Type Of Plastic Material Research Articles

Plastic Polymers and Antibiotic Resistance in an Antarctic Environment (Ross Sea): Are We Revealing the Tip of an Iceberg?

Microbial colonization of plastic polymers in Antarctic environments is an under-investigated issue. While several studies are documenting the spread of plastic pollution in the Ross Sea, whether the formation of a plastisphere (namely the complex microbial assemblage colonizing plastics) may favor the spread of antibiotic-resistant bacteria (ARB) in this marine environment is unknown yet. A colonization experiment was performed in this ecosystem, aiming at exploring the potential role of plastic polymers as a reservoir of antibiotic resistance. To this end, the biofilm-producing activity and the antibiotic susceptibility profiles of bacterial strains isolated from biofilms colonizing submerged polyvinylchloride and polyethylene panels were screened. The colonization experiment was carried out at two different sites of the Ross Sea, namely Road Bay and Tethys Bay. Most of bacterial isolates were able to produce biofilm; several multidrug resistances were detected in the bacterial members of biofilms associated to PVC and PE (also named as the plastisphere), as well as in the bacterial strains isolated from the surrounding water. The lowest percentage of ARB was found in the PE-associated plastisphere from the not-impacted (control) Punta Stocchino station, whereas the highest one was detected in the PVC-associated plastisphere from the Tethys Bay station. However, no selective enrichment of ARB in relation to the study sites or to either type of plastic material was observed, suggesting that resistance to antibiotics was a generalized widespread phenomenon. Resistance against to all the three classes of antibiotics assayed in this study (i.e., cell wall antibiotics, nucleic acids, and protein synthesis inhibitors) was observed. The high percentage of bacterial isolates showing resistance in remote environments like Antarctic ones, suffering increasing anthropic pressure, points out an emerging threat with a potential pathogenic risk that needs further deepening studies.

Polyethylene Terephthalate Microplastics Generated from Disposable Water Bottles Induce Interferon Signaling Pathways in Mouse Lung Epithelial Cells.

Microplastics (MPs) are present in ambient air in a respirable size fraction; however, their potential impact on human health via inhalation routes is not well documented. In the present study, methods for a lab-scale generation of MPs from regularly used and littered plastic articles were optimized. The toxicity of 11 different types of MPs, both commercially purchased and in-lab prepared MPs, was investigated in lung epithelial cells using cell viability, immune and inflammatory response, and genotoxicity endpoints. The underlying mechanisms were identified by microarray analysis. Although laborious, the laboratory-scale methods generated a sufficient quantity of well characterized MPs for toxicity testing. Of the 11 MPs tested, the small sized polyethylene terephthalate (PETE) MPs prepared from disposable water bottles induced the maximum toxicity. Specifically, the smaller size PETE MPs induced a robust activation of the interferon signaling pathway, implying that PETE MPs are perceived by cells by similar mechanisms as those employed to recognize pathogens. The PETE MPs of heterogenous size and shapes induced cell injury, triggering cell death, inflammatory cascade, and DNA damage, hallmark in vitro events indicative of potential in vivo tissue injury. The study establishes toxicity of specific types of plastic materials in micron and nano size.

An Overview of the Sustainable Depolymerization/Degradation of Polypropylene Microplastics by Advanced Oxidation Technologies.

Plastics have become indispensable in modern society; however, the proliferation of their waste has become a problem that can no longer be ignored as most plastics are not biodegradable. Depolymerization/degradation through sustainable processes in the context of the circular economy are urgent issues. The presence of multiple types of plastic materials makes it necessary to study the specific characteristics of each material. This mini-review aims to provide an overview of technological approaches and their performance for the depolymerization and/or degradation of one of the most widespread plastic materials, polypropylene (PP). The state of the art is presented, describing the most relevant technologies focusing on advanced oxidation technologies (AOT) and the results obtained so far for some of the approaches, such as ozonation, sonochemistry, or photocatalysis, with the final aim of making more sustainable the PP depolymerization/degradation process.

