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Rationale: Plastic mulch film manages weed growth and moisture loss on the surface of cropping beds. The chemical components of such plastics include polymer(s), additives and non‐intentionally added substances (NIASs). The unknown chemical nature and behaviours of these constituents require investigation due to their potential to add to the anthropogenic chemical burden in the agrifood system. Methods: Solvent extracts of a commercial 15% polylactic acid (PLA)/85% poly(butylene adipate‐co‐terephthalate) mulch film were investigated using gas chromatography–mass spectrometry (GC–MS) with electron ionisation to characterise the additive and NIAS components. The obscurity of some of the NIASs meant their identification was not readily achieved through routine MS library comparisons. As such, the identification of several polymer‐derived compounds required interpretation of the MS data and re‐application of the derived fragmentation patterns with reference to the wider literature. Unknowns were confirmed using commercially available compounds. Results: Unknown NIASs were identified as cyclic oligoesters comprised of the monomeric building blocks of the polymer system. Cyclic structures derived from the monomers of polybutylene adipate (PBA) and polybutylene terephthalate (PBT) fragmented through a primary pathway involving 1,5‐ and 1,3‐H transfers at ester linkages. Characteristic ions at m/z 111, 129, 183 and 201 for PBA‐derived cyclic oligoesters and m/z 104, 132, 149 and 221 for PBT‐derived cyclic oligoesters were assigned in the mass spectra of unknowns. Cyclic oligoesters containing sebacate moieties were also identified, indicating the presence of polybutylene sebacate as an unexpected component of the mulch. Conclusions: Systematic analyses of the sort reported here are valuable for providing alternative approaches for the identification of plastic‐related chemicals. Open publication of MS spectral data is required to build a greater understanding of the mulch film chemical components contributing to the environmental chemical load introduced to agroecosystems. [ABSTRACT FROM AUTHOR]

Detecting, separating, and characterizing airborne microplastics from other airborne particulates is currently challenging due to the various instrumental constraints and related sample preparation hurdles that must be overcome. The ability to measure these real-world environments is needed to better assess the risks associated with microplastics. To that end, the current study focused on developing a methodology for sampling and characterizing airborne microplastics. Particulate sampling was carried out at a municipal materials recovery facility near a conveyer belt containing sorted plastic materials to collect airborne environmental particles on filters. Nucleopore filters were mounted on Teflon support rings, coated with 100 nm aluminum to reduce the background signal for micro-Raman spectroscopy, and marked with a fiducial pattern using a laser engraver. The fiducial pattern was crucial in identifying samples, relocating particles, and efficiently enabling orthogonal measurements on the same samples. Optimum sampling conditions of 2 h at 25 L/min were determined using light microscopy to evaluate the particle loadings. The filters were then cut into slices which were attached to sections of thin beryllium-copper sheeting for easy transfer of the filter between microscopy platforms. Scanning electron microscopy was used to identify carbon-rich particles. Light microscopy was used to identify colored particles which were also carbon-rich which were then analyzed using micro-Raman spectroscopy to identify specific polymers. [ABSTRACT FROM AUTHOR]

This study presents a novel hydrophobic lignocellulosic bioplastic from corn stover reinforced by oxidized cellulose and in situ regenerated lignin. Cellulose‐lignin mixture as a matrix was obtained by acid‐recyclable deep eutectic solvent (DES) pretreatment of corn stover in mild conditions. Triethoxy(octyl)silane (C14H32O3Si) was employed to improve the water stability of the bioplastic by vapor deposition. The results show that the hydrophobic bioplastic has a high tensile strength, measuring 62.36 MPa. The water contact angle of the bioplastic was increased from 8.50° to 121.9° after hydrophobic modification. We prepared oxidized cellulose‐reinforced cellulose paper by different particle size distributions of oxidized cellulose to investigate the reinforcement of oxidized cellulose. The tensile strength of oxidized cellulose cellulose paper increased from 14.41 to 21.18 MPa with the addition of oxidized cellulose. The zeta potential of oxidized cellulose is −47.99 mV, which shows a more negative charge due to carbonyl groups. The repulsive force of oxidized cellulose contributes to the formation of a brick‐and‐mortar microstructure with cellulose‐lignin mixture. It demonstrates that oxidized cellulose can act as bio‐adhesives and has a good toughening effect on the mechanical properties of bioplastic. Highlights: Lignocellulosic bioplastic was prepared by DES pretreatment of corn stover.Oxidized cellulose was used to reinforce the lignocellulosic bioplastic.The tensile strength of the bioplastic was 62.36 MPa after the reinforcement process.Trieth‐oxy(octyl)silane was employed to improve water stability.The water contact angle of the bioplastic was increased from 8.50° to 121.9°. [ABSTRACT FROM AUTHOR]

α-zeins are amphiphilic maize seed storage proteins with material properties suitable for a multitude of applications e.g., in renewable plastics, foods, therapeutics and additive manufacturing (3D-printing). To exploit their full potential, molecular-level insights are essential. The difficulties in experimental atomic-resolution characterization of α-zeins have resulted in a diversity of published molecular models. However, deep-learning α-zein models are largely unexplored. Therefore, this work studies an AlphaFold2 (AF2) model of a highly expressed α-zein using molecular dynamics (MD) simulations. The sequence of the α-zein cZ19C2 gave a loosely packed AF2 model with 7 α-helical segments connected by turns/loops. Compact tertiary structure was limited to a C-terminal bundle of three α-helices, each showing notable agreement with a published consensus sequence. Aiming to chart possible α-zein conformations in practically relevant solvents, rather than the native solid-state, the AF2 model was subjected to MD simulations in water/ethanol mixtures with varying ethanol concentrations. Despite giving structurally diverse endpoints, the simulations showed several patterns: In water and low ethanol concentrations, the model rapidly formed compact globular structures, largely preserving the C-terminal bundle. At ≥ 50 mol% ethanol, extended conformations prevailed, consistent with previous SAXS studies. Tertiary structure was partially stabilized in water and low ethanol concentrations, but was disrupted in ≥ 50 mol% ethanol. Aggregated results indicated minor increases in helicity with ethanol concentration. β-sheet content was consistently low (∼1%) across all conditions. Beyond structural dynamics, the rapid formation of branched α-zein aggregates in aqueous environments was highlighted. Furthermore, aqueous simulations revealed favorable interactions between the protein and the crosslinking agent glycidyl methacrylate (GMA). The proximity of GMA epoxide carbons and side chain hydroxyl oxygens simultaneously suggested accessible reactive sites in compact α-zein conformations and pre-reaction geometries for methacrylation. The findings may assist in expanding the applications of these technologically significant proteins, e.g., by guiding chemical modifications. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA), a biomass material, has garnered increasing interest as a biodegradable alternative for the production of eco-friendly plastics. Accordingly, the sustainable synthesis of lactic acid (LA) and its derivatives from biomass sources is emerging as a viable approach. In this work, an In-TS-1 zeolite with exceptional catalytic activity and stability was successfully synthesized using a hydrothermal method and applied for the efficient one-pot conversion of fructose into methyl lactate (MLA). Characterization of the resulting catalysts, including pyridine-adsorbed Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, and energy dispersive X-ray spectroscopy for elemental mapping, confirmed that the uniform dispersion of indium (In) species contributed to its favorable acidity and significantly boosted the reaction efficiency. Under optimized reaction conditions, a remarkable MLA yield of 71.9% was achieved upon the complete conversion of fructose. The selectivity of MLA remained consistent over 14 cycles, underscoring its extraordinary stability under hydrothermal conditions attributed to the confinement of In species within the zeolite framework. This research technique establishes a potential strategy for the large-scale manufacture of LA and its esters, offering a sustainable and efficient path for the development of biodegradable plastics. [ABSTRACT FROM AUTHOR]

