PVC Particles Research Articles

Measuring Microplastic Concentrations in Water by Electrical Impedance Spectroscopy

Plastics are vital for society, but their usage has grown exponentially and contributes to the growth of pollution worldwide. The World Health Organization, WHO, already reported that microplastics (MPs) are found everywhere, in waste and fresh water, and in the air and soil. Regarding water effluents, waste-water treatment plants only minimize the problem, trapping only larger size particles. In contrast, smaller ones remain in oxidation ponds or sewage sludges, or are even released to aquifers environment. Classic procedures for MPs detection are still quite laborious, and are usually conducted off-line, involving several steps and expensive equipment. Electrical Impedance Spectroscopy, EIS, is a technique that allows the analysis of a system’s electrical response, yielding helpful information about its domain-dependent on physical-chemical properties. Due to the superficial electronegativity of MPs’ particles, EIS may allow to attain the purpose of the present work: to provide a fast and reliable method to detect/estimate MPs’ concentration in water effluents. Among the most common microplastics are Polyethylene, PE, and Polyvinyl Chloride, PVC. Using the developed setup and experimental data collection methodology, the authors could differentiate between MPs’ suspensions containing the same concentration of the different evaluated MPs, PVC and PE, and assess PVC concentration variation, in the interval between 0.03 to 0.5 g (w/w), with an error, estimated based on the obtained impedance modulus, around or below 3% for the entire stimulus signal frequency range (from 100 Hz to 40 MHz) for the PVC particles.

One Reaction: Two Types of Mechanism-SARA-ATRP and SET-LRP-for MMA Polymerization in the Presence of PVC.

This study presents for the first time the polymerization of methyl methacrylate (MMA) in the presence of poly(vinyl chloride) (PVC) that takes place by both SARA-ATRP and SET-LRP mechanisms. The two types of polymerizations that occur in the system are PMMA grafting to the PVC backbone and the formation of a new PMMA polymer, both occurring in the presence of a Cu0wire. The polymerizations were controlled as confirmed by the molecular weight evolution, polymerization kinetics, and variations in the dispersity value. The MMA polymerization in the presence of PVC at 60 and 70 °C leads to the formation of two polymer species characterized by an increase in the molecular weight with the conversion and a narrowing of the dispersity value with the reaction progress. To increase the degree of control over the polymerization, the same reaction was performed at room temperature, which allowed us to highlight the presence of the SARA-ATRP and SET-LRP mechanisms via subsequent polymer chain extensions. The results demonstrated that PMMA grafting on PVC polymers follows a SARA-ATRP mechanism, while the formation of a PMMA homopolymer entails a SET-LRP process. The influence of solvent nature on the polymerization reaction was studied by performing the grafting of N-isopropylacrylamide (NIPAM) onto the surface of PVC particles in aqueous media in the presence and in the absence of CuCl2. The polymerization reactions and the obtained materials were studied by gel permeation chromatography (GPC), 1H NMR, DMA, scanning electron microscopy (SEM), and atomic force microscopy (AFM).

Reusability of Scrap Rubber, Tire Shredding, Recycled PVC and Fly Ash for Development of Composites with Vibration Damping Ability.

The study focuses on harnessing recycled materials to create sustainable and efficient composites, addressing both environmental issues related to waste management and industrial requirements for materials with improved vibration damping properties. The research involves the analysis of the physico-mechanical properties of the obtained composites and the evaluation of their performance in practical applications. Composite materials were tested in terms of their tensile strength and vibration damping capabilities, considering stress-strain diagrams, vibration amplitudes, frequency response functions (FRFs) and vibration modes. The research results have shown that by adding PVC and FA to the rubber-based matrix composition, the stiffness decreases and elasticity increases. The use of FA in the structure of composite materials causes an increase in the vibration damping possibilities due to the fact that it contributes to the chemical properties of the analyzed composite materials. Additionally, the use of PVC results in increased material elasticity, as evidenced by the higher damping factor compared to materials containing only rubber. Simultaneously, the addition of FA and PVC in specific proportions (60 phr) can lead to a decrease in stiffness and a greater increase in the damping factor. The incorporation of PVC and fly ash (FA) particles into rubber-based matrix composites reduces their stiffness and increases their elasticity. These effects are due to the fact that FA particles behave as extensions of chemical bonds during traction, which contributes to the increase in yield elongation. In addition, the use of flexible PVC increases the elasticity of the material, which is evidenced by the increase in the damping factor.

