Polystyrene Products Research Articles

Biodegradation of polystyrene and polyethylene by Microbacterium esteraromaticum SW3 isolated from soil

Plastic pollution is a common concern of global environmental pollution. Polystyrene (PS) and polyethylene (PE) account for almost one-third of global plastic production. However, so far, there have been few reports on microbial strains capable of simultaneously degrading PS and PE. In this study, Microbacterium esteraromaticum SW3, a non-pathogenic microorganism that can use PS or PE as the only carbon source in the mineral salt medium (MM), was isolated from plastics-contaminated soil and identified. The optimal growth conditions for SW3 in MM were 2% (w/v) PS or 2% (w/v) PE, 35°C and pH 6.3. A large number of bacteria and obvious damaged areas were observed on the surface of PS and PE products after inoculated with SW3 for 21 d. The degradation rates of PS and PE by SW3 (21d) were 13.17% and 5.39%, respectively. Manganese peroxidase and lipase were involved in PS and PE degradation by SW3. Through Fourier infrared spectroscopy detection, different functional groups such as carbonyl, hydroxyl and amidogen groups were produced during the degradation of PS and PE by SW3. Moreover, PS and PE were degraded into alkanes, ketones, carboxylic acids, esters and so on detected by GC-MS. Collectively, we have isolated and identified SW3, which can use PS or PE as the only carbon source in MM as well as degrade PS and PE products. This study not only provides a competitive candidate strain with broad biodegradability for the biodegradation of PS and/or PE pollution, but also provides new insights for the study of plastic biodegradation pathways.

FeCl3-Catalyzed Aerobic Oxidative Degradation of Polystyrene to Benzoic Acid: Scope and Mechanism

AbstractChemical upcycling of polystyrene (PS) is one of the most promising approaches to plastic waste reuse and to achieve economic development goals. However, it remains a huge challenge because PS has only chemically inert covalent bonds. As part of an ongoing study, we herein describe the development, scope, and mechanism of photoinduced iron catalysis for the selective oxidative degradation of polystyrene to benzoic acid. A series of commonly found polystyrene products could be degraded to benzoic acid efficiently. A plausible mechanism involving radical-based stepwise aerobic oxidation was proposed.

The Characterization of Mechanical and Chemical Properties of Recycled Styrofoam Waste Employing Extrusion Process

<p><em>Styrofoam waste is a polystyrene plastic-based waste in the form of foam with low density. Scavengers or recyclers are not interested in receiving styrofoam waste because of its light density which makes it ineffective in transportation and storage. Styrofoam waste can actually be converted into solid polystyrene products through a thermal-extrusion process but data regarding the optimum operating temperature and the characteristics of the resulting solid polystyrene products are not yet available. The purpose of this study was to investigate the properties of solid polystyrene products resulting from recycled styrofoam waste and determine the optimum temperature of the thermal-extrusion treatment process to be compared with the characteristics of the original polystyrene based on the results of tensile and impact tests. In this study, the processing was carried out using the thermal-extrusion method; Styrofoam is melted and extruded into a mold to produce polystyrene solids. The research was carried out with variations in extrusion temperature at 180°C, 200°C, and 220°C. The polystyrene solids are then molded into tensile and impact test specimens by injection molding. The results showed that the optimal extrusion temperature was 200°C with tensile and impact strength values of 27.55 MPa and 1,069 j/m2, respectively. Compared to the original polystyrene, the tensile strength value is 25.3% lower and the impact strength value is 29.5% lower. The decrease in the tensile and impact strength values is due to the shortening of the molecular bonds in the recycled polystyrene during the thermal-extrusion treatment process. Even though the tensile strength and impact are still lower, the use of styrofoam waste using the thermal-extrusion method has the potential to be developed at the production and commercialization stage because the resulting product has good economic value and can also reduce the use of original polystyrene and at the same time can solve the problem of styrofoam waste.</em></p>

Polystyrene nanoplastics in the marine mussel Mytilus galloprovincialis.