This review article provides a thorough overview of barrier coating materials that have been used in food packaging with a focus on biodegradable (bio-based or petroleum-based) materials, such as lipids, proteins, polysaccharides, agriculture waste and polyesters. The goal is to provide an opportunity to acknowledge progress made in this field, focusing on modifications made to coatings. These modifications aim to address the shortcomings of biodegradable substrates (either plastic or paper) and improve their performance, enabling them to compete with traditional petroleum-based food packaging materials. This includes their barrier against water vapor and oxygen, mechanical and surface characteristics (sealability and adhesion), as well as antimicrobial properties. The barrier of most biodegradable polymers underperforms in comparison with petroleum-based non-biodegradable polymers, which possess either high water vapor barrier or high oxygen barrier. Coating technology is a promising solution particularly in barrier improvement of biodegradable polymers. Currently, there are only metallized, or inorganic nanosheet coatings available for biodegradable films that meet food packaging requirements. There are some challenges in this field, for example, being able to retain the coating's biodegradability despite applied modifications to improve it's performance, the large-scale fabrication of biodegradable coatings, the coating's delamination and heat-sealability during service time, and the migration of the coating into the packaged food. Moreover, green chemistry and its sustainability needs in biodegradable polymeric coatings are also discussed regarding new ideas and possible directions for widespread application of coatings in food packaging. This is the first review that specifically summarizes biodegradable coatings on plastic and paper substrates with a focus on coating modifications to improve the performance of the base substrate to meet the required properties for food packaging applications. [ABSTRACT FROM AUTHOR]

Microbeads find widespread usage in personal care items and cosmetics, serving as exfoliants or scrubbing agents. Their micro-scale size poses challenges in effective drainage capture and given their origin from non-biodegradable oil-based plastics, this contributes substantially to marine pollution. In this study, microbeads were prepared by a simple yet scalable melt homogenization method using four types of polyhydroxyalkanoates (PHA), namely poly[(R)-3-hydroxybutyrate] (P(3HB)), poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (P(3HB-co-3HV)), poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (P(3HB-co-3HHx)) and poly[(R)-3-hydroxybutyrate-co-(R)-4-hydroxyvalerate] (P(3HB-co-4HB)). Microbeads with different surface smoothness, compressive strength (6.2–13.3 MPa) and diameter (from 1 ~ 150 μm) could be produced. The microbeads were subjected to a comprehensive degradation analysis using three techniques: enzymatic, Biochemical Oxygen Demand (BOD) evaluations, and in situ degradation tests in the deep-sea off Misaki Port in the northern Pacific Ocean (depth of 757 m). Qualitatively, results from enzymatic and in situ degradation demonstrated significant degradation within one week and five months, respectively. Quantitatively, BOD findings indicated that all PHA microbeads degraded similarly to cellulose (~ 85% biodegradability in 25 days). In conclusion, PHA microbeads from this study exhibit promising potential as alternatives to conventional non-biodegradable microbeads. [ABSTRACT FROM AUTHOR]

2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable pseudo-aromatic dicarboxylic acid, is a promising building block compound for manufacturing biodegradable polyesters. This study aimed to construct high-performance cell factories enabling the efficient production of PDC from glucose. Firstly, the effective enzymes of the PDC biosynthetic pathway were overexpressed on the chromosome of the 3-dehydroshikimate overproducing strain. Consequently, the one-step biosynthesis of PDC from glucose was achieved. Further, the PDC production was enhanced by multi-copy integration of the key gene PsligC encoding 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase and co-expression of Vitreoscilla hemoglobin. Subsequently, the PDC production was substantially improved by redistributing the metabolic flux for cell growth and PDC biosynthesis based on dynamically downregulating the expression of pyruvate kinase. The resultant strain PDC50 produced 129.37 g/L PDC from glucose within 78 h under fed-batch fermentation conditions, with a yield of 0.528 mol/mol and an average productivity of 1.65 g/L/h. The findings of this study lay the foundation for the potential industrial production of PDC. • Biosynthesis of PDC from glucose was achieved in E. coli by combinatorial pathway engineering. • Heterologous expression of hemoglobin was used to increase PDC production. • Dynamic downregulation of pykA was employed to balance cell growth and PDC biosynthesis. • An efficient cell factory enabling potential industrial production of PDC was constructed. [ABSTRACT FROM AUTHOR]

In the recent decade, nanoparticles (NPs) have had enormous implications in cancer biomedicine, including research, diagnosis, and therapy. However, their broad application still faces obstacles due to some practical limitations and requires further development. Recently, there has been more interest in the coated class of nanoparticles to address those challenges. Chitosan‐coated NPs are simple to produce, biodegradable, biocompatible, exhibit antibacterial activity, and have less cytotoxicity. This study provides an updated and comprehensive overview of the application of chitosan‐coated NPs as a promising class of NPs in cancer biomedicine. Additionally, we discussed chitosan‐coated lipid, metal, and polymer‐based nanoparticles in biomedical applications. Furthermore, different coating methods and production/characterization procedures were reviewed. Moreover, the biological and physicochemical advantages of chitosan‐coated NPs, including facilitated controlled release, greater physicochemical stability, improved cell/tissue interaction, and enhanced bioavailability of medications, were highlighted. Finally, the prospects of chitosan‐coated NPs in cancer biomedicine were discussed. [ABSTRACT FROM AUTHOR]

A nonthermal, pulsed spark discharge is applied to three polymer powders in Ar and Ar–H2 ${{\rm{H}}}_{2}$ gas mixtures. Hydrogen is introduced to assess plasma‐driven decomposition. Gaseous decomposition products, including methane, acetylene, and ethylene, are observed with Fourier‐transform infrared (FTIR). Surface modifications are observed on the residual polymer via attenuated total internal reflection‐FTIR. Time‐averaged rotational, vibrational, and excitation temperatures are characterized in the discharge. The plasma density is found to be around 3×1022 m−3 $3\times 1{0}^{22}\unicode{x0200A}{{\rm{m}}}^{-3}$, with rotational and vibrational temperatures ranging from 1500 to 2200 K and an excitation temperature of 1–2 eV. While spark properties did not change with either gas composition or polymer composition, it was determined that the addition of hydrogen promoted higher concentrations of gaseous phase products (promoting hydrogenolysis). [ABSTRACT FROM AUTHOR]

The topic of riverine microplastics is of great interest to the general public, yet the univocal scientific knowledge on this topic is limited. This review investigated the occurrence of microplastics in 6 major European rivers and their tributaries based on the results from 29 studies. We examined the reviewed studies in regard to data quality and reproducibility and assessed the abundance of microplastics in different sections of the water column. Furthermore, we investigated the chemical composition and potential origin of the reported riverine microplastics. We found that polystyrene, polypropylene, and polyethylene were the most abundant polymer types. The majority of primary microplastics arose from the industry sector as well as from personal care and cleaning products, whereas secondary microplastics constituted fibers from synthetic textiles and fragments of diverse origins. We highlighted the diversity of experimental and analytical approaches that could lead to high uncertainties in the measurements of microplastics abundance. Furthermore, the presence of microplastics in rivers was found to vary spatially likely due to point and nonpoint pollution sources of anthropogenic activities. Heterogenous environmental processes impacted the fate of microplastics characterized by various forms, sizes, and densities, in different ways. This impeded the identification of representative quantitative measurements of microplastics across different time frames. We advocate for the development of standardized protocols by the research community to ensure higher reproducibility of sampling, processing, and analysis of microplastics in aquatic environments. We recommend long‐term and site‐specific monitoring on microplastics with high data comparability to better inform policy making. This article is categorized under:Science of Water > Water QualityWater and Life > Conservation, Management, and Awareness [ABSTRACT FROM AUTHOR]

