Plastic Materials Research Articles

An investigation of mechanical properties of linden green wood

Abstract This article investigates the mechanical properties of linden green wood, setting out the results of three approaches to assessing tree stability and strength aimed at improving the safety evaluation of living trees. Due to the high moisture content (MC) of green wood and its significant impact on its mechanical properties, data from dried specimens cannot be used to model green wood behaviour. The research was carried out on wood samples with both 40 % and 60 % MC. A non-destructive test (NDT) assessed specimens and measured their vibro-acoustic material properties. Subsequently, destructive static tests were conducted along the three main orthotropic axes of the wood samples. The resulting data led to the development of a bilinear orthotropic model and a comprehensive dataset covering both elastic and plastic material properties. Next, the material properties were optimised to compute and validate a numerical model using the finite element method (FEM). By refining the material properties, the FEM predictions closely matched the experimental results, with a maximum error of 5 %. This information on the wood’s experimental, FEM and NDT-derived properties offers an excellent basis for evaluating linden green wood for many applications.

Isolation, Screening and Identification of Biopolymer Producing Bacillus cereus from Vegetable Wastes

Plastic materials are causing tremendous damage to the environment. To mitigate the use of synthetic plastics, eco-friendly biopolymers have emerged as an alternative to plastics. Biodegradable plastics such as polyhydroxy butyrate (PHB) are currently used in several synthetic applications similar to biopolymers. The present research was conducted to screen bacteria from vegetable wastes for PHB production. The PHB producing bacteria were screened using Sudan Black-B stain followed by microscopic examination for presence of PHB granules. The PHB was produced through a shake flask fermentation method. The significant PHB-producing bacteria was sequenced by 16S rRNA sequencing (1200bp) (NCIMRef: 2023/Seq-160), by NCIM, Pune, India. The sequencing report showed that the bacterial isolate has 99.93% closest homology to Bacillus cereus. Further, we have deposited this sequence in GenBank (SUB14283541 907R_Seq160_CB4 PP422177, SUB14283541 907R_Seq160_CB4_RC PP422178, SUB14283541 704F_Seq160_CB4 PP422179, and SUB14283541 907RC_704F_Seq160_CB4 PP422180) for further reference and studies. The Bacillus cereus CB 4-derived biopolymer precipitated with acetone has shown maximum PHB yield of 2.7 gL-1. Further research prospects would focus on the optimization of biopolymer production and its quality testing on various parameters.

Are Zebrafish Affected by Tiny Plastics in Our Environment?

Zebrafish get their name from the black lines along their bodies. These fish have many similarities with humans and help scientists investigate diseases. Sometimes diseases can be linked to our environment. Since humans started using plastic materials in the last century, we have been filling our soil and water with plastic garbage. With time, plastics break down and become so tiny that they can enter the bodies of many animals, including us. Scientists added one type of these tiny nanoplastics, called polystyrene, into the water where zebrafish eggs were developing. Scientists found that nanoplastics could enter many zebrafish organs and cause the fish to swim differently. Nanoplastics even affected how zebrafish use their genes. Lessons learned from these experiments will help teach people to use fewer plastic products, to be more careful with the way they use plastics, and to come together to find ways to reduce plastic waste.

Development of Light Weight Green Efficient Interlocking Blocks Using Waste Plastics and Industrial Wastes for Low Cost Housing Construction

Annually, billions of metric tonnes of solid waste are produced, including Polyethylene Terephthalate (PET) plastic waste and other industrial manufacturing by-products. This study assesses durability of waste plastic bricks (WPB), which are made by repurposing scrap plastics from PET. Mechanical and fire resistance properties of WPB have been optimised by varying mixing proportions of PET plastic and mixtures of industrial waste materials like fly ash, waste glass powder and concrete debris in ratios of (20:80, 30:70 and 40:60) respectively. This investigation integrates various wastes synergistically to produce bricks, aiming to replace traditional bricks made from cement and clay. This study investigates mechanical and physical properties of interlocking blocks made from mixtures of plastic and industrial waste materials, including fly ash, waste glass powder, and concrete debris. A mixture ratio of 20:80 (plastic to waste materials) yields a compressive strength of 27.3 N/mm², suitable for use in partition walls. Water absorption rates decrease significantly from 3.5% in conventional blocks to 0.5% in 20:80 ratio blocks, with further reductions to 0.43% and 0.40% for 30:70 and 40:60 ratios, respectively, enhancing water resistance. Efflorescence tests indicate improved performance in blocks with higher proportions of alternative materials, meeting highest standards for first-class bricks. Fire resistance tests confirm that all block compositions, including conventional and mixed ratio blocks, achieve a one-hour fire resistance duration, compliant with ASTM E119 standards, ensuring durability and safety of these alternative material blocks.