Investigation of the fabric effect on the arching effect in granular materials

A series of trapdoor experiments and DEM simulations were carried out in this study to examine the arching effect in granular materials, with the focus being on the influence of the direction for particle deposition. In the tests, particles (e.g. rice grains, PVC particles and nylon particles) were dropped as if they were raining at different directions to construct granular material layers with various fabric orientations. It is shown that the mobilization of arching effect depends on the direction of particle deposition, with the arching ratio ρ increasing at first and then decreasing. The arching effect is the weakest at a deposition angle of θ = 30° in obliquely deposited granular masses. It is also found that the vertical displacement of particles in the ultimate phase increases initially; it then decreases with the variation in the orientation of particle deposition, and the largest displacement occurs at θ = 30°.

Recycled PVC content and particle size distribution effects on morphological and mechanical properties of expanded PVC layer for floorcoverings

Recycled PVC content and particle size distribution effects on morphological and mechanical properties of expanded PVC layer for floorcoverings

Impact of Microplastic on Freshwater Sediment Biogeochemistry and Microbial Communities Is Polymer Specific

Plastic debris is a growing threat in freshwater ecosystems and transport models predict that many plastics will sink to the benthos. Among the most common plastics found in the Laurentian Great Lakes sediments are polyethylene terephthalate (especially fibers; PET), polyvinylchloride (particles; PVC), and styrene-butadiene rubber resulting from tire wear (“crumb rubber”; SBR). These materials vary substantially in physical and chemical properties, and their impacts on benthic biogeochemistry and microbial community structure and function are largely unknown. We used a microcosm approach to evaluate the impact of these three plastics on benthic-pelagic coupling, sediment properties, and sediment microbial community structure and function using sediments from Irondequoit Bay, a major embayment of Lake Ontario in Rochester, New York, USA. Benthic metabolism and nitrogen and phosphorous cycling were all uniquely impacted by the different polymers. PET fibers and PVC particles demonstrated the most unique effects, with decreased ecosystem metabolism in sediments containing PET and greater nutrient uptake in sediments with PVC. Microbial diversity was reduced in all treatments containing plastic, but SBR had the most substantial impact on microbial community function, increasing the relative importance of metabolic pathways such as hydrocarbon degradation and sulfur metabolism. Our results suggest that individual polymers have unique impacts on the benthos, with divergent implications for ecosystem function. This provides deeper insight into the myriad ways plastic pollution may impact aquatic ecosystems and will help to inform risk assessment and policy interventions by highlighting which materials pose the greatest risk.

An experimental study of triboelectrostatic particle charging behavior and its associated fundamentals

Triboelectrostatic separation is a unique dry particle separation process that has been applied to many industrial applications. However, little attention has been directed to the process of charge transfer during the particle collision and friction which is critical for the success of triboelectrostatic separation. The present study has been conducted to quantify the effects of particle size, collision speed, contact mode (collision or friction), etc. on the charge density, surface potential, morphology, etc. of quartz particles based on macroscopic triboelectrostatic charge measurements and microscopic atomic force microscopy (AFM) characterization. The macroscopic charging performance results showed that the charge to mass ratio of quartz particles depended on process parameters such as feed rate and charger rotation speed and the highest charge to mass ratio reached −56.21 μC/g. The microscopic AFM characterization data reveals that the increase in particle size and collision velocity fundamentally enhanced the triboelectrostatic charging process. The surface potential of quartz increased from −60.60 mV to −477.15 mV with increasing PVC particle size from 280 μm to 1250 μm and similar behavior was observed with increasing the collision velocity from 0.99 m/s to 2.62 m/s. The change in contact mode only changed the magnitude of charge transfer but did not change the polarity of charged particle. The process of charge transfer was accompanied with the change of surface morphology and the degree of change in surface morphology was not directly related to the amount of charge transfer.

In situ suspension polymerization of vinyl chloride/3-(trimethoxysilyl) propyl methacrylate (MPTMS) intercalated Mg-Al-layered double hydroxide: II. Morphological, thermal properties and diffusion behavior

A series of PVC composites were produced using an in-situ suspension polymerization method with an optimal amount of 5 wt% of MgAl(NO3) layered double hydroxide (LDH) or LDH-MPTMS, which is MPTMS-intercalated Mg-Al LDH. The physical, mechanical, and thermal properties of the composite samples were compared to pure PVC. Results from the Brabender® plastograph showed that the PVC grains produced with LDH-MPTMS had a longer thermal stability time and shorter fusion time. The addition of LDH-MPTMS nanosheets increased the gelation degree of PVC particles, resulting in a lower temperature/time requirement for processing. The thermal stability of the composite material was confirmed through a standard dehydrochlorination test, which demonstrated a 40% improvement in dehydrochlorination rate compared to pure PVC. This improvement was 12% higher than that observed in the PVC/LDH composite. TGA curves indicated a significant increase in the 5 and 50% weight loss temperatures of PVC resins with the addition of 5wt% LDH or LDH-MPTMS, with an approximate growth of 11°C. The glassy state storage modulus and Tg of the PVC/LDH-MPTMS composite were higher than those of pure PVC and the PVC/LDH composite. Mechanical analysis revealed that the PVC/LDH-MPTMS composites exhibited greater stiffness and toughness, as well as significantly higher Charpy notched impact strength, tensile strength, and Young’s modulus compared to both the PVC/LDH composite and pure PVC.