In light of increasing apprehensions surrounding the environmental impact of non-biodegradable plastics, there has been a surge in the exploration of biodegradable films as a viable and sustainable alternative. This research has focused on developing Tara gum (TG)-based films incorporated with Lavender essential oil (LEO) at different concentrations (5–20% w/w) to improve the properties of the films. According to the results, GC-MS analysis confirmed the presence of linalool and linalyl acetate as the major compounds in LEO. Among the composite films, the sample containing 5% (w/w) LEO exhibited the highest homogeneity, as evidenced by SEM micrographs, and the CLSM image demonstrated the absence of any clustering or coalescence of LEO within this film. FTIR spectra demonstrated intermolecular interactions between TG and LEO, as evidenced by a new peak at 1458 cm−1 in the LEO-loaded films. The addition of LEO resulted in a significant decrease in the water content (WC) and water solubility (WS) of the films. Furthermore, LEO incorporation improved the contact angle (CA) of the films up to 1.5 times. The TG-LEO films exhibited good transparency, higher elongation at break (EB), and lower Young's modulus (YM). Additionally, LEO positively affected the antioxidant and antimicrobial properties of the films. Overall, the results authenticated the hypothesis of this study and indicated that TG-LEO films have great potential as biodegradable films with promising functionalities for food packaging applications. [ABSTRACT FROM AUTHOR]

Plastic biodegradation has emerged as a sustainable approach and green alternative in handling the ever-increasing accumulation of plastic wastes in the environment. The complete biodegradation of polyethylene terephthalate is one of the most recent breakthroughs in the field of plastic biodegradation. Despite the success, the effective and complete biodegradation of a wide variety of plastics is still far from the practical implementation, and an on-going effort has been mainly devoted to the exploration of novel microorganisms and enzymes for plastic biodegradation. However, alternative strategies which enhance the existing biodegradation process should not be neglected in the continuous advancement of this field. Thus, this review highlights various strategies which have shown to improve the biodegradation of plastics, which include the pretreatment of plastics using UV irradiation, thermal, or chemical treatments to increase the susceptibility of plastics toward microbial action. Alternative pretreatment strategies are also suggested and compared with the existing techniques. Besides, the effects of additives such as pro-oxidants, natural polymers, and surfactants on plastic biodegradation are discussed. In addition, considerations governing the biodegradation performance, such as the formulation of biodegradation medium, cell-free biocatalysis, and physico-chemical properties of plastics, are addressed. Lastly, the challenges and future prospects for the advancement of plastic biodegradation are also highlighted. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrophobic ZIF-8/SA monolithic materials were fabricated via in situ synthesis. • The cooperation of SA, PDMS, and ZIF-8 significantly enhanced adsorption capacity. • The composites displayed rapid kinetic adsorption. • The composites have remarkable absorption recyclability. Microplastics (MPs), a newly emerging class of environmental contaminants, pose a severe threat to the entire ecosystem. The development of efficient and environmentally responsible adsorbents for removing the MPs is a particularly urgent research. Herein, a kind of monolithic ZIF-8 based adsorbents featuring stable hydrophobicity and micropore-mesopore-macropore hierarchical porous structure were fabricated by in situ growth of ZIF-8 nanoparticles on sodium alginate (SA) framework, and using polydimethylsiloxane (PDMS) as a hydrophobic agent. The monolithic nature of ZIF-8/SA allowed an easy solid–liquid separation process for adsorbents from water environment compared to powdered materials. The hierarchical porous structure ensures a remarkable MPs removal performance. The ZIF-8/SA showed high adsorption capacities of 594, 585, and 282 mg/g for polymethyl methacrylate (PMMA), poly (vinylidene difluoride) (PVDF), and polyvinyl chloride (PVC) respectively, and rapid adsorption kinetic progress within 120 min. The ZIF-8/SA adsorbents also exhibited excellent stability in the presence of interfering ions, acid/alkali, and humic acid, and displayed adsorption performance of > 70 % even in actual aquatic environment such as tap water, river water, and seawater. The results of characterizations showed that the synergistic effect of electrostatic interaction, hydrogen bonding, hydrophobic force, and van der Waals force was the main adsorption mechanism. The well-designed hydrophobic ZIF-8/SA monolithic materials would be promising to rapidly remove the MPs from the water environment. [ABSTRACT FROM AUTHOR]

• Interaction of plastic and scrap tyre during co-pyrolysis is plastic-specific. • Mixing PP or LDPE with tyre can promote aliphatic hydrocarbon and suppress PAHs. • Mixing PS with tyre can suppress PAHs and enhance MAs production, especially BTEX. • 75 wt% LDPE or PS with tyre at 600 °C yields sulphur-free pyrolytic oil. • Tyre char can promote cracking reactions in LDPE thermal degradation. Fast co-pyrolysis offers a sustainable solution for upcycling polymer waste, including scrap tyre and plastics. Previous studies primarily focused on slow heating rates, neglecting synergistic mechanisms and sulphur transformation in co-pyrolysis with tyre. This research explored fast co-pyrolysis of scrap tyre with polypropylene (PP), low-density polyethylene (LDPE), and polystyrene (PS) to understand synergistic effects and sulphur transformation mechanisms. A pronounced synergy was observed between scrap tyre and plastics, with the nature of the synergy being plastic-type dependent. Remarkably, blending 75 wt% PS or LDPE with tyre effectively eliminated sulphur-bearing compounds in the liquid product. This reduction in sulphur content can substantially mitigate the release of hazardous materials into the environment, emphasizing the environmental significance of co-pyrolysis. The synergy between PP or LDPE and tyre amplified the production of lighter hydrocarbons, while PS's interaction led to the creation of monocyclic aromatics. These findings offer insights into the intricate chemistry of scrap tyre and plastic interactions and highlight the potential of co-pyrolysis in waste management. By converting potential pollutants into valuable products, this method can significantly reduce the release of hazardous materials into the environment. [ABSTRACT FROM AUTHOR]

Ammonia, a vital component in the synthesis of fertilizers, plastics, and explosives, is traditionally produced via the energy‐intensive and environmentally detrimental Haber–Bosch process. Given its considerable energy consumption and significant greenhouse gas emissions, there is a growing shift toward electrocatalytic ammonia synthesis as an eco‐friendly alternative. However, developing efficient electrocatalysts capable of achieving high selectivity, Faraday efficiency, and yield under ambient conditions remains a significant challenge. This review delves into the decades‐long research into electrocatalytic ammonia synthesis, highlighting the evolution of fundamental principles, theoretical descriptors, and reaction mechanisms. An in‐depth analysis of the nitrogen reduction reaction (NRR) and nitrate reduction reaction (NitRR) is provided, with a focus on their electrocatalysts. Additionally, the theories behind electrocatalyst design for ammonia synthesis are examined, including the Gibbs free energy approach, Sabatier principle, d‐band center theory, and orbital spin states. The review culminates in a comprehensive overview of the current challenges and prospective future directions in electrocatalyst development for NRR and NitRR, paving the way for more sustainable methods of ammonia production. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the sustainable use of recycled plastics, specifically polypropylene (PP) and high-density polyethylene (HDPE), in the manufacture of geogrids for geotechnical and civil engineering applications. Plastics were collected from a recycling center, specifically targeting containers used for food, cleaning products, and other domestic packaging items. These plastics were sorted according to the Möbius triangle classification system, with HDPE (#2) and PP (#5) being the primary categories of interest. The research methodologically evaluates the mechanical properties of PP/HDPE (0/100, 25/75, 50/50, 75/25 and 100/0% w/w) composites through tensile and flexural tests, exploring various compositions and configurations of geogrids. The results highlight the superiority of pure recycled HDPE processed into 1.3 mm thick laminated yarns and hot air welded for 20 to 30 s, exhibiting a deformation exceeding 60% in comparison to the PP/HDPE composites. Through SolidWorks® Simulation, it was shown that the adoption of a trigonal geogrid geometry optimizes force distribution and tensile strength, significantly improving slope stabilization efficiency. Based on the results obtained, a laboratory-scale prototype geogrid was developed using an extrusion process. The results underscore the importance of careful composite design and yarn configuration selection to achieve the desired mechanical properties and performance in geogrid applications. It emphasizes the potential of recycled plastics as a viable and environmentally friendly solution for stabilizing slopes, contributing to the reduction in plastic waste and promoting sustainable construction practices. [ABSTRACT FROM AUTHOR]