Transforming Plastic Waste into Fashionable Dresses: An Exploratory Approach for Sustainable Management

Purpose: This study tries to make clothing appealing and sustainable from plastic waste. Design/Methodology/Approach: An in-depth interview was done using (30) people across recycling companies to examine the challenges in recycling plastics in Ghana. Clothing was designed to pay particular attention to the amount of plastic waste used. A cross-sectional quantitative study was done to sort opinions on the possible uses of plastic using one hundred and fifty (150) fashion students. Another cross-sectional quantitative study used one hundred and fifty (150) fashion students to determine the acceptability of clothing made from plastic waste material. Findings: The results showed that the challenge faced in recycling plastic is the high cost associated with the materials and equipment required for recycling. Producing clothing from plastic waste can contribute significantly to reducing plastic waste. Sportswear is the most preferred clothing item from recycled plastic waste. Research Limitation: The research is geographically restricted to the Greater Accra of Ghana. The type of plastic waste material obtained and used in clothing production is limited to plastic waste material generated within the Greater Accra of Ghana. The acceptance of clothing made from plastic waste material is also limited to the researcher’s design presented to participants. Practical Implication: The research transformed plastic waste into usable clothing and examined its acceptability. This provided insights into consumer-acceptable clothing that can be made from recycled plastic waste. Social Implication: The study quantifies how much plastic waste can be recycled into a particular fabric and provides an idea of the quantity of plastic waste that can be removed from the environment based on the number of clothing produced. Originality/Value: The work also employed different methods to make plastic suitable for fabric production and blended recycled plastic with traditional fabrics, which were incorporated into the clothing design. Plastics from their original state were altered to different textures to allow the plastic to be cut into different designs and to fit a particular design for which the plastic waste fabric was used. Textile testing evaluated characteristics like tensile strength, abrasion resistance, shrinkage, breathability, and moisture wicking.

Stability transition conditions of dislocation cores and Peierls stress

At the atomic scale, a dislocation in a crystal possesses two equilibrium cores: One has its symmetric center at the lattice point and is referred to as the O-core; the other has its symmetric center at the middle between two neighboring lattice points and is referred to as the B-core. The possible positions (symmetric centers) of the B-core and the O-core are arrayed alternately, and the dislocation movement undergoes a sequential transformation between the two types of dislocation cores. The core with lower energy is stable, and the energy difference between the O-core and the B-core is the Peierls barrier. It is found that the stability of the core is not fixed. In some materials, the B-one core is stable, and in other materials, the O-core is stable. Furthermore, the core stability can be tuned by exerting pressure or changing the environmental temperature. Because at the stability transition point the energy difference is zero, the Peierls barrier disappears and the dislocation almost moves freely. As a consequence, material plasticity dominated by the dislocation mobility will undergo substantial change in the process of the stability transition. Therefore, it is important to understand under what condition the transition occurs. Using the variational method, the stability phase boundary in the model-parameter space is investigated and the transition condition is approximately described by an analytical equation. Furthermore, it is found that in addition to the disappearance of the Peierls barrier, the B-core and the O-core have the same width at the transition point.

An Evaluation of the Efficacy of Two Different Types of Plastic Waste Materials to Enhance the Geotechnical Characteristics of Soft Clay Soils

Plastic waste materials are constantly increasing around the world as a result of the growing human consumption of these materials day by day, with no actual solutions to get rid of them without causing harm to the environment or the health of living organisms. Therefore, in this research, two types of plastic waste materials are utilized to enhance soft clay soil: polyethylene terephthalate (PET) and nylon (N), in percentages of (1, 1.5, 2, 2.5)% from dry soil weight, to enhance the clay soft soils properties, which are characterized by their excessive compressibility, low bearing capacity, and low shear strength. This study is carried out by conducting laboratory tests before and after the addition. These tests included the unconfined compressive strength (UCS) test, and the other test was the consolidation test. The results revealed a notable rise in the cohesion value (C) when using polyethylene terephthalate (PET), when the enhancement reached 246.42% with 2.5%, while the maximum improvement percent with nylon was 25% with 1.5%. On the other hand, when applied at a rate of 2%, nylon trash was more effective than plastic water bottles (PET) in reducing the compression index (Cc), dropping from 0.26 to 0.15.