Optimizing Degradable Plastic Density Prediction: A Coarse-to-Fine Deep Neural Network Approach

Density is an important property for the production of high-quality degradable plastics. Density is useful to determine the type of plastic material and to detect physical changes in the plastic material. In this paper, a novel technique for predicting the density of degradable plastics using Deep Neural Networks (DNN) is presented. The aim was to reduce the dimension of the inputs in order to establish a strong relationship between the inputs using principal component analysis (PCA). The results show that the combination of polyethylene, oil palm biomass, starch and palm oil has a greater impact on predicting the density of degradable plastics. Subsequently, the number of hidden neurons is determined by a coarse-to-fine search to develop the network topology of the DNN model for predicting the density of degradable plastics. The developed DNN model consists of 4 input neurons, 62 neurons in the first hidden layer, 31 neurons in the second hidden layer and one output neuron. The developed DNN model showed high accuracy with the lowest values for RMSE, MAE and MSE, indicating that the use of a DNN model is a suitable method for predicting the density of degradable plastics. Furthermore, this study has the potential to make rapid and accurate predictions about the physical properties of degradable plastics in the context of polymers.

Culture dependent analysis of bacterial activity, biofilm-formation and oxidative stress of seawater with the contamination of microplastics under climate change consideration

Temperature changes due to climate change and microplastic contamination are worldwide concerns, creating various problems in the marine environment. Therefore, this study was carried out to discover the impact of different temperatures of seawater exposed to different types of plastic materials on culture dependent bacterial responses and oxidative characteristics. Seawater was exposed to microplastics obtained from various plastic materials at different temperature (−18, +4, +20, and +35 °C) for seven days. Then microplastics were removed from the suspension and microplastic-exposed seawater samples were analyzed for bacterial activity, biofilm formation and oxidative characteristics (antioxidant, catalase, glutathione, and superoxide dismutase) using Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. The results showed that the activity and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus were affected through oxidative stress by catalase, glutathione, and superoxide dismutase due to the microplastic deformation by temperature changes. This study confirms that temperature changes as a result of climate change might influence microplastic degradation and their contamination impact in seawater in terms of bacterial metabolic and oxidation reactions.

Agricultural Plastic Waste Management

This article aims at describing both the studies and results implemented in the framework of the H2020-EU research project “RECOVER: New bio-recycling routes for food packaging and agricultural plastic waste” which deals with the sustainability of innovative biodegradation processes for plastic waste and production, in any environmental, social, economic and safety matters. In such a framework, the POLOG University Centre (Livorno, Italy), reconstructed and analyzed the actual farm plastic waste supply chain, as described in the following sections. The first section is introductive and it has been intended as a primer to the most common different types of plastic materials. The second section has deserved to be a state of the art on the most relevant issues raised in plastic waste management. The third section deals with suitable approaches to address the environmental side effects of rapidly growing plastics production, use, and disposal. Some of these approaches were listed, such as physical treatment of the polymeric components, plastic reduction use and employment as much as mechanical and/or chemical recycling and energy recovery. The fourth section shows how some of the above main issues, which raise coping with plastic reduction and recycling, are suited to be coped with from a logistics perspective. Such logistics belong to the basic needs due to tackling any plastic waste supply chain, i.e. collection and transport to intermediate stock and final delivery to recycling plants and/or brownfields, applying the set of methodologies and techniques drawn from the well-known field of pick-up-anddelivery models. These last tasks become crucial when the main effort has addressed the enforcement of any feasible changes from the use of items made in old high environmental intrusive to their replacement with new agricultural and biodegradable plastics. The paper goes to end presenting shortly of a few suitable solutions that could be proposed and applied to the entire plastic waste supply chain. Finally, some concrete aspects of each phase of the supply chain were discussed and it was highlighted how much each of these can be best used in addressing the problem known throughout the world as the problem of the emergency of old plastic waste.

