Types Of Plastic Research Articles

Study on the laser self-fusion welding process, microstructure, and properties of 6082 aluminum alloy

Abstract In order to improve the welding efficiency and performance of aluminum alloy thin-walled structural components in the fields of projectiles, aerospace, and rail transportation, this paper studies the rapid laser self-fusion welding process, joint microstructure, and mechanical properties of 2 mm-thick 6082 aluminum alloy. The results show that through the exploration of process parameters, six groups of welds with good forming and no metallurgical defects are obtained, and the fastest speed reaches 6 m/min. The weld microstructure consists of a large amount of α-Al matrix and a small amount of Mg2Si phase. The hardness of the welded joint is 75.89 - 79.08 HV, reaching more than 84% of the base metal hardness; the average tensile strength is 224.5 MPa, reaching 81% of the base metal. This is due to the disappearance of the work hardening effect in the weld and heat-affected zone and the reduction of the Mg2Si strengthening phase caused by the evaporation and burn loss of low-boiling-point elements, resulting in the softening phenomenon. The tensile fracture morphology is a typical plastic fracture feature.

Occurrence and migration of synthetic phenolic antioxidants in food packaging materials: Effects of plastic types and storage temperature.

Occurrence and migration of synthetic phenolic antioxidants in food packaging materials: Effects of plastic types and storage temperature.

Catalytic co-pyrolysis of PET/PP plastics and olive pomace biomass with marble sludge catalyst

Sustainable and efficient waste management requires involvement of symbiotic solutions to various types of wastes, and so to achieve circular economy. Through this motivation, in this study, combined thermochemical conversion (pyrolysis) of plastics, biomass and marble processing effluents physicochemical treatment sludge (K1) were studied. In this combination, plastics were petroleum-based synthetic aromatic (PET) and aliphatic (PP) organics, while olive pomace-OP was natural agricultural residue. K1 was mineral product, which was first introduced in the literature as pyrolysis catalyst by the authors. In the study, co-pyrolysis of polymers and biomass was catalyzed by mineral waste containing CaCO3. The effect of plastic type and pyrolyzed material mixture ratio on pyrolysis fractions were investigated. Moreover, material recovery potential from pyrolysis fractions were discussed. In catalytic co-pyrolysis, by increasing the plastic ratio in the mixture, the pyrolytic liquid and oligomer fraction increased while the solid (char) and gas fraction decreased. For 70%PP+15%OP+15%K1 mixture, liquid product was dominant, whereas with 60%PET+20%OP+20%K1 much more pyrolytic gas fraction produced. The thermal degradation of char products did not exceed 2-3% up to 600°C and this stability continues up to approximately 700°C reveals the potential of the char to be used in alternative areas as a material with high thermal resistance. The catalytic co-pyrolysis liquid products contain alkanes, alkenes, acids, phenols, benzene, aldehydes, esters, alcohols, ketones. Benzene, acid and alcohol groups were dominant in liquids, while alkane, alkene and alkyne groups were dominant in gases.

Surveys of Knowledge and Awareness of Plastic Pollution and Risk Reduction Behavior in the General Population: A Systematic Review.

Individual attitudes and knowledge can predict pro-environmental behaviors. Public surveys, therefore, can provide precious information, which can guide sensitization interventions. In this systematic review, we searched Medline and Embase, with no language or date restrictions, for surveys designed to measure in the general population the level of knowledge about different types of plastics, the risks associated with plastic pollution, and awareness of actions to reduce them. Survey tools were analyzed following the guide of Burns and Kho, and study methodological quality was assessed via the Appraisal Tool for Cross-Sectional Studies. We included 17 articles published from 2019 to 2024, mostly concerning European populations. The tools comprised a median of 13 items (range 7-50), and very differently formulated questions. Overall, 13/17 (76.5%) study questionnaires received less than 50% (<3.5) of the maximum possible score. The remaining four questionnaires obtained intermediate scores (between 3.5 and 5.3) indicating moderate quality. Most studies did not employ the appropriate cross-sectional survey methodology, only two studies statistically justified sample sizes, only three reported a sampling frame, and only two described a selection process that appears to be representative. In most cases, the instruments were not validated, and the statistical significance of key variables was not provided. The many shortcomings highlighted in this review emphasize the urgent need for methodological rigor when conducting survey studies, which are essential tools for public health.