Study and analysis of strength parameters of concrete with the addition of stone dust, PVC, and fibres

The strength parameters of cement can be upgraded through the expansion of different materials like “stone dust, PVC, and fibers”. “Stone dust”, a side-effect of stone pulverizing tasks, can be utilized as a fractional substitution for fine total in concrete. It works on the functionality, toughness, and compressive strength of cement. PVC particles can be integrated in with the general mish-mash to improve the flexural and influence strength of cement. The incorporation of fibers, like steel or polypropylene, works on the elastic and flexural strength of cement, “lessening breaking and expanding protection” from dynamic burdens. This abstract investigates the impacts of these added substances on substantial “strength parameters, featuring” their expected advantages in development applications.

Leaching of Dibutyltin from Virgin Polyvinyl Chloride Pipe Material

This study examined the leaching of dibutyltin (DBT) from PVC particles derived from three different types of PVC pipes. Leaching of DBT into artificial freshwater was investigated at pH 6, 7, and 8, using both small (45–125 μm) and large (300–500 μm) particles alone, as well as in the presence of chlorine or chloramine to represent typical secondary disinfectants used in drinking water. Aqueous DBT concentration varied among the three pipes, suggesting that specific PVC formulations may be more amenable to leaching than others. An increase in pH from 6 to 8 was associated with higher DBT concentrations (by up to 100%), and a greater impact was observed for smaller sized particles. The presence of chlorine increased residual DBT by up to 25%, whereas chloramine exhibited a negligible impact. As treated drinking water commonly has a pH of 7–8 and PVC pipe is increasingly being employed for distribution, these findings highlight the need to assess the leaching of DBT under representative conditions.

Evaluation of fracture behavior of stone mastic asphalt (SMA) containing recycled materials under different loading modes at low temperatures

Using natural materials (including aggregates and bitumen) in the asphalt paving industry causes significant and irreparable damage to the environment annually. Utilizing waste materials in producing asphalt pavements can be a suitable solution to reduce such damages. Therefore, this paper studied the impacts of recycled crumb rubber (CR), recycled PVC particles, and reclaimed asphalt pavement (RAP) in different percentages on the performance of stone mastic asphalt (SMA) mixture against low-temperature cracking. PVC and CR additives were added to asphalt mix in two wet and dry methods. Thermal cracks are important and common failures of asphaltic pavements, and considerable financial budgets are allocated annually in different countries to deal with these damages. In this investigation, the fracture toughness of 16 various asphalt mixes at three distinct temperatures (temperatures of zero, −10, and −20° C) and under three diverse loading modes (including the mixed-mode I/ II, the pure mode II, and the pure mode I), were investigated by Semi-circular bending (SCB) fracture test. In addition to laboratory reports and mechanical studies, life cycle assessment (LCA) was utilized in this research to estimate and compare the influence of these asphalt mixes on the environment. The outcomes of mechanical tests and environmental analysis demonstrated that the usage of waste materials in this study has significantly enhanced the fracture strength of the SMA mix against low-temperature cracks and reduced its negative environmental effects. Therefore, the mixture containing RAP and 20% recycled PVC had the most satisfactory performance both in terms of environmental and fracture performance.

Physical and Mechanical Properties of Cementitious PVC Composites

This research studies the physical and mechanical properties of mortar composed of PVC plastic waste particles used as fine aggregate replacement material. PVC particles in quantities of 5%, 10%, 15%, 20%, 25%, and 30% by volume were used for sand fraction substitution. This quantity of PVC was used to formulate seven mixes with a cement content of 525 kg/m3 and a water-to-cement ratio (w/c) of 0.45. At 7 and 28 days, the compressive and splitting tensile strengths of the mortar's mechanical characteristics were evaluated. Additionally, the physical characteristics of density and absorption were investigated. The findings demonstrated that the mechanical properties and density of mortar containing PVC powder were minimized.