Numerical analysis of low-velocity impact damage in fiber metal laminate (FML) by introducing plasticity of fiber composite materials

Numerical analysis of low-velocity impact damage in fiber metal laminate (FML) by introducing plasticity of fiber composite materials

Biodegradable fishing gears: A potential solution to ghost fishing and marine plastic pollution.

Fishing gears are conventionally made from non-biodegradable materials including polyamide (PA). When lost in the ocean, these gears have long-lasting impacts, including marine littering, microplastics production, leaching of chemicals, and an extended period of ghost fishing due to its durability. The use of biodegradable co-polyester material such as polybutylene succinate co-adipate-co-terephthalate (PBSAT) and polybutylene succinate-co-butylene adipate (PBSA) as fishing gear materials have been considered as a potential solution to reduce the associated impact. Ocean is a complex environment in which multiple degradation paths can occur for plastic materials, and decoupling of factors could aid in understanding the impact of each potential factor. In this study, the focus is on the impact of pure water hydrolysis phenomena on biodegradable co-polyester PBSAT and PBSA in comparison to PA monofilaments through accelerated aging at 40°C, 60°C, 70°C and 80°C. As a single factor accelerated aging process, the prediction of loss of mechanical strength over time was possible at other temperatures namely 2°C, 10°C, 15°C, 20°C and 30°C. Different end-of-life criteria were used. This study concluded that solely through pure hydrolysis, a drastic reduction of the time to reach end-of-life criteria was observed by using biodegradable monofilaments instead of PA, but still longer than the expected service time. For example, at 2°C, it would take approximately 10years, 20years and 1000years for PBSAT, PBSA and PA to have lost 50% of their initial stress at break respectively.

Utilization of Fibre-reinforced plastic material as co-firing effect with Prosopis Juliflora in fluidized bed gasifier

Utilization of Fibre-reinforced plastic material as co-firing effect with Prosopis Juliflora in fluidized bed gasifier

Towards polyethylene terephthalate valorisation into PHB using an engineered Comamonas testosteroni strain.

The abundant production of plastic materials, coupled with their recalcitrant nature, makes plastic waste a major challenge as a pollutant. Polyethylene terephthalate (PET) is a polyester formed by polycondensation of terephthalic acid (TPA) and ethylene glycol (EG). This plastic polymer can be completely depolymerized to its monomers using microbial enzymes. In this study, we verified in silico and in vivo that the bacterium Comamonas testosteroni RW31 is able to assimilate TPA and to produce the bioplastic polyhydroxybutyrate (PHB). This bacterium was engineered to heterologously express a fusion of the PET-degrading enzymes FAST-PETase and IsMHETase. We verified that our strain successfully secretes the enzymes and depolymerize PET both in vitro and in vivo, achieving a weight loss of 37.1 % and 0.83 %, respectively. We also studied its capacity to form biofilm. Furthermore, our strain can employ bis(2-hydroxyethyl) terephthalate (BHET), an intermediate of PET degradation, as feedstock to accumulate PHB up to 12.03 % of its dry weight in 14 h. Our findings highlight C. testosteroni RW31 as a promising chassis for synthetic biology strategies aimed at upcycling PET waste.

Settleable microplastics in residential buildings in a Middle Eastern area during warm and cool seasons; quantification, characterization, and human exposure assessment.

Settleable microplastics in residential buildings in a Middle Eastern area during warm and cool seasons; quantification, characterization, and human exposure assessment.

Lessons Learned from Various 3D-Printed Tracheal Grafts in an Extensive Porcine Model for De Novo Tracheal Regeneration.

Lessons Learned from Various 3D-Printed Tracheal Grafts in an Extensive Porcine Model for De Novo Tracheal Regeneration.

