimicrobial and antioxidant activities, thermostability, tensile and optical properties, as well as on mass transfer properties (barrier to moisture and gases and migration into foods) is discussed. The properties of PBAT/ZnO depend on particle size, shape and concentration of the ZnO NP. Particles with higher surface area and smallest size are reported to have the best performance (usually the spherical shaped). However, information on the morphology/size of the nanoparticle is often not provided. The typical concentration of NP incorporation ranges from 0.5 to 5%, but the interpretation of results regarding the effect of concentration is highly limited due to poor information on the statistical significance of the results, particularly for low concentrations of incorporation. Another limitation found regards the film production method, because most of the studies are based in films prepared by solvent‐casting and not by extrusion. Antimicrobial activity is directly linked with the concentration of ZnO NP. Most studies applied in vitro experiments and not tests in real foods (in situ). Zinc migration can occur as the whole nanoparticle or in the ionic form. Studies indicate that migration of ZnO in the nano form is not expected if the nanoparticle is completely embedded in a polymeric matrix, which can be confirmed by some well‐established techniques. However, studies focusing on migration from other matrices are lacking. Further investigations are needed to achieve a balanced incorporation of ZnO NP considering the particle activity and zinc migration and to evaluate the impact on safety when used in food packaging.

Plastic Versus Bioplastic as Packaging for Sanitary Products: The Environmental Impacts Comparison

ABSTRACTPlastic or bioplastic? Which is the least impactful flexible packaging solution for the environment? In literature, few works try to answer this question, and most of them are focused on food packaging applications, comparing only polylactic acid (PLA) with polyethylene terephthalate (PET) or other virgin plastics. Besides these lacks in the literature, this work aims at contributing to the scientific knowledge, helping in the meanwhile packaging companies to choose the best solution also for hygienic and sanitary applications as far as the environmental impact is concerned. The study is focused on the life cycle assessment of four solutions made of maize starch, PLA and polybutylene adipate terephthalate (PBAT), low‐density polyethylene (LDPE) and a recycled LDPE (R‐LDPE). The functional unit was a flexible packaging containing 10 sanitary towels. Primary data were retrieved thanks to an Italian company, whereas secondary data were extracted from the Ecoinvent 3.7 database. The SimaPro 9.4 software has been used to calculate the global warming, water consumption, acidification and abiotic depletion of elements and fossil fuels of each packaging solution. The results show that the raw materials and packaging production are the most impactful phases during the life cycle of plastics and bioplastics packaging, if compared to the distribution phase, the auxiliary materials involved and the final disposal. Great benefits could be gained using recycled plastics, which allow to reduce the extraction of virgin materials and overall appear as the best solution from an environmental point of view to package also sanitary products.

Comparative Analysis of Biodegradable Mulches on Soil Bacterial Community and Pepper Cultivation

Biodegradable mulch films (BMFs) are becoming increasingly popular in agricultural practices. However, research on the ecological impact of biodegradable mulch films on pepper–soil systems is still scarce. To compare the differential effects of BMFs and polyethylene (PE) mulch on soil chemical properties, soil bacterial community composition, and pepper cultivation, a study was conducted encompassing eight distinct treatments. These treatments included three varieties of polybutylene adipate terephthalate (PBAT) combined with polylactic acid (PLA) mulches: PP-JL, PP-SD, and PP-SH; a black polypropylene carbonate mulch (PPC-BK); a brown PPC mulch (PPC-BR); a polyethylene (PE) mulch; straw mulching (NCK); and an uncovered control (PCK). After applying mulches for 129 days, most PPC and PBAT + PLA films had reached the rupture phase, whereas the PE film was still in the induction phase. Pepper yield was obviously higher in all mulched treatments (4830 kg hm−1) than in the un-mulched control (3290 kg hm−1), especially the BMF PP-JL treatment, which showed the most notable improvements in yield. Although BMF treatments maintained a lower soil temperature than the PE film mulch, they were still higher than the un-mulched control. Furthermore, the soil bacterial community composition and ecological network were not markedly affected by different mulching conditions. However, the PP-SH treatment significantly increased the abundance of Pseudomonas, Nitrosomonas, and Streptomyces genera. Moreover, Lactobacillus and Gp16 were substantially more abundant in the PPC-black (BK) and PPC-brown (BR) treatments compared to the PE mulching treatment. This study could provide valuable insights into the ecological benefits of BMFs in pepper cultivation. However, as our experiments were conducted for only one season, it is imperative to undertake long-term experiments across consecutive seasons and years for a thorough understanding and comprehensive study.