Soft and Rigid Integrated Durable Coating for Large-Scale Deicing

Soft silicone has been widely used for anti-icing coating, but the ice adhesion strength is usually scaled with the iced area at a relatively large thickness. On the other hand, a thin rigid poly(vinyl chloride) (PVC) film could be independent of the iced area and was named a low-interfacial-toughness material. Thus, a soft and rigid integrated (SRI) coating was prepared by doping PVC particles into a silicone matrix here. The introduction of PVC particles not only served as phase II to accelerate the stress concentration but also favored the formation of a wrinkle structure. After further introducing plasticizers, this SRI coating not only has a very low ice adhesion strength at a low iced length but also tends to a limit value irrespective of the iced length, which further leads to excellent large-area deicing behavior. Furthermore, the SRI coating demonstrated outstanding chemical stability, mechanical robustness, and on-field repairability.

Thermal recycling strategy of Coca-Cola PVC label films by its co-carbonization with Terminalia ivorensis leaves

The Coca-Cola company utilizes PVC label films for its product packaging, which may be due to their high physicochemical durability. However, these films are less recycled in comparison with other plastics due to their release of chlorine-based chemicals, leading to environmental pollution on a global scale. In this study, Coca-Cola PVC label films were co-carbonized with Terminalia ivorensis leaves (TIL) in a top-lit updraft reactor to produce biochar. The properties of the PVC-impregnated biochar (TIL-PVC-biochar) were compared with those of the leaves (TIL-biochar), using SEM-EDX, FTIR, BET analysis, and DTA/TGA to study the effect of the PVC on the material. The carbonization process, which ran for duration of 100 minutes, gave a yield of 42.50% and 45.60% for TIL-biochar and TIL-PVC-biochar, respectively. The EDX result confirmed the success of the impregnation process with an increased concentration of carbon and chlorine in TIL-PVC-biochar. The SEM result indicates the presence of good interfacial bonding around the thermo-chemically disintegrated PVC particles. BET analysis showed that PVC impregnation reduced the surface and pore properties of the biochar. TIL-PVC-biochar had a BET surface area and a pore diameter of 194 m 2 /g and 2.088 nm, respectively. FTIR analysis showed TIL-PVC-biochar contained functional groups such as hydroxyl, carbonyl, carboxylic, alkene, and alkyne groups. It also confirmed the presence of chlorine. DTA/TGA showed that TIL-PVC-biochar was more thermally stable than TIL-biochar. The properties of TIL-PVC-biochar make it a good material for the production of conductive composites and an adsorbent for the sequestration of pollutants from the environment.

Comparison of pre-treatment methods and heavy density liquids to optimize microplastic extraction from natural marine sediments

The ubiquitous occurrence of anthropogenic particles, including microplastics in the marine environment, has, over the last years, gained worldwide attention. As a result, many methods have been developed to estimate the amount and type of microplastics in the marine environment. However, there are still no standardized protocols for how different marine matrices should be sampled or how to extract and identify these particles, making meaningful data comparison hard. Buoyant microplastics are influenced by winds and currents, and concentrations could hence be expected to be highly variable over time. However, since both high density and most of the initially buoyant microplastics are known to eventually sink and settle on the seafloor, marine sediments are proposed as a suitable matrix for microplastics monitoring. Several principles, apparatuses, and protocols for extracting microplastics from marine sediments have been presented, but extensive comparison of the different steps in the protocols using real environmental samples is lacking. Thus, in this study, different pre-treatment and subsequent density separation protocols for extraction of microplastics from replicate samples of marine sediment were compared. Two pre-treatment methods, one using inorganic chemicals (NaClO + KOH + Na4P2O7) and one using porcine pancreatic enzymes, as well as one with no pre-treatment of the sediment, were compared in combination with two commonly used high-density saline solutions used for density separation, sodium chloride (NaCl) and zinc chloride (ZnCl2). Both pre-treatment methods effectively removed organic matter, and both saline solutions extracted lighter plastic particles such as polyethylene (PE) and polypropylene (PP). The most efficient combination, chemical pre-treatment and density separation with ZnCl2, was found to extract > 15 times more particles (≥ 100 µm) from the sediment than other treatment combinations, which could largely be explained by the high presence and efficient extraction of PVC particles.

Method of manufacturing and staining microplastics for using in the biological experiments.

Nowadays, plastic pollution attracts much attention both from society and scientists. The plastic pollution impact on the environment and human health requires assessment urgently, especially through experimental studies. However, such studies are still scarce because of the lack of standard methods for assessing their effects on living organisms. We have developed a process for manufacturing and staining PVC microparticles for using them in biological and ecological experiments. The electrospinning method has been used to manufacture PVC particles; their morphology and size have been analyzed. The obtained PVC particles are of narrow size range averaging 2-4µm in diameter. They are successfully stained with the fluorescent dye Rhodamine B, which stands for the experiments performed in the seawater.