The chronic effects of polyethylene terephthalate and biodegradable polyhydroxybutyrate microplastics on Daphniamagna.

The chronic effects of polyethylene terephthalate and biodegradable polyhydroxybutyrate microplastics on Daphniamagna.

Comparison of cellulolytic enzyme treatment and Fenton oxidation for analysis of microplastics in tire rubber particles.

Uncertainties in the quantification of microplastics in various products arise from the applied pretreatment processes. Road dust, a significant source of microplastics, requires precise quantification methods to ensure accuracy. In this study, we examined the impact of pretreatment processes on the accuracy of microplastic quantification in road dust, specifically focusing on tire rubber particles. We compared the effects of cellulolytic enzyme (EZM) and Fenton (FT) treatments by analyzing the changes in particle number, size, shape, and identification accuracy for each treatment. Both treatments increased the number of tire rubber particles, reduced their size, and made them more spherical. Notably, the FT treatment resulted in smaller particle parameters (Feret, MinFeret, Major, Minor, and Area) compared to the EZM treatment. Identification accuracy also varied, with 89% of tire rubber particles identified after EZM treatment, compared to 51% after FT treatment. Furthermore, microplastic volume was overestimated by 4.5% following EZM treatment and underestimated by 21% after FT treatment. These findings demonstrate that pretreatment procedures significantly influence the accuracy of microplastic quantification. Our study underscores the need for further research to determine whether current microplastic estimates are accurate, as the estimated volume can change due to organic removal processes. PRACTITIONER POINTS: Pretreatment to eliminate organic materials is necessary for improving the efficiency of microplastic analysis. Tire rubber particles (TRPs) are a significant plastic material found in urban surfaces. Pretreatment can reduce the size of TRPs and lead to material misidentification of materials. Compared to the Fenton oxidation treatment, cellulolytic enzyme treatment results in less particle fragmentation and volume modification.

Revolutionizing Bioplastic Production: A Focus on Sustainable Alternatives Using Orange Peels and Carboxymethyl Starch: A Review

This review explores the latest developments in bioplastic production, highlighting its key features and emphasizing the environmental significance of utilizing unconventional sources. The study also emphasizes the promising role of orange peels and carboxymethyl starch (CMS) in shaping sustainable alternatives to traditional plastics. The exploration of bioplastic production encompasses the fundamental qualities that set it apart, such as biodegradability, renewability, and reduced carbon footprint. Orange peels, often considered as waste, emerge as a valuable resource in this context, offering a rich source of natural polymers such as pectin. The utilization of orange peels not only contributes to waste reduction but also presents an eco-friendly solution for bioplastic synthesis. Furthermore, the integration of CMS in bioplastic formulations adds another layer of innovation. CMS, as a biopolymer modifier, contributes significantly to the enhancement of the mechanical properties of bioplastics. The discussion encompasses its compatibility with various biopolymer matrices, its impact on the tensile strength and flexibility of resulting bioplastics, and its potential to address challenges associated with conventional plastic materials. As the world seeks alternatives to conventional plastics, the synthesis of bioplastics using orange peels and CMS offers a compelling solution. This review sheds light on the features that make these materials stand out, providing a comprehensive understanding of their potential in reshaping the landscape of sustainable plastic alternatives.

Characterization of Morphological, Thermal, and Mechanical Performances and UV Ageing Degradation of Post-Consumer Recycled Polypropylene for Automotive Industries

Considering the increasing use of plastics in vehicles, the need for sustainable management is becoming a matter of concern. The reintroduction of plastic originated from post-consumer waste in the vehicle manufacturing loop can also be a solution to meet the recent EU ELVs (end-of-life vehicles) legislation in terms of sustainability. This study focuses on post-consumer polypropylene (PP) compounds destined for automotive applications by assessing their morphological, thermal, and mechanical properties. Field Emission Scanning Electron Microscopy (FE-SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques were used. Since the ageing of these materials, caused by the thermo-oxidative degradation process, may compromise their performances, a comprehensive study of their behavior, in comparison to the virgin compound counterpart, was necessary to evaluate the fossil replacement possibility. Furthermore, an additional investigation was conducted after subjecting the materials to UV ageing in order to simulate the degradation effect of solar radiation, with the aim of determining the suitability of the recycled materials in long-term applications. In summary, the results support the feasibility of using recycled post-consumer materials mixed with virgin grade in automotive production, highlighting the stability of thermal and mechanical properties, critical for efficient manufacturing. This research underlines the noteworthy progress in the circularity of automotive plastics, providing a sustainable solution for integrating plastic material waste into new vehicle production.