Environmental assessment of an innovative adhesive for the footwear industry: road map for product development

Abstract Purpose This work presents an environmental assessment of two adhesives to evaluate the replacement of the traditional adhesive (PU) used in the footwear industry by a novel adhesive based on a microencapsulation approach (PUMC) which is more favorable from the safety and technical perspectives. The PU adhesive is polyurethane-based, while the PUMC adhesive is polyurethane-based but with its isocyanate compounds microencapsulated, increasing storage life and reducing risks related to the exposure of workers with the adhesives. Methods The potential environmental impact of the adhesives was evaluated using the life cycle assessment (LCA) methodology. A detailed process model was developed (both for laboratory and for a pilot-scale implementation) to investigate the environmental impacts associated with these processes. The functional unit was one kilogram of adhesive (PU and PUMC adhesives) produced. A cradle-to-customers’ gate approach was defined. The system boundary starts from extraction of resources, through material production, until adhesive use. This includes microcapsule production in the case of the PUMC adhesive. This study investigates the important drivers behind the environmental impacts to help guide commercialization efforts. A scenarios study/sensitivity analysis was conducted to determine the response of the PUMC adhesive system to the variability of the model, scenarios, and parameters. Results The results show that the PU adhesive environmental impact is due to acetone and polyol consumption in the production stage. In the PUMC adhesive system, acetone consumption and microcapsule production are the major factors responsible for the environmental impact. Polybutylene adipate terephthalate (PBAT), dichloromethane (DCM), and isophorone diisocyanate (IPDI) consumption are the major factors responsible for the environmental impact of the microcapsules’ production. A sensitivity analysis was conducted using three alternative scenarios focused on the reduction in material consumption and increase in material recuperation, as well as using an alternative renewable energy source. Although the traditional PU adhesive has a lower impact, it was found that the three alternative PUMC adhesive systems can become comparable to the traditional PU adhesive. Conclusions This study shows the advance and development of a new technology for microencapsulation of isocyanate in adhesives and its environmental advantages and disadvantages with respect to a traditional product that uses non-encapsulated isocyanate. Finally, it was shown that there is significant potential for minimizing some environmental impacts of the PUMC adhesive, such as optimizing the microcapsules’ production stage, increasing the production efficiency to decrease the required material consumption.

Effects of a phosphorus-nitrogen containing DOPO derivative on the flame retardancy and mechanical properties of polylactic acid foamed materials

In this study, a phosphorus-nitrogen flame retardant (DOPO-DABP) was synthesized by 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and 4,4′-diaminobenzophenone (DABP). Then, polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), ammonium polyphosphate (APP), DOPO-DABP, Joncryl ADR-4370F(ADR), azodicarbonamide (ADC) and nano-SiO2 were used as raw materials to prepare flame-retardant modified PLA foamed materials by hot pressing. The synergistic effect of APP and DOPO-DABP not only effectively improves the flame retardancy of PLA foamed material, but also promotes their mechanical properties. The experimental results showed that when APP/DOPO-DABP=10/10, the vertical combustion grade (UL-94) of the material reached the V-0 level, the limiting oxygen index (LOI) was 34.4 %. The tensile strength of the material was 25.35 MPa, bending strength was 32.14 MPa. The cell diameter of the material was reduced to 46.72 μm, and the cell density of the material was 2.25×106/cm3.

FDM 3D Printing and Properties of PBAT/PLA Blends.

Biodegradable polylactic acid (PLA) has been widely used in fused deposition modeling (FDM) 3D printing. In order to improve its comprehensive properties in 3D printing, in this study, 0-40% content of polybutylene adipate terephthalate(PBAT) was selected to be blended with PLA in a twin-screw extruder; the resulting pellets were drawn into a homogeneous filament; then, PBAT/PLA samples were prepared by FDM 3D printing, and the effects of the dosage of PBAT on the mechanical properties, thermal behavior, surface wettability and melt flowability of the samples were investigated. The results showed that all the samples could be printed smoothly, and the ductility was slightly improved by the increase in the PBAT dosage; the thermal stability of PLA was enhanced by blending with PBAT, and the crystallinity increased monotonically with the increase in PBAT. After blending with PBAT, the surfaces of the samples were more hydrophilic and flowable. The important conclusion achieved in this work was that the PBAT/PLA blends, especially those containing 30%PBAT, showed great potential to replace petroleum-based plastics and are suitable for use in FDM 3D printing technologies for different applications.