Microplastic Categories Distinctively Impact Wastewater Bacterial Taxonomic Composition and Antimicrobial Resistance Genes.

Wastewater treatment plants (WWTPs) may serve as hotspots for pathogens and promote antimicrobial resistance (AMR). Plastic debris in wastewater could further contribute to AMR dissemination. The aim of this study was to investigate the impact of various microplastic types on bacterial communities and AMR gene abundance in wastewater that were obtained from two WWTPs, one in Tromsø, Norway, and the other one in Potchefstroom, South Africa. The microcosm experiments were designed as follows: Five manufactured microplastic pellet types were used for testing, and two rock aggregate types were used as controls. In addition, each material type was subjected to artificial aging treatments using either ultra-violet light or hydrogen peroxide. Each material was incubated in flasks containing inlet/outlet wastewater obtained from these two WWTPs. Nucleic acids were extracted after a one-week incubation period. The detection of the blaFOXand blaMOX genes was performed using quantitative PCR. Extracted DNA was sequenced using a MinION device. Non-metric multi-dimensional scaling plot on full-length 16S sequencing data at the species level showed that samples were clustered into distinct material groups, which were in line with the ANOSIM test. The Indicator Species Analysis showed a strong association between many Acinetobacter species with the plastic group than the rock group. Aging treatment using hydrogen peroxide showed some effects on microbial composition in the outlet wastewater. The abundance of blaFOX and blaMOX genes in the Norwegian wastewater outlet were generally lower compared to those in the inlet, though the results were contrary in South African wastewater samples. The relative abundance of AMR genes seemed to be increased on several plastic types (PET, PE, and PLA) but decreased on PVC-A. WWTP treatments in this study did not effectively reduce the abundance of AMR genes. An in-depth understanding the role of specific microplastic type on bacterial communities and AMR profiles is, therefore, needed to combat AMR threat.

Biodegradation potential of low-density polyethylene (LDPE) using Aspergillus niger and Phanerochaete chrysosporium

Low-density polyethylene (LDPE) is one of the most predominant and widely used plastic types on earth. This study investigated the degradation of low-density polyethylene (LDPE) with two fungal species. Aspergillus niger and Phanerochaete chrysosporium were the two fungal species that were isolated from garbage soil and screened in two medium broths independently i.e. Czapek-Dox broth (CDB) and Mineral salt medium (MSM). The broth was used to inoculate both fungi species in flasks where LDPE polymer as source of carbon. Non pre-treatment LDPE samples were incubated for a 20-day biodegradation process. Microbial population, biomass layer, pH were maintained during the process. The final biodegradation percentage after 20 days was 40% in CDB and minimum degradation rate in MSM. The morphological, structural and functional group alterations on LDPE were assessed using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). DSC analytical method confirmed the LDPE polymer chain breakdown. LDPE exposed to fungi species was reported to show crystallinity and crystal size differences with peak intensity at 21.4°. Through the analysis of FTIR peaks were observed at 2927 and 2523 cm−1. This research highlights the potential of both fungi for biodegradation of LDPE. However, with these findings adaptive metabolic pathways for LDPE biodegradation need to be linked and studied.Graphical

Bacterium-Phage Symbiosis Facilitates the Enrichment of Bacterial Pathogens and Antibiotic-Resistant Bacteria in the Plastisphere.