Plastic pollution poses a significant environmental challenge, necessitating the investigation of bioplastics with reduced end-of-life impact. This study systematically characterizes four promising bioplastics—polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and polylactic acid (PLA). Through a comprehensive analysis of their chemical, thermal, and mechanical properties, we elucidate their structural intricacies, processing behaviors, and potential morphologies. Employing an environmentally friendly process utilizing supercritical carbon dioxide, we successfully produced porous materials with microcellular structures. PBAT, PBS, and PLA exhibit closed-cell morphologies, while PHBV presents open cells, reflecting their distinct overall properties. Notably, PBAT foam demonstrated an average porous area of 1030.86 μm2, PBS showed an average porous area of 673 μm2, PHBV displayed open pores with an average area of 116.6 μm2, and PLA exhibited an average porous area of 620 μm2. Despite the intricacies involved in correlating morphology with material properties, the observed variations in pore area sizes align with the findings from chemical, thermal, and mechanical characterization. This alignment enhances our understanding of the morphological characteristics of each sample. Therefore, here, we report an advancement and comprehensive research in bioplastics, offering deeper insights into their properties and potential morphologies with an easy sustainable foaming process. The alignment of the process with sustainability principles, coupled with the unique features of each polymer, positions them as environmentally conscious and versatile materials for a range of applications. [ABSTRACT FROM AUTHOR]

The increased use of plastics in industrial and agricultural applications has led to high levels of pollution worldwide and is a significant challenge. To address this plastic pollution, conventional methods such as landfills and incineration are used, leading to further challenges such as the generation of greenhouse gas emissions. Therefore, increasing interest has been directed to identifying alternative methods to dispose of plastic waste from agriculture. The novelty of the current research arose from the lack of critical reviews on how 3-Dimensional (3D) printing was adopted for recycling plastics, its application in the production of agricultural plastics, and its specific benefits, disadvantages, and limitations in recycling plastics. The review paper offers novel insights regarding the application of 3D printing methods including Fused Particle Fabrication (FPF), Hot Melt Extrusion (HME), and Fused Deposition Modelling (FDM) to make filaments from plastics. However, the methods were adopted in local recycling setups where only small quantities of the raw materials were considered. Data was collected using a systematic review involving 39 studies. Findings showed that the application of the 3D printing methods led to the generation of agricultural plastics such as Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate (PET), and High-Density Polyethylene (HDPE), which were found to have properties comparable to those of virgin plastic, suggesting the viability of 3D printing in managing plastic pollution. However, limitations were also associated with the 3D printing methods; 3D-printed plastics deteriorated rapidly under Ultraviolet (UV) light and are non-biodegradable, posing further risks of plastic pollution. However, UV stabilization helps reduce plastic deterioration, thus increasing longevity and reducing disposal. Future directions emphasize identifying methods to reduce the deterioration of 3D-printed agricultural plastics and increasing their longevity in addition to UV stability. [ABSTRACT FROM AUTHOR]

Polymeric materials undergo degradation when exposed to outdoor conditions due to the synergistic effects of sunlight, air, heat, and moisture. The degradation can lead to a decline in mechanical properties, fading, surface cracking, and haziness, attributed to the cleavage of the polymer chains and oxidation reactions. Accelerated weathering testing is a useful technique to evaluate the comparative photodegradation of materials within a reasonable timeframe. This review gives an overview of the different degradation mechanisms occurring in conventional plastics and bio-based materials. Case studies on accelerated weathering and its effect on the mechanical properties of conventional plastics and biocomposites are discussed. Different techniques for analysing volatile organic emissions (VOCs) have been summarized and studies highlighting the characterization of VOCs from aged plastics and biocomposites after aging have been cited. [ABSTRACT FROM AUTHOR]

Plastic containers, commonly produced from non-biodegradable petroleum-based plastics such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET), raise significant environmental concerns due to their persistence. The disposal of agricultural waste, specifically rice straw (RS), through burning, further compounds these environmental issues. In response, this study explores the integration of polylactic acid (PLA), a biodegradable material, with RS using a twin-screw extruder and injection process, resulting in the creation of a biodegradable packaging material. The inclusion of RS led to a decrease in the melt flow rate, thermal stability, and tensile strength, while concurrently enhancing the hydrophilic properties of the composite polymers. Additionally, the incorporation of maleic anhydride (MA) contributed to a reduction in the water absorption rate. The optimized formulation underwent migration testing and met the standards for food packaging products. Furthermore, no MA migration was detected from the composite. This approach not only provides a practical solution for the disposal of RS, but also serves as an environmentally-friendly alternative to conventional synthetic plastic waste. [ABSTRACT FROM AUTHOR]

Non-degradable plastics of petrochemical origin are a contemporary problem of society. Due to the large amount of plastic waste, there are problems with their disposal or storage, where the most common types of plastic waste are disposable tableware, bags, packaging, bottles, and containers, and not all of them can be recycled. Due to growing ecological awareness, interest in the topics of biodegradable materials suitable for disposable items has begun to reduce the consumption of non-degradable plastics. An example of such materials are biodegradable biopolymers and their derivatives, which can be used to create the so-called bioplastics and biopolymer blends. In this article, gelatine blends modified with polysaccharides (e.g., agarose or carrageenan) were created and tested in order to obtain a stable biopolymer coating. Various techniques were used to characterize the resulting bioplastics, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)/differential scanning calorimetry (DSC), contact angle measurements, and surface energy characterization. The influence of thermal and microbiological degradation on the properties of the blends was also investigated. From the analysis, it can be observed that the addition of agarose increased the hardness of the mixture by 27% compared to the control sample without the addition of polysaccharides. In addition, there was an increase in the surface energy (24%), softening point (15%), and glass transition temperature (14%) compared to the control sample. The addition of starch to the gelatine matrix increased the softening point by 15% and the glass transition temperature by 6%. After aging, both compounds showed an increase in hardness of 26% and a decrease in tensile strength of 60%. This offers an opportunity as application materials in the form of biopolymer coatings, dietary supplements, skin care products, short-term and single-contact decorative elements, food, medical, floriculture, and decorative industries. [ABSTRACT FROM AUTHOR]

Pistachio (Pistacia vera L.) is consumed in almost every part of the world enclosed in shells that are thrown out in baskets. Similarly, hulls separated from pistachio are discarded as waste in food processing industries. These waste materials contain functional constituents having immense industrial and nutraceutical applications. This review article summarizes the scientific investigations regarding the functional constituents and bioactive compounds in pistachio shells (PSs) and pistachio hulls (PHs). It also highlights the nutraceutical potential exhibited by functionally active compounds as well as their potential applications in various industries including nutraceutical, medicinal, and feed industries together with biosynthetic development of useful products and wastewater treatment. Pistachio waste (PW) comprising PS and PH is a rich source of various bioactive compounds. PS is full of lignin, cellulose, and hemicellulose. PH is an excellent source of carbohydrates (80.64 ± 0.98%) (including glucose, galactose, rhamnose, arabinose, xylose, mannose, galacturonic acid) as well as ash (6.32 ± 0.26%) and proteins (1.80 ± 0.28%) with small amounts of fats (0.04 ± 0.005%). Owing to its composition, PW can be beneficial in many nutraceuticals, including antioxidation, cytoprotection, anti-obesity, anti-diabetic, anti-melanogenesis, neuroprotection, anti-cancer, anti-mutagenesis, anti-inflammation, and anti-microbial. The waste materials have vast applications in the food industry, such as bio-preservation of oils and meat products, prevention of enzymatic browning in fruits, vegetables, and mushrooms, development of functional cereal and dairy products, production of food enzymes, emulsions, and manufacturing of biodegradable films for food packaging. The use of these waste products to develop and design novel functional foods with improved quality is important for both food industries and food sustainability. [ABSTRACT FROM AUTHOR]