Metagenomic investigations into the microbial consortia, degradation pathways, and enzyme systems involved in the biodegradation of plastics in a tropical lentic pond sediment.

The exploitation of exciting features of plastics for diverse applications has resulted in significant plastic waste generation, which negatively impacts environmental compartments, metabolic processes, and the well-being of aquatic ecosystems biota. A shotgun metagenomic approach was deployed to investigate the microbial consortia, degradation pathways, and enzyme systems involved in the degradation of plastics in a tropical lentic pond sediment (APS). Functional annotation of the APS proteome (ORFs) using the PlasticDB database revealed annotation of 1015 proteins of enzymes such as depolymerase, esterase, lipase, hydrolase, nitrobenzylesterase, chitinase, carboxylesterase, polyesterase, oxidoreductase, polyamidase, PETase, MHETase, laccase, alkane monooxygenase, among others involved in the depolymerization of the plastic polymers. It also revealed that polyethylene glycol (PEG), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polyethylene terephthalate (PET), and nylon have the highest number of annotated enzymes. Further annotation using the KEGG GhostKOALA revealed that except for terephthalate, all the other degradation products of the plastic polymers depolymerization such as glyoxylate, adipate, succinate, 1,4-butanediol, ethylene glycol, lactate, and acetaldehyde were further metabolized to intermediates of the tricarboxylic acid cycle. Taxonomic characterization of the annotated proteins using the AAI Profiler and BLASTP revealed that Pseudomonadota members dominate most plastic types, followed by Actinomycetota and Acidobacteriota. The study reveals novel plastic degraders from diverse phyla hitherto not reported to be involved in plastic degradation. This suggests that plastic pollution in aquatic environments is prevalent with well-adapted degrading communities and could be the silver lining in mitigating the impacts of plastic pollution in aquatic environments.

Effects of Conventional Non-Biodegradable Film-Derived Microplastics and New Biodegradable Film-Derived Microplastics on Soil Properties and Microorganisms after Entering Sub-Surface Soil

Plastic film mulching, widely used in agriculture, leads to microplastic (MP) pollution in soils. While biodegradable polybutylene adipate terephthalate (PBAT) films may offer a solution, their impacts on subsurface soils and microorganisms remain unclear. To investigate the effects of conventional non-biodegradable polyethylene (PE) and biodegradable PBAT MPs on the properties of sub-surface soils and microbial communities, MPs were added at varying doses in a field experiment and incubated for 160 days. Physicochemical characteristics, nutrient dynamics, and microbial composition, diversity, and networks of soils were analyzed using standard techniques and 16S rRNA/ITS gene sequencing. Correlations between soil properties and microbes were assessed. Both MP types significantly altered soil characteristics, with PBAT-MP elevating pH and the levels of available phosphorus and potassium more than PE-MP. Microbial composition shifts occurred, with low-addition PBAT-MP promoting plastic-degrading genera. The assessment of α/β-diversity indicated that PBAT-MP predominantly influenced fungi while PE-MP impacted bacteria. An examination of microbial co-occurrence networks highlighted that PE-MP primarily disrupted fungal interactions, whereas PBAT-MP streamlined network complexity. Correlation analyses revealed that PBAT-MP promoted fungal diversity/network resilience correlating to nutrients. PE-MP and PBAT-MP significantly altered native soil/microbe relationships. PBAT-MP may exert greater, yet unknown, impacts over time through its biodegradation into newer and smaller fragments. Future research needs to integrate multi-omics and stable isotope science to elucidate the deep mechanistic impacts of degraded film-derived MPs on microbial ecological functions and biogeochemical cycles. Attention should also be paid to the long-term accumulation/transport of MPs in agricultural soils. Overall, this work deepens the impact and understanding of MPs from plastic film on sub-surface soil ecology. Furthermore, it provides a theoretical foundation for managing ‘white pollution’ in the film-covered farmlands of arid and semi-arid regions in China.