The plastisphere, defined as the ecological niche for microbial colonization of plastic debris, has been recognized as a hotspot of pathogenic and antibiotic-resistant bacteria. However, the interactions between bacteria and phages facilitated by the plastisphere, as well as their impact on microbial risks to public health, remain unclear. Here, we analyzed public metagenomic data from 180 plastisphere and environmental samples, stemming from four different habitats and two plastic types (biodegradable and nonbiodegradable plastics) and obtained 611 nonredundant metagenome-assembled genomes (MAGs) and 4061 nonredundant phage contigs. The plastisphere phage community exhibited decreased diversity and virulent proportion compared to those found in environments. Indexes of phage-host interaction networks indicated significant associations of phages with pathogenic and antibiotic-resistant bacteria (ARB), particularly for biodegradable plastics. Known phage-encoded auxiliary metabolic genes (AMGs) were involved in nutrient metabolism, antibiotic production, quorum sensing, and biofilm formation in the plastisphere, which contributed to enhanced competition and survival of pathogens and ARB hosts. Phages also carried transcriptionally active virulence factor genes (VFGs) and antibiotic resistance genes (ARGs), and could mediate their horizontal transfer in microbial communities. Overall, these discoveries suggest that plastisphere phages form symbiotic relationships with their hosts, and that phages encoding AMGs and mediating horizontal gene transfer (HGT) could increase the source of pathogens and antibiotic resistance from the plastisphere.

Combined BPA and DIBP Exposure Induced Intestinal Mucosal Barrier Impairment Through the Notch Pathway and Gut Microbiota Dysbiosis in Mice.

Bisphenol A (BPA) and diisobutyl (DIBP) phthalate are widely used as typical plasticizers in food packaging. Plasticizers can be released from polymers, migrate into food, and be ingested by humans, leading to various health problems. However, little research has investigated the combined toxicity of BPA and DIBP, particularly their intestinal toxicity. Our goal is to analyse the combined toxicity of BPA (50 mg/kg) and DIBP (500 mg/kg) on the intestines of KM mice. Additionally, we tried to find natural products that can inhibit or prevent the combined toxicity of BPA and DIBP. The results indicated that the combination of BPA and DIBP exposure resulted in a reduction of beneficial flora, an increase in D-Lac levels (136 ± 14 μmol/L), an increase in intestinal permeability, activation of the notch pathway, and a decline in intestinal stem cells (ISCs) to goblet cells, compared to single-exposure sources. Nevertheless, Rubus chingii Hu phenolic extract (RHPE) (200, 400 and 600 mg/kg) ameliorated the BPA and DIBP-induced intestinal microbiota disruption and intestinal mucosal barrier impairment by inhibiting the overactivation of the notch pathway. The results of this study highlight the potential risks to human health posed by the combination of BPA and DIBP and may help explain the potential pathways of enterotoxicity caused by combined ingestion.

Water: Impacts of plastic pollution on human health and biological systems

Current spare of human development consisting of advancements in science and technology that led to the synthesis of plastics, polymers with diverse benefits in human endeavours; and on the other hand, the need for quality water is more intensified nowadays. Plastics pollution is rising due to mismanagement, and inturn causing contamination of water bodies and ultimately affecting biological systems. A review of literatures pertaining water, plastics and water pollution was done to fulfill the objective of this study. This study examines the harmful effects of plastics in water on human health and biological systems. Plastics, widely used in daily life, contaminate water sources, posing significant health risks. This review explores the role of water in biological systems, types of plastics, sources of plastic pollution, harmful chemicals conveyed by plastics, and management strategies.This paper concludes that behavior change, effective waste management, effective water supply and treatment, awareness creation may contribute greatly in controlling water pollution caused by plastic pollution.