Systematic study on fabrication of hollow poly(vinyl cinnamate) particles by particulate interfacial photocrosslinking

AbstractHollow polymer particles are widely used in various industries as coatings and thermal insulation materials. The encapsulation capabilities of various functional molecules and/or nanomaterials also provide access to applications such as drug delivery, heat storage, and catalysis, as well as self‐healing materials. In this study, we successfully fabricated hollow polymer particles from poly(vinyl cinnamate) (PVC) particles using LED light (λ = 265 nm) through interfacial photocrosslinking. Furthermore, we systematically studied the effect of various parameters (solid contents of parent particles, photoirradiation time, photoirradiation power, and polymer chain length) on the polymer shell thickness of the hollow PVC particles fabricated by interfacial photocrosslinking. These findings are expected to further promote the use of hollow polymer particles in pharmaceutical and material applications.

Mechanical Properties of Concrete Contained Recycled PVC Additives

This research is studied the possibility of reusing PVC pipes wastes as partial replacement of sand within concrete mixture. In this study, the fine aggregate is replaced with PVC at dosages 1.25%, 2.5%, 3.75% and 5% by weight of sand with superplasticizer (SP) admixture. The mechanical properties are evaluated, which included compressive strength, splitting tensile strength, and flexural strength, in which for each one, 60 specimens are tested for water to cement ratios 0.41 and 0.53. Also, the effect of these wastes on the strengths and serviceability of concrete beams are investigated by testing three simply supported reinforced concrete beams of dimensions 150×200×1400 mm. It is concluded that w/c ratio of 41% of the replacement of fine aggregates with 1.25% PVC particles showed the optimum results for compressive, tensile and flexural strengths, namely 31.66 %, 6.45%, and 31.23%, respectively, more than control mixture. The beam specimen that contain on 1.25% of PVC particles showed an increase in ultimate load by about 6.06% compared to the reference beam. While the hybrid cross section beam showed a relatively small reduction in ultimate load compared to reference beam, i.e, 14.5%. Thus with hybrid sections considerable amount of plastic wastes could be recycled with relatively small reduction in ultimate capacity of beams.

Nanoplastics affect the inflammatory cytokine release by primary human monocytes and dendritic cells

So far, the human health impacts of nano- and microplastics are poorly understood. Thus, we investigated whether nanoplastics exposure induces inflammatory processes in primary human monocytes and monocyte-derived dendritic cells. We exposed these cells in vitro to nanoplastics of different shapes (irregular vs. spherical), sizes (50–310 nm and polydisperse mixtures) and polymer types (polystyrene; polymethyl methacrylate; polyvinyl chloride, PVC) using concentrations of 30–300 particles cell−1. Our results show that irregular PVC particles induce the strongest cytokine release of these nanoplastics. Irregular polystyrene triggered a significantly higher pro-inflammatory response compared to spherical nanoplastics. The contribution of chemicals leaching from the particles was minor. The effects were concentration-dependent but varied markedly between cell donors. We conclude that nanoplastics exposure can provoke human immune cells to secrete cytokines as key initiators of inflammation. This response is specific to certain polymers (PVC) and particle shapes (fragments). Accordingly, nanoplastics cannot be considered one homogenous entity when assessing their health implications and the use of spherical polystyrene nanoplastics may underestimate their inflammatory effects.

Piezoelectric Disinfection of Water Co-Polluted by Bacteria and Microplastics Energized by Water Flow

The presence of microplastics in the aquatic environment, as a vector for colonization and proliferation of harmful microorganisms, brings a great challenge for water disinfection. This study investigates piezoelectric inactivation of Gram-negative bacteria Escherichia coli (E. coli) and Gram-positive bacteria Enterococcus faecalis (E. faecalis) on the surface of microplastics under water flow by using molybdenum disulfide as piezoelectric material. The piezoelectric sterilization capacity was evaluated by comparing different polymer types and sizes of microplastics, in which 4.5 log10 CFU mL–1 E. coli cells were reduced for 50 μm PVC particles at a water flow speed of 80 rpm in 20 min. Piezoelectric disinfection was dependent on water flow rates and treatment time and was feasible in riverine water containing authentic microplastics and in a spiral reactor that simulated natural water flow. Reactive oxygen species were generated via water flowing over the piezoelectric material, resulting in the inactivation of bacteria on the surface of microplastics. This study highlighted the great potential of water flow as a “green” source of energy and elucidated a new opportunity of piezoelectric disinfection in aqueous media containing microplastics.