Elucidating the water-hammer surge behaviour in steel / high and low density PolyEthylene -based piping systems

ABSTRACT The in-series connections of multi-pipes involving steel and polymeric materials were identified as being an effective design tool to extenuate water-hammer surges induced into an existing steel-main pipe-based hydraulic system. Although this design measure significantly reduced the magnitude of pressure-wave surges, it was limited by the expansion of the period of pressure-wave oscillations. This study addressed a holistical exploration and comparison of the effectiveness of the in-series connections of multi-pipes design measure used to control water-hammer surges into an existing steel water distribution piping systems. The extended one-dimensional water-hammer model, including the Vitkovsky and Kelvin-Voigt formulations, was developed to describe the transient flow, together with the Method of Characteristics implemented for numerical computations. The comparison of the numerical solution with observed data, quoted in the literature, and the alternative numerical solution demonstrated the accuracy of the developed solver. The test case appraised the capability of a variety of in-series setups of steel and plastic main-pipes for a reservoir-pipe-valve – based hydraulic system. The high- and low-density polyethylene (HDPE and LDPE) plastic material types were considered in this investigation. Results showed that the hydraulic system setup built upon an (LDPE-steel-LDPE) provided a satisfactory tradeoff between the dampening of pressure-wave magnitude and the expansion of the period of pressure-wave oscillations

Development and validation of multi-analyte methods for the determination of migrating substances from plastic food contact materials by GC-EI-QqQ-MS and GC-APCI-QTOF-MS

The packaging has proven to be a source of some serious food contaminants, with several chemicals migrating from the food contact material into the food. Therefore, efficient means of control of the migration extend and identification of the migrating substances must be established. The necessity of migration tests has been underlined by the European Union (EU) Regulation No. 10/2011, requiring the evaluation of the presence of intentionally and non-intentionally added substances. To facilitate this purpose, highly sensitive, multi-analyte methods are required. Targeting a wide range of volatile migrating compounds, we developed and validated a GC-EI-QqQ-MS and a GC-APCI-QTOF-MS method for the simultaneous determination of 131 and 126 food packaging substances, respectively. Even though the GC-EI-QqQ-MS method presented increased sensitivity for several of the investigated compounds, covering the existing EU requirements and specific migration limits (SMLs) for all targeted analytes; the complementary high-resolution method inherently enables the possibility of further utilization of the obtained raw data among others for retrospective analysis. The applicability of both methods was tested using 95% v/v aqueous ethanol food simulant, representative for the worst foreseeable conditions of intended use for many food contact material applications. Real food packaging samples belonging to different types of plastic materials were tested toward chemical migration, utilizing different migration protocols, depending on the sample characteristics. The favorable analytical features of both methods enable their use for the direct analysis of the investigated food simulant, overcoming the need for sample preparation. Thus, labor intensive and/or time-consuming pre-concentration procedures, which would furthermore restrict the applicability of the methods to certain groups of analytes and add to the uncertainty of the overall results, could be eliminated.

Optimization of mechanical properties of carrageenan-based bioplastic as food packaging

Several types of plastic materials are widely used in food packaging because it has good mechanical and physical properties. However, the types of plastic used in food packaging, such as polyethylene (PE), polypropylene (PP), and polycarbonate (PC), are petroleum-based plastic that is not renewable, not biodegradable, and causes environmental pollution. One option to overcome this problem is to make bioplastic using renewable sources, one of which is carrageenan. Carrageenan is a polysaccharide used in bioplastic synthesis, but it has shortcomings in terms of mechanical properties. Thereby it needs additional supporting materials to improve its mechanical properties. This study aims to obtain optimal mechanical properties such as tensile strength, elongation, and modulus of elasticity. We optimized two variables in this study: glycerol concentration (1, 2, 3, 4, and 5%) and montmorillonite concentration (10, 20, and 30%). Optimization was carried out in two stages; the first stage was the optimization of glycerol concentrations, and the second stage was the optimization of montmorillonite concentrations. The optimum condition was obtained at 3% (v/v) glycerol and 20% (w/w) montmorillonite which gives a tensile strength value of 3.43 MPa, elongation of 47.01%, and Young Modulus of 7.31 MPa. Based on these optimization results, carrageenan-based bioplastic, especially on %EAB value, are comparable with other commercial plastic for food packaging.