Preparation and Mechanical Properties of PBAT/Silanized Cellulose Composites

Polybutylene adipate-terephthalate (PBAT) is a fully biodegradable polyester, which has been proven to be the most suitable alternative to traditional plastics. However, due to the low strength of PBAT (17.2 MPa) and high price, the use of PBAT has a degree of limitations. To obtain a cost-effective and high-performance composite material of PBAT, for this study we selected microcrystalline cellulose, which is inexpensive and easily available, as the reinforcing medium. However, due to the hydrophobicity of PBAT, the mechanical properties of PBAT when mixed with hydrophilic cellulose were low. In order to improve the compatibility of cellulose and PBAT, this study selected hexadecyltrimethoxysilane (HDTMS) containing long carbon chains to silanize microcrystalline cellulose (MCC) to obtain silanized cellulose (SG). Three types of SGs with different degrees of silanization were obtained by controlling HDTMS with different mass ratios (1:10; 3:10; 5:10) to react with MCC. Characterization of these three types of SGs was conducted using FTIR, TEM, and water absorption analysis. The results demonstrated the successful synthesis of SG. With the increase in the reaction ratio of HDTMS and MCC, the size of the nanoparticles increases, and the water absorption decreases significantly. Subsequently, PBAT/SG composites were prepared by blending three kinds of silanized cellulose with PBAT in different proportions by the sol-gel method. To study the thermal stability and compatibility, the mechanical properties of the composites were evaluated, including thermogravimetric testing, scanning analysis, and dynamic thermomechanical testing. The optimal blending ratio and the optimal type of silane cellulose were found. Analysis of the mechanical properties revealed that the tensile strength initially increased and then decreased with increasing blending ratio for all three composites tested. Among them, the PBAT/SG2 composites exhibit superior performance, with a maximum tensile strength reaching 22 MPa at an 85/15 blending ratio, nearly 30% higher than that of pure PBAT alone. The addition of SG significantly improved the strength of the PBAT, and SG2 is more suitable for preparing high-strength composite materials. In addition, after the addition of SG, the yield stress of the composite is improved while maintaining good thermal stability. Both the SEM and DMA results indicated good compatibility of the PBAT/SG composites. This study provides a new idea for the industrial-scale development of degradable polyesters with low cost and good mechanical properties.

Exploring the potential of earthworm gut bacteria for plastic degradation

The use of plastic mulch films in agriculture leads to the inevitable accumulation of plastic debris in soils. Here, we explored the potential of earthworm gut-inhabiting bacterial strains (Mycobacterium vanbaalenii (MV), Rhodococcus jostii (RJ), Streptomyces fulvissimus (SF), Bacillus simplex (BS), and Sporosarcina globispora (SG) to degrade plastic films (⌀ = 15 mm) made from commonly used polymers: low-density polyethylene film (LDPE-f), polylactic acid (PLA-f), polybutylene adipate terephthalate film (PBAT-f), and a commercial biodegradable mulch film, Bionov-B® (composed of Mater-Bi, a feedstock with PBAT, PLA and other chemical compounds). A 180-day experiment was conducted at room temperature (x̄ =19.4 °C) for different strain–plastic combinations under a low carbon media (0.1× tryptic soy broth). Results showed that the tested strain–plastic combinations did not facilitate the degradation of LDPE-f (treated with RJ and SF), PBAT-f (treated with BS and SG), and Bionov-B (treated with BS, MV, and SG). However, incubating PLA-f with SF triggered a reduction in the molecular weights and an increase in crystallinity. Therefore, we used PLA-f as model plastic to study the influence of temperature (“room temperature” & “30 °C”), carbon source (“carbon-free” & “low carbon supply”), and strain interactions (“single strains” & “strain mixtures”) on PLA degradation. SF and SF + RJ treatments significantly fostered PLA degradation under 30 °C in a low-carbon media. PLA-f did not show any degradation in carbon-free media treatments. The competition between different strains in the same system likely hindered the performance of PLA-degrading strains. A positive correlation between the final pH of culture media and PLA-f weight loss was observed, which might reflect the pH-dependent hydrolysis mechanism of PLA. Our results situate SF and its co-culture with RJ strains as possible accelerators of PLA degradation in temperatures below PLA glass transition temperature (Tg). Further studies are needed to test the bioremediation feasibility in soils.

High-performance and economic biodegradable composites based on polybutylene adipate terephthalate and modified lignin

Polybutylene adipate terephthalate (PBAT) is a biodegradable polymer with promising properties, but its wide-spread application is limited by factors such as high cost, suboptimal mechanical characteristics, and slow biodegradation rate. In this study, these limitations are addressed by incorporating low-cost lignin, modified with an isocyanate compound, into PBAT via an extrusion process. By investigating the effects of varying isocyanate content on the lignin surface, the optimal modification conditions at room temperature are identified over 48 h. Additionally, the maximum lignin content (5 wt%) is determined within the composite to achieve a balance between mechanical, thermal, and biodegradation properties while also considering the economic and environmental feasibility of the polymer composite. The research delved into the examination of both the minimum selling price (MSP) and global warming potential (GWP) for all PBAT-mLigA composites. The optimized PBAT-mLigA composites exhibited a notable reduction of up to 7% in both MSP and GWP when compared to pure PBAT. The predominant determinants influencing the economic and environmental potentials of these composites are the pricing of PBAT and the ratio in which it is incorporated into the proposed composites.