STUDY OF PROPERTIES AND USE OF A SEPARATE FRACTION OF GOSSYPOL RESIN

The work was carried out on gossypol resin, which was considered a waste product of the oil industry. The fractional composition and formula of gossypol resin are presented, and its physicochemical properties are analyzed. The chemical structure of the fraction isolated from gossypol resin is determined by infrared spectroscopic analysis. Preliminary studies are conducted to determine the composition and properties of this fraction. Its use as a raw material for obtaining secondary products is proposed. A scheme of thermal extrusion and a mechanism for obtaining molding plastic materials (PSM) from gossypol resin are presented.

Assessment of macro litter pollution and potential sources in the shorelines of two Mediterranean lakes in Isparta, Turkey: a first report.

Anthropogenic litter pollution is recognized as a critical environmental issue by the United Nations Environment Program (UNEP), with factors like climate change and population growth intensifying the issue. This study aims to assess the abundance and pollution status of macro litter (> 3cm) in two key freshwater basins in the Mediterranean region of Turkey: Lake Eğirdir and Lake Kovada. Macro litter sampling was conducted along the shorelines of both lakes, and pollution levels were measured using the Clean Coast Index (CCI), Clean Environment Index (CEI), and Cigarette Butt Pollution Index (CBPI). In total, 6688 litter items were collected from Lake Eğirdir, and 10,313 from Lake Kovada. Plastic and polystyrene materials dominated the litter composition in both lakes, with mixed packaging being the most common source. However, at the C2 station in Lake Kovada, domestic litter was the most abundant. According to the CCI, all stations except E5 were classified as "dirty-very dirty." The CEI results showed that stations E1, E7, K1, C1, and C3 had similar pollution levels. Based on the CBPI, stations E1 and C3 were considered "polluted." Given the potential volume and sources of plastic litter, it is crucial for the government to collaborate with local stakeholders, including farmers, fisheries, industries, hotels, and tourism operators along the shores of Lake Eğirdir and Lake Kovada. For instance, plastic bottles and bags, which are commonly discarded from hotels and recreational areas, represent a major source of pollution in both regions. This research represents the first study on anthropogenic litter in these freshwater ecosystems. The findings emphasize the need for immediate policy actions and effective waste management strategies to reduce macro litter pollution in these critical freshwater habitats of the Mediterranean region.

Effects of treated high-density polyethylene admixtures on the compressive strength of concrete in sulphates and acids environments

Using plastic materials in cementitious matrices has spurred studies with the potential for sustainable concrete production. This study investigated the effect of high- density polyethylene (HDPE) on the compressive behavior of concrete in sulphates and acidic environments. The HDPE was pulverised and chemically treated with 20% hydrogen peroxide. The admixture was then added by the weight of cement in percentages (0, 0.25, 0.5, 0.75, and 1) to make concrete of 25 and 50 grades using 150mm3 steel moulds. Water-to-cement ratios of 0.4 and 0.36 were chosen. The cubes were initially cured in water for 28 days before being immersed in 10% tetraoxosulphate (vi) acid and 10% magnesium sulphate for 7, 28, and 90 days. The Strength Deterioration Factor (SDF) was then determined. The findings revealed that after 90 days of exposure, grade M25 cubes lost a maximum of 85.20% of their strength, while grade M50 cubes lost 76.69%. However, resistance to sulphate attack decreased with HDPE dose; grade M25 cubes showed the lowest strength loss of 5.7%, while grade M50 cubes showed the lowest strength loss of 4.67% both with 1% HDPE by weight of cement. The study concluded that pulverised and treated HDPE could improve concrete's resistance to sulphates. The study’s insights portend significant prospects for the production of sulphate-resistant cement while reducing the menace of plastic waste disposal. The study recommends the use of 1% pulverised HDPE by weight of cement for the production of concrete in sulphate resilient infrastructures.