The root cause of global pollution is the reflection of usage of non-degradable plastics. The solutions and methods to mitigate the plastic pollution are in high demand. The application of green technology in polymer science from the marine resource gives stability to the ecosystem. The bio-composite films were fabricated using gelatin of fish scale, agar of seaweed and chitosan of shrimp shell waste by a solvent casting technique. The plasticity and bioactivity enhanced using glycerol and clove essential oil. The physic-chemical and mechanical properties of the film were evaluated against the range of test of thickness, tensile strength, elongation at break, puncture resistance, water vapor permeability, Attenuated Total Reflection—Fourier Transform Infrared spectroscopy, X-ray diffraction and atomic force microscopy. The characteristics of active packaging mechanism assessed based on antimicrobial and antioxidative properties. A level of 1.5% clove essential oil ration was given desirable properties of active packaging material. The biodegradability was calculated in terms of percentage weight loss under the soil burial and water immersion test. The biodegradation process of composite film took 21 days in soil and 158 in water. Hence, the bio-composite film prepared from green technology is a promising alternative to the conventional plastic to mitigate plastic pollution. [ABSTRACT FROM AUTHOR]

Functional antibacterial textile materials are in great demand in the medical sector. In this paper, we propose a facile, eco-friendly approach to the design of antibacterial biodegradable cotton fabrics. Cotton fiber fabrics were enhanced with a chitosan coating loaded with plant extracts and essential oils. We employed Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), UV–Vis spectrophotometry, optical microscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to characterize the color, structure, and thermal properties of the modified fabrics. The fabrics were found to effectively induce growth inhibition of Gram-positive and Gram-negative bacteria, especially when a synergic system of aloe vera extract and cinnamon essential oil was applied in the coating formulation. Additionally, we observed significant color and weight changes after 5, 10, and 20 days in soil biodegradability tests. Given the straightforward modification process and the use of non-toxic natural materials, these innovative bio-based and biodegradable cotton fabrics show great promise as protective antimicrobial textiles for healthcare applications. [ABSTRACT FROM AUTHOR]

Developing dynamic chemistry for polymeric materials offers chemical solutions to solve key problems associated with current plastics. Mechanical performance and dynamic function are equally important in material design because the former determines the application scope and the latter enables chemical recycling and hence sustainability. However, it is a long‐term challenge to balance the subtle trade‐off between mechanical robustness and dynamic properties in a single material. The rise of dynamic chemistry, including supramolecular and dynamic covalent chemistry, provides many opportunities and versatile molecular tools for designing constitutionally dynamic materials that can adapt, repair, and recycle. Facing the growing social need for developing advanced sustainable materials without compromising properties, recent progress showing how the toolbox of dynamic chemistry can be explored to enable high‐performance sustainable materials by molecular engineering strategies is discussed here. The state of the art and recent milestones are summarized and discussed, followed by an outlook toward future opportunities and challenges present in this field. [ABSTRACT FROM AUTHOR]

Plastic accumulation is a severe threat to the environment due to its resistivity to thermal, mechanical and biological processes. In recent years, microbial degradation of plastic waste disposal is of interest because of its eco-friendly nature. In this study, a total of 33 fungi were isolated from the plastisphere and out of which 28 fungal species showed halo zone of clearance in agarized LDPE media. The fungus showing highest zone of clearance was further used to evaluate its degradation potential. Based on morphological and molecular technique, the fungus was identified as Cladosporium sphaerospermum. The biodegradation of LDPE by C. sphaerospermum was evaluated by various methods. The exposure of LDPE with C. sphaerospermum resulted in weight loss (15.23%) in seven days, higher reduction rate (0.0224/day) and lower half-life (30.93 days). FTIR analysis showed changes in functional group and increased carbonyl index in LDPE treated with C. sphaerospermum. SEMimages evidenced the formation of pits, surface aberrations and grooves on the LDPE film treated with the fungus whereas the untreated control LDPE film showed no change. AFM analysis confirmed the surface changes and roughness in fungus treated LDPE film. This might be due to the extracellular lignolytic enzymes secreted by C. sphaerospermum grown on LDPE. The degradation of polyethylene by Short chain alkanes such as dodecane, hexasiloxane and silane were identified in the extract of fungus incubated with LDPE film through GC–MS analysis which might be due to the degradation of LDPE film by C. sphaerospermum. This was the first report on the LDPE degradation by C. sphaerospermum in very short duration which enables green scavenging of plastic wastes. [ABSTRACT FROM AUTHOR]

Biodegradable plastics, represented by polylactic acid (PLA), are considered suitable alternatives to nondegradable commodity plastics; however, their degradation through microbial decomposition is seen as a waste of carbon resources and inevitably brings about CO2 emission. Alternatively, waste PLA plastics can be utilized as feedstocks for the sustainable production of value-added chemicals, which not only avoids a carbon footprint but also realizes upcycling of plastic waste. Here, we show a cascade system that combines alkali-induced depolymerization, pulsed electrooxidation, and electrochemical reductive amination to produce alanine with an overall yield of 69% under near ambient conditions. Specifically, we first implement an alkali catalyst in an aqueous solution to depolymerize PLA into lactate. The obtained PLA hydrolysate is directly utilized as both feedstock and electrolyte for pyruvate production over a nickel hydroxide-supported Pd electrocatalyst (Pd/Ni(OH)2) via a pulsed potential, which is followed by the transformation of pyruvate into alanine using a TiO2 catalyst. This cascade process for alanine production benefits from high efficiencies maintained in three consecutive processes, mild operation conditions, and the use of cost-effective feedstocks (plastic wastes), without suffering harsh conditions and expensive feedstock consumption required by conventional biological and chemical approaches for alanine synthesis, respectively. [ABSTRACT FROM AUTHOR]

To reduce global CO2 emissions in line with EU targets, it is essential that we replace fossil-derived plastics with renewable alternatives. This provides an opportunity to develop novel plastics with improved design features, such as better reusability, recyclability, and environmental biodegradability. Although recycling and reuse of plastics is favoured, this relies heavily on the infrastructure of waste management, which is not consistently advanced on a worldwide scale. Furthermore, today's bulk polyolefin plastics are inherently unsuitable for closed-loop recycling, but the introduction of plastics with enhanced biodegradability could help to combat issues with plastic accumulation, especially for packaging applications. It is also important to recognise that plastics enter the environment through littering, even where the best waste-collection infrastructure is in place. This causes endless environmental accumulation when the plastics are non-(bio)degradable. Biodegradability depends heavily on circumstances; some biodegradable polymers degrade rapidly under tropical conditions in soil, but they may not also degrade at the bottom of the sea. Biodegradable polyesters are theoretically recyclable, and even if mechanical recycling is difficult, they can be broken down to their monomers by hydrolysis for subsequent purification and re-polymerisation. Additionally, both the physical properties and the biodegradability of polyesters are tuneable by varying their building blocks. The relationship between the (chemical) structures/compositions (aromatic, branched, linear, polar/apolar monomers; monomer chain length) and biodegradation/hydrolysis of polyesters is discussed here in the context of the design of biodegradable polyesters. [ABSTRACT FROM AUTHOR]

Plastic materials, including microplastics, accumulate in all types of ecosystems, even in remote and cold environments such as the European Alps. This pollution poses a risk for the environment and humans and needs to be addressed. Using shotgun DNA metagenomics of soils collected in the eastern Swiss Alps at about 3,000 m a.s.l., we identified genes and their proteins that potentially can degrade plastics. We screened the metagenomes of the plastisphere and the bulk soil with a differential abundance analysis, conducted similarity-based screening with specific databases dedicated to putative plastic-degrading genes, and selected those genes with a high probability of signal peptides for extracellular export and a high confidence for functional domains. This procedure resulted in a final list of nine candidate genes. The lengths of the predicted proteins were between 425 and 845 amino acids, and the predicted genera producing these proteins belonged mainly to Caballeronia and Bradyrhizobium. We applied functional validation, using heterologous expression followed by enzymatic assays of the supernatant. Five of the nine proteins tested showed significantly increased activities when we used an esterase assay, and one of these five proteins from candidate genes, a hydrolase-type esterase, clearly had the highest activity, by more than double. We performed the fluorescence assays for plastic degradation of the plastic types BI-OPL and ecovio® only with proteins from the five candidate genes that were positively active in the esterase assay, but like the negative controls, these did not show any significantly increased activity. In contrast, the activity of the positive control, which contained a PLA-degrading gene insert known from the literature, was more than 20 times higher than that of the negative controls. These findings suggest that in silico screening followed by functional validation is suitable for finding new plastic-degrading enzymes. Although we only found one new esterase enzyme, our approach has the potential to be applied to any type of soil and to plastics in various ecosystems to search rapidly and efficiently for new plastic-degrading enzymes. [ABSTRACT FROM AUTHOR]