An assessment of the role of nanosilica in thermal/thermo‐oxidative degradation mechanism of poly(lactic acid)/polybutylene adipate terephthalate blend nanocomposites

AbstractAs a packaging materials candidate, based on a polylactic acid/ polybutylene adipate terephthalate (PLA/PBAT) blends (90/10 and 75/25 wt/wt) containing 1, 3, and 5 phr hydrophilic (HPL) and hydrophobic (HPB) nanosilica (NS) particles in the presence of a multifunctional epoxide compatibilizer were prepared by melt mixing, in a twin‐screw extruder. Scanning electron microscopic studies confirmed a matrix‐droplet morphology with finer dispersed domains at higher NS content. Energy dispersive spectroscopy mapping also indicated uniform dispersion of NS in blends, with some agglomerates at higher content of nanoparticles. Moreover, transmission electron microscope was applied to study the impact of nanofillers' localization on the systems' morphology. It was observed that NS particles localized at the PLA‐PBAT interface. In addition, thermogravimetric analysis (TGA) was used to investigate thermal stability and thermal degradation kinetics. Data indicates that hydrophobic NS improved thermal stability. The activation energy of degradation was calculated using several techniques of data modeling, including Friedman, Flynn‐Ozawa‐Wall, and Kissinger‐Akahira‐Sunose models. Among blend nanocomposites, 75/25 blend containing 5 phr HPB NS had the maximum degradation activation energy, suggesting that this sample had the most resistance to heat degradation. The intensity of the TGA/FTIR peaks of the evolved products was found to be correlated with the activation energy. The Criado's technique was also used to investigate the changes in the thermal degradation mechanism.

Mature compost promotes biodegradable plastic degradation and reduces greenhouse gas emission during food waste composting

Mature compost can promote the transformation of organic matter (OM) and reduce the emission of polluting gases during composting, which provides a viable approach to reduce the environmental impacts of biodegradable plastics (BPs). This study investigated the impact of mature compost on polybutylene adipate terephthalate (PBAT) degradation, greenhouse gas (GHG) emission, and microbial community structure during composting under two treatments with mature compost (MC) and without (CK). Under MC, visible plastic rupture was advanced from day 14 to day 10, and a more pronounced rupture was observed at the end of composting. Compared with CK, the degradation rate of PBAT in MC was increased by 4.44 % during 21 days of composting. Thermobifida, Ureibacillus, and Bacillus, as indicator species under MC treatment, played an important role in PBAT decomposition. Mature compost reduced the total global warming potential (GWP) by 25.91 % via inhibiting the activity of bacteria related to the production of CH4 and N2O. Functional Annotation of Prokaryotic Taxa (FAPROTAX) further revealed that mature compost addition increased relative abundance of bacteria related to multiple carbon (C) cycle functions such as methylotrophy, hydrocarbon degradation and cellulolysis, inhibited nitrite denitrification and denitrification, thus alleviating the emission of GHGs. Overall, mature compost, as an effective additive, exhibits great potential to simultaneously mitigate BP and GHG secondary pollution in co-composting of food waste and PBAT.

Effects of different biopolymers and additives on mechanical and barrier properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) blend films

Bio-based materials could offer solutions to the problems of petroleum-derived material usage and waste management. By taking into consideration this fact, the aim of this study was to create alternative product recipes for flexible packaging with the use of biodegradable polymers in line with sustainable packaging targets. In this study, the exit point was to prepare polybutylene adipate terephthalate (PBAT) and polyhydroxyalkanoate (PHA)-based bioblends with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by solution casting method in order to create biocomposite combination for flexible packaging with improved properties. Hydroxypropyl methylcellulose (HPMC) additive was used to enhance barrier properties. Thermal, mechanical, optical properties, oxygen permeability, water vapor transmission rate, and morphological features of the resultant biocomposites were characterized. First of all, it was seen that the elongation at break and tensile strength properties of single biopolymers can be combined in binary structures. Then, by establishing triple blend structures, biocomposite films with improved properties were obtained. In addition, the effects of alternative polybutylene succinate (PBS) and polylactic acid (PLA) biopolymers to PBAT biopolymer in triple bioblends were examined. As a result of the studies it was found that the PHBV/PBAT/PHA structure could be developed with functional additives in order to reach the best flexible packaging formula. It was found that the oxygene transmission rate (OTR) value was improved compared to PE with PHA, PHBV and HPMC additives, decreased to 29 cc/m2.day with PBS and 14 cc/m2.day with PLA added to the structure.