Co-Pyrolysis of Plastic Waste and Lignin: A Pathway for Enhanced Hydrocarbon Recovery

Various plastics and biomass wastes, such as polypropylene (PP), low- or high-density polyethylene (LDPE/HDPE), and lignin, have become some of the most concerning wastes nowadays. In this context, this study aimed to investigate the possibility of applying thermochemical processes for the valorization of these materials. The experiments were carried out using a thermogravimetric analyzer on individual plastic and lignin samples and their mixtures at different mass ratios of 1:1, 1:2, 1:3, and 1:4. The gaseous products evolved during the pyrolysis process were analyzed by combined thermogravimetric and Fourier-transform infrared spectroscopy (TG-FTIR) and chromatography-mass spectrometry (Py-GC/MS) to analyze the functional groups and chemical composition of the obtained pyrolysis products. The results showed that the main functional groups of lignin monitored by TG-FTIR were aromatic and aliphatic hydrocarbons, while all plastics showed the same results for hydrocarbons. The investigation confirmed that mixing these types of plastics with lignin at different mass ratios led to increased recovery of higher-value-added products. Py-GC/MS analysis showed that the greatest results of compound recovery were achieved with lignin and LDPE/HDPE mixtures at 600 °C. At this temperature and with a mass ratio of 1:3, the plastic’s radicals enhanced the depolymerization of lignin, encouraging its wider decomposition to hydrocarbons that can be applied for the production of value-added chemicals and bio-based energy.

Invasion and ecological impact of the biofouling tube worm Hydroides elegans (Polychaeta: Serpulidae) in Korean coastal waters

Biofouling, the colonization of submerged surfaces by organisms including microorganisms, plants, algae, and animals, involves both natural and artificial environments. The serpulid worm Hydroides elegans, known as an invasive species in global port areas, creates extensive aggregations of calcareous tubes. In 2019, H. elegans was found attached to the research vessel ISABU in Korea, and a phylogenetic analysis was conducted to identify the species and determine its genetic characteristics. Following its detection, mesocosm experiments with plastic panels (PP, PE, PET, and EPS) were undertaken to investigate its recruitment and adaptation processes within new ecosystems. During the 12-week experiment, the biomass of H. elegans increased on all plastic types, significantly contributing to the overall biomass accumulation. This invasive species has replaced the previously prevalent native species Hydroides ezoensis, achieving dominance over other taxonomic groups in biomass. These findings demonstrate the significant ecological disruptions caused by non-indigenous species introduced through maritime activities, highlighting the urgent need for enhanced preventative and monitoring strategies

Antibacterial thermoplastic starch/sepiolite bio-nanocomposite films: Effects of plasticizer type and starch source

The use of starch-based films as an alternative food packaging has gained prominence as part of efforts to ensure sustainability and manage post-user waste, aligning with European regulations and broader global sustainability goals. In this study, Thermoplastic starch (TPS) bio-nanocomposite hybrid films were developed by incorporating high purity sepiolite (HPS) and Turkish oregano extract (OE) as reinforcement and antimicrobial additives, respectively. The interactive effects of four experimental variables (temperature, time, plasticizer type, and ratio) on the mechanical characteristics of corn and potato starch-based films were evaluated using Box-Behnken response surface methodology. A three-level, three-factor Box-Behnken design was utilized to investigate the effects of the experimental variables on tensile strength (TS), elongation at break (EB), and E-modulus (EM) of the starch-based films. The potato-based TPS films using sorbitol rather than glycerol exhibited better mechanical properties than corn starch-based TPS films under the optimized experimental parameters of 70°C gelatinization temperature, 60 minutes gelatinization time, and 40% sorbitol plasticizer. The addition of 3% HPS slightly enhanced the mechanical (TS: 26.0 MPa, EB:11.3%, and EM:1817 MPa) and oxygen permeability characteristics (OTR: 25 cc/m2.day) of the potato-based bio-nanocomposite films. The hybrid films prepared with the addition of OE provided &gt;99.7% antibacterial resistance to E. coli and S. aureus bacteria (in accordance with ASTM D3985). These findings suggest that starch-based hybrid films offer a promising approach to address both environmental and food safety concerns, raising the prospect of using such films as innovative active packaging materials in the future.