Zinc (Zn)–dysprosium (Dy) binary alloys are promising biodegradable bone fracture fixation implants owing to their attractive biodegradability and mechanical properties. However, their clinical application is a challenge for bone fracture healing, due to the lack of Zn–Dy alloys with tailored proper bio‐mechanical and osteointegration properties for bone regeneration. A Zn‐5Dy alloy with high strength and ductility and a degradation rate aligned with the bone remodeling cycle is developed. Here, mechanical stability is further confirmed, proving that Zn‐5Dy alloy can resist aging in the degradation process, thus meeting the mechanical requirements of fracture fixation. In vitro cellular experiments reveal that the Zn‐5Dy alloy enhances osteogenesis and angiogenesis by elevating SIRT4‐mediated mitochondrial function. In vivo Micro‐CT, SEM‐EDS, and immunohistochemistry analyses further indicate good biosafety, suitable biodegradation rate, and great osteointegration of Zn‐5Dy alloy during bone healing, which also depends on the upregulation of SIRT4‐mediated mitochondrial events. Overall, the study is the first to report a Zn‐5Dy alloy that exerts remarkable osteointegration properties and has a strong potential to promote bone healing. Furthermore, the results highlight the importance of mitochondrial modulation and shall guide the future development of mitochondria‐targeting materials in enhancing bone fracture healing. [ABSTRACT FROM AUTHOR]

Plastic degradation by biological systems emerges as a prospective avenue for addressing the pressing global concern of plastic waste accumulation. The intricate chemical compositions and diverse structural facets inherent to polyurethanes (PU) substantially increase the complexity associated with PU waste management. Despite the extensive research endeavors spanning over decades, most known enzymes exhibit a propensity for hydrolyzing waterborne PU dispersion (i.e., the commercial Impranil DLN-SD), with only a limited capacity for the degradation of bulky PU materials. Here, we report a novel cutinase (CpCut1) derived from Cladosporium sp. P7, which demonstrates remarkable efficiency in the degrading of various polyester-PU materials. After 12-h incubation at 55°C, CpCut1 was capable of degrading 40.5% and 20.6% of thermoplastic PU film and post-consumer foam, respectively, while achieving complete depolymerization of Impranil DLN-SD. Further analysis of the degradation intermediates suggested that the activity of CpCut1 primarily targeted the ester bonds within the PU soft segments. The versatile performance of CpCut1 against a spectrum of polyester-PU materials positions it as a promising candidate for the bio-recycling of waste plastics. IMPORTANCE Polyurethane (PU) has a complex chemical composition that frequently incorporates a variety of additives, which poses significant obstacles to biodegradability and recyclability. Recent advances have unveiled microbial degradation and enzymatic depolymerization as promising waste PU disposal strategies. In this study, we ident ified a gene encoding a cutinase from the PU-degrading fungus Cladosporium sp. P7, which allowed the expression, purification, and characterization of the recombinant enzyme CpCut1. Furthermore, this study identified the products derived from the CpCut1 catalyzed PU degradation and proposed its underlying mechanism. These findings highlight the potential of this newly discovered fungal cutinase as a remarkably efficient tool in the degradation of PU materials. [ABSTRACT FROM AUTHOR]

Cellulose is the most attractive renewable natural polymer, carrying off a 211 billion USD market size that entered the plastic world for industrial application. However, the extraction of cellulose forms (micro/nano) in an economical manner is still challenging for researchers who have been trying different cellulose-based sources and methods. Henceforth, the present study focused on extracting cellulose microfibers (CMFs) from agro biomass to mitigate the cost of satisfying industrial demands. The waste fallen dried leaves were used to extract micro cellulose through alkaline peroxide treatment and studied the essential characteristics like morphology, spectral and crystallinity, and CMFs having 45.8 µm size with rough morphology and the spectral peak of 3339 cm−1, and 2890 cm−1 corresponding to hydrogen bond O–H, and C–H of cellulose respectively. Further, the various % (5–15) of CMFs were reinforced to polyvinyl alcohol (PVA) to prepare CMFs/PVA composites through the solution casting method. The experimental results showed that the composites having chemical interaction bond at 3260 cm−1 and 2θ = 19.6◦ diffraction peak. The optimized % of CMFs showing tensile strength 80.37 MPa and 2.51 GPa and decreased 9.37% elongation at break. CMFs loading significantly enhanced biodegradation by about 21.44%. This improvement in biodegradation highlights the potential environmental benefits of utilizing CMFs in plastic film production. In conclusion, this study provides the idea of economically obtaining micro cellulose and designing biodegradable plastic for packaging application. [ABSTRACT FROM AUTHOR]

This article explores the relationship between solar UV radiation, climate change, and plastic pollution. It highlights the role of UV-driven weathering in the degradation of plastics and the formation of harmful micro- and nanoplastic particles. The article emphasizes the need for global assessments of plastic dispersal, persistence, and weathering to consider these linkages. It also discusses the impact of the Montreal Protocol on plastic degradation and the potential effects of UV radiation and climate change on plastic pollution in the future. The article concludes by calling for further research and the development of new plastics with durability matching the functional life of products. [Extracted from the article]

Bioplastics, comprised of bio‐based and/or biodegradable polymers, have the potential to play a crucial role in the transition towards a sustainable circular economy. The use of biodegradable polymers not only leads to reduced greenhouse gas emissions but also might address the problem of plastic waste persisting in the environment, especially when removal is challenging. Nevertheless, biodegradable plastics should not be considered as substitutes for proper waste management practices, given that their biodegradability strongly depends on environmental conditions. Among the challenges hindering the sustainable implementation of bioplastics in the market, the development of effective downstream recycling routes is imperative, given the increasing production volumes of these materials. Here, we discuss about the most advisable end‐of‐life scenarios for bioplastics. Various recycling strategies, including mechanical, chemical or biological (both enzymatic and microbial) approaches, should be considered. Employing enzymes as biocatalysts emerges as a more selective and environmentally friendly alternative to chemical recycling, allowing the production of new bioplastics and added value and high‐quality products. Other pending concerns for industrial implementation of bioplastics include misinformation among end users, the lack of a standardised bioplastic labelling, unclear life cycle assessment guidelines and the need for higher financial investments. Although further research and development efforts are essential to foster the sustainable and widespread application of bioplastics, significant strides have already been made in this direction. [ABSTRACT FROM AUTHOR]

Plastics are versatile materials that have the potential to propel humanity towards circularity and ultimate societal sustainability. However, the escalating concern surrounding plastic pollution has garnered significant attention, leading to widespread negative perceptions of these materials. Here, we question the role microbes may play in plastic pollution bioremediation by (i) defining polymer biodegradability (i.e., recalcitrant, hydrolysable and biodegradable polymers) and (ii) reviewing best practices for evaluating microbial biodegradation of plastics. We establish recommendations to facilitate the implementation of rigorous methodologies in future studies on plastic biodegradation, aiming to push this field towards the use of isotopic labelling to confirm plastic biodegradation and further determine the molecular mechanisms involved. [ABSTRACT FROM AUTHOR]