Plastic-Rock Complexes as Hotspots for Microplastic Generation.

Discarded plastics and microplastics (MPs) in the environment are considered emerging contaminants and indicators of the Anthropocene epoch. This study reports the discovery of a new type of plastic material in the environment─plastic-rock complexes─formed when plastic debris irreversibly sorbs onto the parent rock after historical flooding events. These complexes consist of low-density polyethylene (LDPE) or polypropylene (PP) films stuck onto quartz-dominated mineral matrices. These plastic-rock complexes serve as hotspots for MP generation, as evidenced by laboratory wet-dry cycling tests. Over 1.03 × 108 and 1.28 × 108 items·m-2 MPs were generated in a zero-order mode from the LDPE- and PP-rock complexes, respectively, following 10 wet-dry cycles. The speed of MP generation was 4-5 orders of magnitude higher than that in landfills, 2-3 orders of magnitude higher than that in seawater, and >1 order of magnitude higher than that in marine sediment as compared with previously reported data. Results from this investigation provide strong direct evidence of anthropogenic waste entering geological cycles and inducing potential ecological risks that may be exacerbated by climate change conditions such as flooding events. Future research should evaluate this phenomenon regarding ecosystem fluxes, fate, and transport and impacts of plastic pollution.

Determination of Processing Precision of Hole in Industrial Plastic Materials

The precision of the thread processed by tapping is closely related to the precision of the pre-drilling of the blank. Currently, the technologies for processing threads with the tap in the case of metals are well established. In this sense, there are tables and clear recommendations about the tool pairs-helical drill-tap, depending on the size of the thread, but in the case of plastics, no correlations or recommendations have been found. A well-known aspect concerns the fact that the hole made in plastics is obtained with a smaller diameter than the diameter of the drill bit used. To determine the differences between the drill bit and the diameter of the resulting hole, and its precision on different types of plastic materials, experimental research was started. At the same time, the tolerance of the resulting hole was checked and the influence of the cutting regime on the processing precision was studied. During the experiments, plastic materials often used in the aeronautical and car-building industries were used: POM-C, PA6, PEHD1000, Sika Block 700, Sika Block 960, and Sika Block 980. Following the experiments, differences in the diameter of the holes processed were found according to the plastic mass of even 0.3 mm, which is 4.4% of the diameter of the hole. Based on the experimental results and the design of the experiment, recommendations could be made about the diameter of the drill to use to obtain the desired diameter of the hole after processing.

Agricultural Plastic Waste Management

This article aims at describing both the studies and results implemented in the framework of the H2020-EU research project “RECOVER: New bio-recycling routes for food packaging and agricultural plastic waste” which deals with the sustainability of innovative biodegradation processes for plastic waste and production, in any environmental, social, economic and safety matters. In such a framework, the POLOG University Centre (Livorno, Italy), reconstructed and analyzed the actual farm plastic waste supply chain, as described in the following sections. The first section is introductive and it has been intended as a primer to the most common different types of plastic materials. The second section has deserved to be a state of the art on the most relevant issues raised in plastic waste management. The third section deals with suitable approaches to address the environmental side effects of rapidly growing plastics production, use, and disposal. Some of these approaches were listed, such as physical treatment of the polymeric components, plastic reduction use and employment as much as mechanical and/or chemical recycling and energy recovery. The fourth section shows how some of the above main issues, which raise coping with plastic reduction and recycling, are suited to be coped with from a logistics perspective. Such logistics belong to the basic needs due to tackling any plastic waste supply chain, i.e. collection and transport to intermediate stock and final delivery to recycling plants and/or brownfields, applying the set of methodologies and techniques drawn from the well-known field of pick-up-and-delivery models. These last tasks become crucial when the main effort has addressed the enforcement of any feasible changes from the use of items made in old high environmental intrusive to their replacement with new agricultural and biodegradable plastics. The paper goes to end presenting shortly of a few suitable solutions that could be proposed and applied to the entire plastic waste supply chain. Finally, some concrete aspects of each phase of the supply chain were discussed and it was highlighted how much each of these can be best used in addressing the problem known throughout the world as the problem of the emergency of old plastic waste.