Effects of biodegradable microplastics on arsenic migration and transformation in paddy soils: a comparative analysis with conventional microplastics

The combined pollution of microplastics (MPs) and arsenic (As) in paddy soils has attracted more attention worldwide. However, there are few comparative studies on the effects of biodegradable and conventional MPs on As migration and transformation. Therefore, conventional (polystyrene, polyethylene, polyvinyl chloride) and biodegradable (polybutadiene styrene, polylactic acid, polybutylene adipate terephthalate) MPs were selected to explore and demonstrate their influences and mechanism on As migration from paddy soils to overlying water and As speciation transformation through microcosmic experiment with measuring the changes of As chemical distribution, physicochemical indexes and microbial community in paddy soils. The results showed that biodegradable MPs enhanced As migration and transformation more effective than conventional MPs during 60 d. Biodegradable MPs indirectly increased the content of As(Ⅲ) and bioavailable As by changing the microbial community structure and affecting the biogeochemical cycles of carbon, nitrogen, sulfur and iron in soils, and promoted the As migration and transformation. PBS showed the strongest promoting effect, transforming to more As(Ⅲ) (11.43%) and bioavailable As (4.28%) than control. This helps to a better understanding of the effects of MPs on As biogeochemical cycle and to clarify the ecological and food safety risks of their combined pollution in soils.

Enhancing methane production potential of biodegradable plastics by hydrothermal pretreatment

Anaerobic digestion (AD) is considered a promising method to treat biodegradable plastic (BP) wastes, while low CH4 production yields (MPYs) of BPs limit field application of AD. To overcome such limitation, the impact of hydrothermal pretreatment (HTP) on MPYs of four commercial BPs such as polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS) was investigated in this study. Solubilization efficiencies of BPs increased as BPs were pretreated under higher temperature and longer duration. After pretreatment at 150 °C for 3 hr, MPYs of PLA, PHA, PBAT, and PBS under mesophilic conditions were 450–460, 530–545, 165–175, and 460–490 L CH4/kg VS, respectively, which were significantly higher than one of untreated BPs. Pretreatment temperature was found to be the most important parameter affecting CH4 production from BPs compared to pretreatment duration and particle size. It was confirmed that HTP could depolymerize the long polymeric chain in BPs into the monomers of each BP, such as lactate, 2-butenoic acid, 1,4-butanediol, and succinic acid, together with significant changes in surface characteristics. Such changes might be the main reasons for enhancing CH4 production from BPs. These results suggest that the application of HTP to AD can potentially offer to treat diverse BP waste simultaneously with high CH4 production efficiency.

Biopolymer composites based on ultrasound/plasma‐modified fiber waste and polybutylene adipate terephthalate (PBAT): Physicochemical and functional performance

AbstractA strategy for a circular economy is to reuse and modify agricultural wastes through green methodologies, which can be employed as high‐value raw materials to produce sustainable materials. Thus, polybutylene adipate terephthalate (PBAT) composites containing plasma (P) and ultrasound/plasma (UP) modified Agave fibers (AF) were prepared by the melt mixing process. The effect of content (10% and 20%) and type of fiber on the processing, structural, mechanical, and water barrier performance of PBAT composites was assessed. FTIR analysis exhibited the presence of O‐Si‐O groups in all composites containing modified AF, indicating the presence of nanometric hexamethyldisiloxane (HMDSO) coating on the fiber surface. The addition of modified AF into PBAT polymer promoted higher torque levels and specific energy during the composites processing, indicating higher matrix‐fiber interactions that hindered the free flow of the polymeric chains. Nevertheless, SEM, DSC, and crystallinity results revealed that PBAT‐AFUP composites exhibited more homogeneous surfaces and ordered structures that promoted higher entanglement between modified fibers and the PBAT matrix and restricted the binding sites for water interaction as changes in tensile modulus (from 90 to 163 MPa) and water contact angle (from 63 to 77°) indicated. These findings show that modified Agave fibers are a sustainable raw material that can be easily processed to produce soft and hydrophobic PBAT‐based composites.Highlights The fiber type determined the functional performance of the PBAT composites The modified fibers increased the entanglement of composite chains UP‐modified fibers improved the water barrier performance of the PBAT matrix