Mineral plastics are a promising class of bio‐inspired materials that offer exceptional properties, like self‐heal ability, stretchability in the hydrogel state, and high hardness, toughness, transparency, and non‐flammability in the dry state along with reversible transformation into the hydrogel by addition of water. This enables easy reshape‐ability and recycling like the solubility in mild acids to subsequently form mineral plastics again by base addition. However, current mineral plastics rely on petrochemistry, are hardly biodegradable, and thus persistent in nature. This work presents the next generation of mineral plastics, which are bio‐based and biodegradable, making them a promising, new class of polymers for the development of environmentally friendly materials. Physically cross‐linked (poly)glutamic‐acid (PGlu)‐based mineral plastics are synthesized using various alcohol‐water mixtures, metal ion ratios and molecular weights. The rheological properties are easily adjusted using these parameters. The general procedure involves addition of equimolar solution of CaCl2 to PGlu in equal volumes followed by addition of iPrOH (iPrOH:H2O = 1:1) under vigorous stirring conditions. The ready biodegradability of PGlu/CaFe mineral plastic is confirmed in this study where the elements N, Ca, and Fe present in it tend to act as additional nutrients, supporting the growth of microorganisms and consequently, promoting the biodegradation process. [ABSTRACT FROM AUTHOR]

Within the scope of the current study, the researchers developed activities for middle school students to raise their awareness on the harm of plastics and microplastics, which are detrimental to nature and living things. In addition, through the activities developed, the study aimed to provide students with knowledge of and experience with bioplastics, which have emerged as an alternative to plastic materials and are environmentally friendly. Twelve eighth grade students participated in the current study. The activities developed by the researchers within the framework of the REACT strategy covered a four-week period. The researchers made sure that the activities designed included each step of the REACT strategy (Relating, Experiencing, Applying, Cooperating, Transferring) and the researchers used different tools (mind map, concept map, Vee diagram). The study suggests that activities designed for classroom use should be integrated with tools such as Vee diagram, concept map and mind map in order to increase students' knowledge and awareness about global environmental problems as well as support students' ability to produce solutions to such problems. [ABSTRACT FROM AUTHOR]

Understanding and characterizing semi-crystalline models with crystalline and amorphous segments is crucial for industrial applications. A coarse-grained molecular dynamics (CGMD) simulations study probed the crystal network formation in high-density polyethylene (HDPE) from melt, and shed light on tensile properties for microstructure analysis. Modified Paul–Yoon–Smith (PYS/R) forcefield parameters are used to compute the interatomic forces among the PE chains. The isothermal crystallization at 300 K and 1 atm predicts the multi-nucleus crystal growth; moreover, the lamellar crystal stems and amorphous region are alternatively oriented. A one-dimensional density distribution along the alternative lamellar stems further confirms the ordering of the lamellar-stack orientation. Using this plastic model preparation approach, the semi-crystalline model density ( ρ c r ) of ca. 0.913 g·cm−3 and amorphous model density ( ρ a m ) of ca. 0.856 g·cm−3 are obtained. Furthermore, the ratio of ρ c r / ρ a m ≈ 1.06 is in good agreement with computational (≈1.096) and experimental (≈1.14) data, ensuring the reliability of the simulations. The degree of crystallinity ( χ c ) of the model is ca. 52% at 300 K. Nevertheless, there is a gradual increase in crystallinity over the specified time, indicating the alignment of the lamellar stems during crystallization. The characteristic stress–strain curve mimicking tensile tests along the z-axis orientation exhibits a reversible sharp elastic regime, tensile strength at yield ca. 100 MPa, and a non-reversible tensile strength at break of 350%. The cavitation mechanism embraces the alignment of lamellar stems along the deformation axis. The study highlights an explanatory model of crystal network formation for the PE model using a PYS/R forcefield, and it produces a microstructure with ordered lamellar and amorphous segments with robust mechanical properties, which aids in predicting the microstructure–mechanical property relationships in plastics under applied forces. [ABSTRACT FROM AUTHOR]

Polyethylene-, polyvinylidene chloride-, and per- and polyfluoroalkyl substance-coated paper generate microplastics or fluorochemicals in the environment. Here, we report an approach for the development of oil-resistant papers using an environmentally friendly, fluorine-free, water-dispersible poly(dimethylsiloxane) (PDMS) coating on kraft paper. Carboxylic-functionalized PDMS (PDMS-COOH) was synthesized and subsequently neutralized with ammonium bicarbonate to obtain a waterborne emulsion, which was then coated onto kraft paper. The water resistance of the coated paper was determined via Cobb60 measurements. The Cobb60 value was reduced to 2.70 ± 0.14 g/m2 as compared to 87.6 ± 5.1 g/m2 for uncoated paper, suggesting a remarkable improvement in water resistance. Similarly, oil resistance was found to be 12/12 on the kit test scale versus 0/12 for uncoated paper. In addition, the coated paper retained 70–90% of its inherent mechanical properties, and more importantly, the coated paper was recycled via pulp recovery using a standard protocol with a 91.1% yield. [ABSTRACT FROM AUTHOR]

Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) shows promise for use in bioplastic applications due to its greater flexibility over PLLA. However, further research is needed to improve PLLA-PEG-PLLA's properties with appropriate fillers. This study employed zinc phenylphosphate (PPZn) as a multi-functional filler for PLLA-PEG-PLLA. The effects of PPZn addition on PLLA-PEG-PLLA characteristics, such as crystallization and thermal and mechanical properties, were investigated. There was good phase compatibility between the PPZn and PLLA-PEG-PLLA. The addition of PPZn improved PLLA-PEG-PLLA's crystallization properties, as evidenced by the disappearance of the cold crystallization temperature, an increase in the crystallinity, an increase in the crystallization temperature, and a decrease in the crystallization half-time. The PLLA-PEG-PLLA's thermal stability and heat resistance were enhanced by the addition of PPZn. The PPZn addition also enhanced the mechanical properties of the PLLA-PEG-PLLA, as demonstrated by the rise in ultimate tensile stress and Young's modulus. We can conclude that the PPZn has potential for use as a multi-functional filler for the PLLA-PEG-PLLA composite due to its nucleating-enhancing, thermal-stabilizing, and reinforcing ability. [ABSTRACT FROM AUTHOR]

Due to the extensive application of petroleum-based plastics as packaging materials and problems related to their degradation/recycling, developing new solutions in the field of novel biopolymer-based materials has become imperative. Natural substitutes for synthetic polymers (starch, cellulose, chitosan) require modifications that enable their processing and provide them with additional properties (i.e., mechanical strength, controlled biodeterioration, antimicrobial and antioxidative activity). The antioxidant activity of natural packaging materials still requires further investigation. In this research paper, novel materials used for packaging perishable food susceptible to oxidizing agents were designed from potato starch (NS) reinforced with antioxidants such as dialdehyde starch (DS) and caffeic acid (CA)/quinic acid (QA). The use of spectroscopic techniques (ATR-FTIR, Raman) and X-ray diffraction allowed the examination of the chemical structure and arrangement of the blend and confirmed the component interactions. The film surface was examined by AFM. DS, functioning as a cross-linker, enhanced the film barrier as well as the mechanical and thermal properties, and it promoted starch amorphization when blended with other antioxidants. The antioxidant activity of caffeic acid was greater than that of quinic acid. Dialdehyde starch improves elasticity, whereas acids (particularly caffeic acid) influence film stiffness. A high susceptibility to biodegradation is valuable for potential eco-friendly packaging applications. [ABSTRACT FROM AUTHOR]

Though paper is an environmentally friendly alternative to plastic as a packaging material, it lacks antibacterial properties, and some papers have a low resistance to oil or water. In this study, a multifunctional paper-coating material was developed to reduce the use of plastic packaging and enhance paper performance. Natural cellulose nanocrystals (CNCs) with excellent properties were used as the base material for the coating. The CNCs were functionalized into dialdehyde CNCs (DACNCs) through periodate oxidation. The DACNCs were subsequently complexed using erythrosine as a photosensitizer to form an erythrosine–CNC composite (Ery-DACNCs) with photodynamic inactivation. The Ery-DACNCs achieved inactivations above 90% after 30 min of green light irradiation and above 85% after 60 min of white light irradiation (to simulate real-world lighting conditions), indicating photodynamic inactivation effects. The optimal parameters for a layer-by-layer dip coating of kraft paper with Ery-DACNCs were 4.5-wt% Ery-DACNCs and 15 coating layers. Compared to non-coated kraft paper and polyethylene-coated paper, the Ery-DACNC-coated paper exhibited enhanced mechanical properties (an increase of 28% in bursting strength). More than 90% of the bacteria were inactivated after 40 min of green light irradiation, and more than 80% were inactivated after 60 min of white light irradiation. [ABSTRACT FROM AUTHOR]