Analysis of Fuel Alternative Products Obtained by the Pyrolysis of Diverse Types of Plastic Materials Isolated from a Dumpsite Origin in Pakistan.

The current energy crisis and waste management problems have compelled people to find alternatives to conventional non-renewable fuels and utilize waste to recover energy. Pyrolysis of plastics, which make up a considerable portion of municipal and industrial waste, has emerged as a feasible resolution to both satisfy our energy needs and mitigate the issue of plastic waste. This study was therefore conducted to find a solution for plastic waste management problems, as well as to find an alternative to mitigate the current energy crisis. Pyrolysis of five of the most commonly used plastics, polyethylene terephthalate (PET), high- and low-density polyethylene (HDPE, LDPE), polypropylene (PP), and polystyrene (PS), was executed in a pyrolytic reactor designed utilizing a cylindrical shaped stainless steel container with pressure and temperature gauges and a condenser to cool down the hydrocarbons produced. The liquid products collected were highly flammable and their chemical properties revealed them as fuel alternatives. Among them, the highest yield of fuel conversion (82%) was observed for HDPE followed by PP, PS, LDPE, PS, and PET (61.8%, 58.0%, 50.0%, and 11.0%, respectively). The calorific values of the products, 46.2, 46.2, 45.9, 42.8 and 42.4 MJ/kg for LPDE, PP, HPDE, PS, and PET, respectively, were comparable to those of diesel and gasoline. Spectroscopic and chromatographic analysis proved the presence of alkanes and alkenes with carbon number ranges of C9-C15, C9-C24, C10-C21, C10-C28, and C9-C17 for PP, PET, HDPE, LDPE, and PS, respectively. If implemented, the study will prove to be beneficial and contribute to mitigating the major energy and environmental issues of developing countries, as well as enhance entrepreneurship opportunities by replicating the process at small-scale and industrial levels.

Tensile testing of samples printed on Delta and Cartesian 3D printer

This paper exposes the initial part of a research consisting in the study of the tensile behavior of the 3D parts printed on two type of 3D printers, one Delta model FLSun QQ-S PRO and other one Cartesian model Tevo Tornado, by using three types of plastic materials, PLA, PLA-CF and PET-G. After a short introduction and a literature review on previous studies reffering to the subject, in the experimental section are exposed the printing parameters selected for printing the samples, toghether with the explanation of the testing procedure. The first set of results obtained is presented, consisting in the values achieved for two parameters, the load sustained by the test specimens at yield and at break, some graphic reprezentation of their variation, respectively a short interpretation of the results. Further tests and analysis will be developed in future work, in order to realize a comparative characterization of the 3D printed parts in function by the printers and materials used.