Concerns about plastic pollution and its toxicity towards animals and people are growing. Polystyrene (PS) is a plastic polymer highly produced in Europe for packaging purposes and building insulation amongst others. Whatever their source—illegal dumping, improper waste management, or a lack of treatment for the removal of plastic debris from wastewater treatment plants—PS products ultimately end up in the marine environment. Nanoplastics (<1000 nm) are the new focus for plastic pollution, gaining broad interest. Whether primary or secondary, their small size permits nanoparticles to cross cellular boundaries, consequently leading to adverse toxic effects. An in vitro assay of Mytilus galloprovincialis haemocytes exposed to 10 μg/L of polystyrene nanoplastics (PS-NPs; 50 nm) for 24 h was used to test cellular viability along with the luminescence inhibition (LC50) of Aliivibrio fischeri bacteria to evaluate acute toxicity. Cellular viability of mussel haemocytes decreased significantly after a 24 h exposure and PS-NPs LC50 range from 180 to 217, μg/L. In addition, a 28-day exposure of the marine bivalve M. galloprovincialis to PS-NPs (10 μg/L; 50 nm) was performed to evaluate the neurotoxic effects and the uptake of these plastic particles in three bivalve tissues (gills, digestive gland, and gonads). The ingestion of PS-NPs was time- and tissue-specific, suggesting that PS-NPs are ingested through the gills and then translocated through the mussel bloodstream, to the digestive gland and gonads where the highest amount of ingested PS-NPs was reported. Ingested PS-NPs may compromise the digestive glands' key metabolic function and impair mussels' gametogenic and reproductive success. Data on acetylcholinesterase inhibition and those previously obtained on a wide range of cellular biomarkers were elaborated through weighted criteria providing a synthetic assessment of cellular hazard from PS-NPs.

Superacid-Assisted Degradation of Polystyrene

We report the degradation pathway of polystyrene in a low-temperature environment by superacid. Polystyrene is a thermoplastic resin widely used in packaging, disposable products, and structural materials. However, economically viable upcycling of polystyrene has yet to be established because of the high cost of chemical recycling and the low value of products. To understand the degradation pathway of polystyrene and establish competitive upcycling practices, we investigated the transformation of normal and deuterated polystyrene chains into small compounds by triflic acid at 20 °C. The degradation study of deuterated polystyrene showed the high stability of the hydrogens at the α carbons of polymerized styrene against triflic acid, which suggests the known β-scission degradation pathway of polystyrene by α-proton abstraction is unlikely. Rather, the polystyrene degradation proceeds through three distinct stages: (i) intrachain cross-linking that forms polymer nanoparticles and simultaneous transformation of polymerized styrene to indan units, (ii) degradation of the polymer nanoparticles into small molecular weight compounds, and (iii) formation of polycyclic aromatic hydrocarbons. The stepwise degradation pathway of polystyrene we report may enable the design of efficient and profitable upcycling processes for end-of-life polystyrene products in low-temperature environments.

Generation of polystyrene-specific antibodies for developing immunoassays to analyze microplastics and nanoplastics

Micro- and nano-plastics (MNPs) are emerging pollutants that have drawn worldwide attention due to their negative impacts on the health and sustainability of our ecosystem. Quantitative analysis of MNPs, especially those at nano-scale, is still challenging due to lack of efficient analytical methods. Different antibody-based immunoassay platforms have been well established and readily available for rapid, specific, and quantitative analysis of targets with a broad size range. The key to developing immunoassays for MNP analysis is to generate plastic-specific antibodies, which is still lacking. In this study, we conjugated the nanoparticles of polystyrene (PS), a widely studied representative MNPs, to different carrier proteins for rabbit immunizations. The PS-specific antibodies were significantly induced upon immunization (up to 128-fold increase in IgG titer), which was validated by multi-tier immunoassays using different PS products. Notably, the PS-specific antibodies did not react with polypropylene, a different plastic. Using PS antibody-based enzyme-linked immunoassay, we further demonstrated suitability of the antibody-based immunoassay for quantitative analysis of the PS particles that have been exposed to diverse matrices. Together, this study, for the first time, demonstrates the feasibility of producing plastic-specific antibodies, and lays the groundwork to develop innovative antibody-based immunoassays for future risk assessment and management of MNPs, particularly those at nano-scale.

Fuel oil production from thermal decomposition of the model and waste polystyrene: Comparative kinetics and product distribution