Microplastic accumulation in various bird species in Turkey.

Plastic pollution constitutes one of the major environmental problems of our time, and in recent years, it has emerged as a significant threat to the environment and to various organisms, including bird species. In this context, this study, which provides the first data in Türkiye, aimed to determine the level of microplastic (MP) pollution in 12 bird species (Eurasian buzzard; short-toed snake-eagle; white stork; northern long-eared owl; common barn-owl; ruddy shelduck; Eurasian eagle-owl; scarlet macaw; common pheasant; Indian peafowl; common kestrel; and gray parrot). The results indicate that MPs were detected in 50% of the specimens (n = 20), with an average of one MP/item per individual. With an average of three MPs per individual, the short-toed snake-eagle was found to be the species with the highest MP accumulation. Fibers (range: 51-534 µm) were the most common type of plastic found in the gastrointestinal tract of birds, with ethylene vinyl acetate and navy blue being the most common polymer type and color, respectively. It was also found that the abundance of MPs increased with the weight of specimens, contributing to the hypothesis that there is a correlation between the size/weight of animals and increased levels of MP accumulation. These findings highlight the impact of plastic pollution on birdlife and the need for further monitoring to assess the ecological impact of pollution.

High Captured Carbon Content Bioplastic Film from Spirulina

AbstractBioplastics offer a solution to the problem of increasing atmospheric CO2 levels contributed by the linear production and consumption pattern of fossil‐derived plastics by closing the carbon loop with material sourcing from biomass and bioplastic's biodegradability. Spirulina, a genus of cyanobacteria that is capable of rapid CO2 uptake, can be the key to realizing a circular plastic economy by converting atmospheric CO2 to value‐added high protein content biomass, from which the protein can be extracted and processed to produce protein‐based bioplastics with high captured carbon content that is biodegradable, releasing CO2 after decomposition to be returned to the cycle. To demonstrate the feasibility of utilizing the self‐assembling capabilities of Spirulina protein to fabricate bioplastics, a simple procedure is proposed that involves protein isoelectric point precipitation followed by solvent casting to produce an entirely Spirulina protein‐based bioplastic film containing glycerol as the plasticizer without blending with other types of conventional plastics. By further crosslinking with carboxymethylcellulose and Ca2+ cations, are able to obtain films with the highest average tensile strength of 5.5MPa. Additionally, the Spirulina protein films showed potential in UV‐blocking applications and exhibited good biodegradability.

Advancing PET-Degrading Enzymes through Directed Evolution to Combat Plastic Pollution

Plastic pollution poses a significant environmental challenge due to its persistence and widespread distribution. Among various types of plastic, polyethylene terephthalate (PET) is especially problematic due to its resistance to natural degradation. PET-degrading enzymes, particularly PETases and cutinases, have emerged as promising solutions for enzymatic plastic recycling. However, their native catalytic efficiency and thermostability are limited. Directed evolution has enabled the development of improved enzyme variants through techniques such as error-prone PCR, DNA shuffling, and saturation mutagenesis. This review highlights recent advances in engineering Cutinase and PETases, focusing on enhancing catalytic efficiency and thermostability for PET plastic degradation by directed evolution. Key engineered variants, including HotPETase and optimized leaf-branch compost cutinase (LCC) mutants, demonstrate significant progress toward sustainable plastic recycling through enzymatic means.

Evaluation of char properties from co-pyrolysis of biomass/plastics: effect of different types of plastics

Evaluation of char properties from co-pyrolysis of biomass/plastics: effect of different types of plastics

Discovery of potentially degrading microflora of different types of plastics based on long-term in-situ incubation in the deep sea.

Discovery of potentially degrading microflora of different types of plastics based on long-term in-situ incubation in the deep sea.