Utilization of Recycled PP-Talc Waste into Composite Products with the Hot Melt Mixing Method

Polypropylene (PP) is one type of plastic material often used. As the materials' specifications get higher, PP is combined with other materials to achieve the desired characteristics. One of them is Talc. Behind its significant growth, there is one main problem, namely the mismanagement of plastic waste that causes environmental pollution. Therefore, one method that can overcome this problem is the recycling method. This research was conducted to investigate the characterization between pure and recycled materials and the optimum composition obtained to get finished goods that were close to materials using pure materials. This research was conducted using PP-Talc scrap with 20% and 30% talc content, then combined with dry and hot melt mixing methods. The alloy material was then tested using a Scanning Electronic Microscope (SEM), Universal Testing Machine (UTM), and Simultaneous Thermal Analyzer (STA). The results showed that the recycled material's morphological changes, mechanical properties, and thermal properties almost resembled the pure material. Specific ratios of 20% and 30% recycled PP-Talc gave rise to new morphological changes and mechanical properties.

Intelligent polarization-sensitive holographic flow-cytometer: Towards specificity in classifying natural and microplastic fibers

Micron size fiber fragments (MFFs), both natural and synthetic, are ubiquitous in our life, especially in textile clothes, being necessary in modern society. In the Earth's aquatic ecosystem, microplastic fibers account for ~91% of microplastic pollution, thus deserving notable attention as one of the most alarming ecological problems. Accurate automatic identification of MFFs discharges in specific upstream locations is highly demanded. Computational microscopy based on Digital Holography (DH) and machine learning has been demonstrated to identify microplastics in respect to microalgae. However, DH is a non-specific optical tool, meaning it cannot distinguish different types of plastic materials. On the other hand, materials-specific assessments are pivotal to establish the environmental impact of different textile products and production processes. Spectroscopic assays can be employed to identify microplastics for their intrinsic specificity, although they are generally low-throughput and require large concentrations to enable effective measurements. Conversely, MFFs are usually finely dispersed within a water sample. Here we rely on a polarization-resolved holographic flow cytometer in a Lab-on-Chip (LoC) platform for analysing MFFs. We demonstrate that two important objectives can be achieved, i.e. adding material specificity through polarization analysis while operating in a microfluidic stream modality. Through a machine learning numerical pipeline, natural fibers (i.e. cotton and wool) can be clearly separated from synthetic microfilaments, namely PA6, PA6.6, PET, PP. Moreover, the proposed system can accurately distinguish between different polymers under investigation, thus fulfilling the specificity goal. We extract and select different features from amplitude, phase and birefringence maps retrieved from the digital holograms. These are shown to typify MFFs without the need for sample pre-treatment or large concentrations. The simplicity of the DH method for identifying MFFs in LoC-based flow cytometers could promote the use of polarization resolved field-portable analysis systems suitable for studying pollution caused by washing processes of synthetic textiles.

Experimental analysis on shredder for recycling thermoplastics using injection moulder

The current work mainly focused on analyzing the performance of plastic crushers designed and fabricated as an alternative to traditional impact crushers. The operating mechanism of the injection molding machine combined with the shredder consists of two phases: cutting the plastic using a double-edged blade, then loading the shredded plastic into the hopper and pressing it against the desired mold. For a safer design, the blades were designed based on PET materials as they have higher tensile strength (61.61 MPa) compared to other plastic materials. The time required to shred the plastic was directly proportional to the thickness of the plastic material and the type of plastic material used. For polyethylene terephthalate (PET) with thicknesses of 0.25 mm and 1.5 mm, the cutting time required for the shredder was found to be 11 s and 21 s, respectively. The calculated shear force and shaft torque per blade appeared to be 7.22 N and 108.3 Nm, respectively. It was observed that the torque required to cut the plastic with this shredder was lower than that of the impact crusher. As a result, the overall mechanical complexity and cost of grinding are reduced.