Biocomposites were fabricated utilizing polylactic acid (PLA) combined with native starch sourced from mountain's yam (Dioscorea remotiflora Knuth), an underexplored tuber variety. Different starch compositions (7.5, 15.0, 22.5, and 30.0 wt.%) were blended with PLA in a batch mixer at 160 °C to produce PLA/starch biocomposites. The biocomposites were characterized by analyzing their morphology, particle size distribution, thermal, X-ray diffraction (XDR), mechanical, and dynamic mechanical (DMA) properties, water absorption behavior, and color. The results showed that the amylose content of Dioscorea remotiflora starch was 48.43 ± 1.4%, which corresponds to a high-amylose starch (>30% of amylose). Particle size analysis showed large z-average particle diameters (Dz0) of the starch granules (30.59 ± 3.44 μm). Scanning electron microscopy (SEM) images showed oval-shaped granules evenly distributed throughout the structure of the biocomposite, without observable agglomeration or damage to its structure. XDR and DMA analyses revealed an increase in the crystallinity of the biocomposites as the proportion of the starch increased. The tensile modulus (E) underwent a reduction, whereas the flexural modulus (Eflex) increased with the amount of starch incorporated. The biocomposites with the highest Eflex were those with a starch content of 22.5 wt.%, which increased by 8.7% compared to the neat PLA. The water absorption of the biocomposites demonstrated a higher uptake capacity as the starch content increased. The rate of water absorption in the biocomposites followed the principles of Fick's Law. The novelty of this work lies in its offering an alternative for the use of high-amylose mountain's yam starch to produce low-cost bioplastics for different applications. [ABSTRACT FROM AUTHOR]

Microplastics have garnered an infamous reputation as a sorbate for many concerning environmental pollutants and as a delivery vehicle for the aquatic food chain through the ingestion of these contaminated small particulates. While sorption mechanisms have been extensively studied for polycyclic aromatic hydrocarbons, polycyclic aromatic sulfur heterocycles (PASHs) have not been investigated, partly due to their low concentrations in aquatic ecosystems. Herein, an analytical methodology is presented for the analysis of dibenzothiophene, benzo[b]naphtho[1,2-b]thiophene, benzo[b]naphtho[2,1-b]thiophene, benzo[b]naphtho[2,3-b]thiophene, chryseno[4,5-bcd]thiophene and dinaphtho[1,2-b:1′,2′-d]thiophene at relevant environmental concentrations based on solid phase extraction and high-performance liquid chromatography. The sorption uptake behavior and the sorption kinetics of the three benzo[b]napthothiophene isomers were then investigated on nylon microplastics to provide original information on their environmental fate and avoid human contamination through the food chain. The obtained information might also prove relevant to the development of successful remediation approaches for aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Frequently used protective items during the pandemics are prepared from plastics products, such as polypropylene, polyurethane, polyacrylonitrile, polystyrene, polycarbonate, polyethylene, and polyester. Globally more than 57 million pounds of personal protective equipment along with other biomedical plastic waste are entering into the oceans per annum. Lots of economic benefits can be obtained by recycling the polymeric wastes by converting them into useful products through, reduced manufacture cost, bio converted products, and cleaner environment by developing a circular waste management model. Personal protective equipment's are prepared from different plastic products and the outer most surface of these free-floating plastics presents in the aquatic environment serve as colonization support to diverse microbial populations known as plastisphere. Microbial colonization starts with an initial attachment under different environmental conditions, subsequently by developing a permanent association on the plastic surface. The community structure of microorganisms in the plastisphere can be significantly influenced by the depth of water in the aquatic ecosystem where microplastics present and the nutrients availability. As microorganisms have been deeply investigated for their role in the biodegradation of several pollutants, the present review article focuses on microbial diversity on plastisphere in the aquatic ecosystem, the underlying mechanism of colonization, and their potential role in microplastic degradation. This review article also highlights on imminent research for sustainable management of aquatic microplastic pollution. [ABSTRACT FROM AUTHOR]

The quest to reduce global plastic consumption has led to the emergence of biodegradable fiber-based composites as a promising sustainable replacement to conventional plastics in the food packaging industry. As the packaging sector is shifting more towards fiber-centric materials, thermoforming techniques for the 3D forming of the fiber-based materials, especially using complex mold designs, should be thoroughly researched to replace the conventional plastics in the industry. Finite element analysis of the deformation behavior of the paperboard during the thermoforming process and the factors that trigger the fracture of the composite layers were studied in the present work. The results show that 90° fiber orientation, 0.3 mm sheet thicknesses, and specific mold geometries can result in better forming results, thereby maximizing the potential of fiberbased materials in thermoforming. [ABSTRACT FROM AUTHOR]

There are several physical and chemical methods for synthesizing nanomaterials, while the most appropriate techniques involve using green chemistry and eco-friendly material. Recently, green synthesized materials for different applications have gained attention as a result of their environmental friendliness and cost-effectiveness. Applying green synthesized nanoparticles (NPS) in food packaging has been extensively investigated. Biopolymers require filler to enhance the optical, barrier, thermal, antimicrobial, and mechanical properties of packaging. Biopolymer packaging incorporated with green synthesized NPs is expected to simultaneously enhance performance while reducing environmental damage. The current review article focuses on biopolymer films with bio (green)-synthesized nanomaterials and their effectiveness in reducing the negative environmental implications of synthetic packaging. It also covers the general concepts of green synthesis of NPs, their production methods, their performance, and characterization, and discusses the potential, performance and recent developments of bio-nanocomposite films/coatings in biodegradable food packaging. Recent reports and trends provide more insight into the impact of green synthesized nanomaterials on food packaging. [ABSTRACT FROM AUTHOR]

Screw extruders as continuous flow reactors allow the synthesis of new polymers, preparation of polymer blends and composites, and modification or functionalization of commercially available polymers. Literature data shows that the twin screw extrusion is the most popular solution used for this purpose. In contrast, the number of scientific papers on alternative methods, such as multi-screw extruders, is somewhat limited. This paper is the first review of the application of planetary roller extruders in the compounding and reactive processing of polymer blends and composites. To fill current knowledge gaps, we discuss the advantages and disadvantages of planetary roller extruders compared to other screw extruders. Moreover, we summarize recent advances in planetary roller extrusion in producing thermal sensitive and biodegradable polymeric materials, rubber compounds, materials for 3D printing, or plastics and rubber recycling. This work also proposes the possible scenarios for further sustainable development of polymer blends and composites using planetary roller extruders. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET), the most abundantly produced polyester plastic, can be depolymerized by the Ideonella sakaiensis PETase enzyme. Based on multiple PETase crystal structures, the reaction has been proposed to proceed via a two-step serine hydrolase mechanism mediated by a serine-histidine-aspartate catalytic triad. To elucidate the multi-step PETase catalytic mechanism, we use transition path sampling and likelihood maximization to identify optimal reaction coordinates for the PETase enzyme. We predict that deacylation is likely rate-limiting, and the reaction coordinates for both steps include elements describing nucleophilic attack, ester bond cleavage, and the "moving-histidine" mechanism. We find that the flexibility of Trp185 promotes the reaction, providing an explanation for decreased activity observed in mutations that restrict Trp185 motion. Overall, this study uses unbiased computational approaches to reveal the detailed reaction mechanism necessary for further engineering of an important class of enzymes for plastics bioconversion. Polyethylene terephthalate (PET) can be depolymerized by the Ideonella sakaiensis PETase enzyme, however, questions remain about the precise catalytic mechanism. Here, the authors use unbiased QM/MM MD simulations to determine optimal mechanistic descriptions of the acylation and deacylation reactions, revealing the rate-limiting step and key interactions within the catalytic triad and Trp185 conformation. [ABSTRACT FROM AUTHOR]