Composite materials from waste plastics: A sustainable approach for waste management and resource utilization

The increasing production and improper disposal of plastic waste present a major global environmental challenge, highlighting the need for sustainable solutions. This review thoroughly examines the use of waste plastics in composite material production, providing a dual benefit: reducing environmental impact while creating valuable materials. This review examines the scale and ecological impact of plastic waste, focusing on various types of waste plastics, such as thermoplastics and thermosets. In-depth discussion includes various processing techniques such as melt blending, compression molding, extrusion, and injection molding. The review discusses various reinforcing materials used with waste plastics, including other polymers, natural and synthetic fibers, sand, clay, fly ash, and additional recycled materials. The focus is on analyzing mechanical, thermal, physical, and chemical properties, considering factors like waste plastic-type, reinforcement type, processing parameters, and additives. This review serves as a valuable resource for researchers, engineers, and policymakers aiming to find sustainable solutions for plastic waste management and to promote a circular economy.

Chemical characterization of polymer and chloride content in waste plastic materials using pyrolysis - direct analysis in real time - high-resolution mass spectrometry.

The increasing global demand for plastic has raised the need for effective waste plastic management due to its long lifetime and resistance to environmental degradation. There is a need for rapid plastic identification to improve the mechanical waste plastic sorting process. This study presents a novel application of Temperature-Programmed Desorption-Direct Analysis in Real Time-High Resolution Mass Spectrometry (TPD-DART-HRMS) that enables rapid characterization of various plastics. This technique was applied on four commercially available reference polymers (polyethylene, polypropylene, polystyrene, polyvinyl chloride) as well as three "waste" plastic samples of mixed origin. These waste plastic samples were obtained as discards from various industrial processes with limited analytical characterization data. Through the application of CH2 Kendrick mass defect (KMD) grouping, characteristic trends in the mass spectra of each sample were identified, allowing for a simplified numerical comparison. This approach utilized a robust statistical approach using the Tanimoto coefficient, allowing for the quantitative measures of similarity between standards and unknown samples. The application of this mathematical evaluation methodology was used to identify plastic types and to distinguish structurally similar polymers. Additionally, we report that a chloride ion clustering effect with copper substrate can identify chlorinated polymer PVC (polyvinyl chloride) utilizing pyro-(-)DART-HRMS mode. PVC polymer is of particular interest in recycling due to its high chloride content, which can present technical challenges for some types of recycling. We found that chloride ion clusters are a good screening marker for the presence of chlorinated polymers in mixed waste plastic samples. This study can possibly help advance rapid and accurate analytical techniques for identifying the composition of waste plastics to advance the effectiveness of the waste plastic sorting process.

A straightforward protocol for extracting microplastics from freshwater sediment with high organic content

Extracting microplastics from sediment is critical in assessing pollution in freshwater environments. However, this process can be particularly challenging for clayey sediments with a significant organic matter content. This study proposes a simplified method for extracting microplastics from organic-rich clayey sediments and a complete protocol for sediment processing. To evaluate the extraction method, calcined clayey sediment was artificially enriched with varying organic content (20, 40, and 60%). Known quantities of plastic particles with distinct characteristics and compositions (PET, HDPE, PP, PE, and PS) were introduced into these artificial organic sediments, mixed with a saline solution, centrifuged, and then assessed the recovery rate. The recovery rate exceeded 83% for the five selected plastic types. Additionally, the method minimized particle loss by reducing the number of transfers between containers, a common issue in other microplastic extraction protocols. Based on the efficiency of the extraction method, we proposed and applied a protocol for environmental samples. The protocol comprises five key steps: (1) drying sediment samples, (2) density separation, (3) filtering, (4) digestion of organic matter, and (5) visual analysis. This protocol extracted a wide variety of microplastics with diverse shapes, colors, sizes, and polymeric compositions. These results demonstrate that the proposed protocol is both straightforward and effective in extracting plastic particles commonly found in clayey sediments of freshwater systems. Moreover, the protocol employs inexpensive, readily available, and environmentally friendly reagents, making it a more sustainable alternative to other methodologies for extracting microplastics from environmental matrices.