A method to remove cellulose from rich organic samples to analyse microplastics

Knowing the amount of microplastics that currently reach wastewater is extremely important today. Furthermore, carrying out a good quantification and detection of the type of plastic provides valuable information. However, the wastewater is loaded, in addition to a high concentration of organic matter, with a high concentration of cellulose at the treatment plant influent, which seriously hinders detection, quantification and classification of microplastics. The abundance of cellulose materials makes them possible to become false positives for microplastics. Numerous studies on the analysis of microplastics in different matrices show how to remove organic matter from samples, but there are very few studies on the removal of cellulose, which is also found in the samples and hinders their analysis. This study offers a method that combines, for the analysis of microplastics, the already known advanced oxidation treatments for the elimination of organic matter with the novel cellulose removal treatment of the samples with the aim of reducing the amount of cellulose in the influent samples of conventional wastewater treatment plants. To remove the cellulose, 40 mL of a solution of urea 8%, sodium hydroxide 8% and thiourea 6.5% (by weight) were added for every 100 mg of dry sample. The beakers were placed in the freezer at minus 20 °C for 40 min and were then placed in agitation until they reached room temperature. After that, the samples were passed through a 53 μm mesh sieve. They were washed 15 times with 30 mL of ultra-pure water. The method is called UTS because of the acronym of its reagents (Urea/Thiourea/Sodium Hydroxide). By using the UTS method it is possible to reduce almost completely the cellulose residues from the influent sewage, and sludge samples by 97.6% in a second UTS treatment and 98.2% in a third UTS treatment. In all cases analyzed, the microplastics were identified as high density polyethylene (HDPE) with correlation indices higher than 0.97, which shows that the treatment is harmless for this type of plastic material. The UTS method in combination with the WPO is an efficient and effective method for the analysis of microplastics in different matrices where cellulose and organic matter may cause possible interferences.

Chemical, Thermal, and Rheological Performance of Asphalt Binder Containing Plastic Waste

In order to meet the environmental needs caused by large plastic waste accumulation, in the road construction sector, an effort is being made to integrate plastic waste with the function of polymer into asphalt mixtures; with the purpose of improving the mechanical performance of the pavement layers. This study focuses on the effect of a recycled mixture of plastic waste on the chemical, thermal, and rheological properties of designed asphalt blends and on the identification of the most suitable composition blend to be proposed for making asphalt mixture through a dry modification method. Thermo-gravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy analysis were carried out to investigate the effect of various concentrations and dimensions of plastic waste (PW) on the neat binder (NB). The frequency sweep test and the multiple stress creep and recovery test were performed to analyze the viscoelastic behavior of the asphalt blends made up of PW in comparison with NB and a commercial modified bitumen (MB). It has been observed that the presence of various types of plastic materials having different melting temperatures does not allow a total melting of PW powder at the mixing temperatures. However, the addition of PW in the asphalt blend significantly improved the aging resistance without affecting the oxidation process of the plastic compound present in the asphalt blend. Furthermore, when the asphalt blend mixed with 20% PW by the weight of bitumen is adopted into the asphalt mixture as polymer, it improves the elasticity and strengthens the mixture better than the mixture containing MB.

Data-Driven Recyclability Classification of Plastic Waste

This work aims to propose a general data-driven plastic waste categorisation procedure that defines their recyclability based on classification into material recycling classes. The contamination in plastics, such as metal fillers or additives, is accumulated during the entire Life Cycle, which can be harmful to either mechanical or chemical recycling. The plastic polymers can also degrade during recycling due to weakened chemical bonds in the polymers. The diversity of plastic material types and products makes it necessary to use a data-driven quality-based definition of plastic waste properties to facilitate proper waste recycling and mitigation. This study demonstrates the use of Machine Learning tools that enable automated classification to analyse the plastic waste data and derive the indicators for plastic waste recyclability. Tree-based models such as the Decision Tree Model and Random Forest Algorithm are used as they produce interpretable if-then rules for plastic waste categorisation. The proposed method allows an analysis of the metal contamination and degradation data in a collection of plastic material samples or batches to derive a general categorisation rule for a polymer type – PE. The data-driven plastic categorisation could help in understanding the current waste practices and determining a proper recycling plan for local or even global plastic waste.