The thermal degradation of model polystyrene (MPS) and waste polystyrene (WPS) was performed in a thermobalance system at four heating rates (β) i.e., 5, 10, 15 and 20 °C/min in an inert atmosphere. The apparent activation energy (Ea) and frequency factor (A) for the MPS and the WPS were calculated using Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and Augis-Bennetis (AB) methods. It has been determined that Ea and A vary according to fraction conversion, heating rates, and applied models. The activation energy determined for MPS was found to be in the range of 91-106, 90-105, and 114-133 kJ/mol, while, for WPS, Ea was determined in the range of 82-160, 79-159 and 102-202 kJ/mol by applying OFW, KAS, and AB models, respectively. From the results obtained, it was concluded that the Ea determined by all of these methods increases with fraction conversion, indicating that the decomposition of polystyrene follows a complex mechanism of the solid-state reaction. Hence, the kinetic parameters, i.e., Ea and A, seem to play a key role in investigating the mechanism of solid-state reactions and will provide an opportunity to develop the mechanism of the industrial decomposition reactions. The results show that the MPS has a lower activation energy compared to WPS. This high Ea of WPS may be due to the additives used in the manufacturing of different polystyrene products. Pyrolysis GC/MS of WPS indicates that the main components of pyrolysis oil are 1-hydroxy-2-propanone, styrene, α-methyl styrene, toluene, and 1,2-dimethyl benzene. The presence of some oxygenated compounds in the fuel oil of WPS may be due to contamination or additives used during polystyrene processing, as the WPS samples were collected from a garbage dump near a local market. WPS can be utilized as fuel if the fuel oil collected from the pyrolysis of WPS is properly upgraded to make it equivalent to commercial fuel oil.

Toward efficient functionalization of polystyrene backbone through ketene chemistry: Synthesis, characterization, and DFT study

AbstractIn this study, polystyrene was functionalized with Meldrum's acid toward the introduction of the ketenes (CCO) system to its backbone for producing a dramatically reactive intermediate. Meldrum's acid, as a ketene source, was reacted by poly(styrene‐co‐p‐chloromethyl styrene) through a simple nucleophilic reaction to synthesize poly(styrene‐co‐styryl Meldrum's acid). Then, the pendant Meldrum's acid under thermal treatment converted to ketene intermediate resulting in highly reactive polystyrenes derivatives, which rapidly reacted by nucleophilic reagents to afford ultimate organic building blocks. The polystyrene derivatives were characterized using elemental analysis, FT‐IR, high‐resolution solid‐state NMR, thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTG). To clarify the evolutionary mechanisms of polystyrene products, density functional theory (DFT) method B3LYP with the 6–311++G(2d,p) basis set was used. We studied the preparation of polystyrene model compounds through Meldrum's acid thermolysis and nucleophilic substitution. The kinetic and thermodynamic parameters in all reactions and the structural and electronic properties of all molecules were calculated. These data exhibited that based on Gibbs Free energy values, the structure of syndiotactic polystyrene is more stable than that of isotactic polystyrene. Furthermore, it was found that the presence of an electron donor or acceptor substituent on the polystyrene structure affects the electronic bandgap.

Polystyrene Bioremediation: A Perspective on Microbial and Environmental Constrained Interventions

The polystyrene is the specific kind of plastics based upon petroleum which is composed of monomers of vinyl benzene (styrene). Regardless of the attraction of polystyrene, multiple organizations and municipalities are enduring an emerging challenge during disposal of polystyrene products and packaging. It is appraised that the products of polystyrene accounts for not more than 1% of the overall burden of landfill resources. It could be a greater health threat for humans also who are on the topmost level of food chain and farsighted styrene monomers of the plastics used in engineering polystyrene has been categorized as a potential humanoid carcinogen by the International Agency for Research on Cancer (IARC) and the US National Institutes of Health (NIH). As a few researchers have been published on the degradation of polystyrene plastic but the key point addressed in this review is the recognition of microbial and fungal enzymes which are known at present to be involved in polystyrene monomer plastic degradation. The major bacterial and fungal enzymes involved within the degradation reaction of vinyl side chain include styrene monooxygenase, styrene oxide isomerase, styrene monooxygenase, flavin adenine dinucleotide (FAD) reductase, styrene isomerase and phenyl acetaldehyde dehydrogenase. Omics”-based approaches revitalized the study of PAH catabolism by permitting for an integrative assessment of the biochemical mechanism in charge to degrade PAH including polystyrene on the polluted locations. The applications of such enzymes in procedures that would permit the degradation of polystyrene plastics contaminating niches is a dare for future cohorts of microbiology experts

Development of solid waste utilization technology in coke furnaces

In industrial centers with coke oven and by-product production, it is advisable to use existing coke ovens for the processing of the organic part of waste. At the same time, sanitary and environmental problems are solved, and the load of production capacities of the coke oven and by-chemical industry is ensured in a crisis. The target of the work is to develop the basics of technology for the use of plastic waste and coke dust in the coke oven process. In laboratory conditions, two variants of the technology of briquetting coke dust with plastic from household waste were developed. In the first version, briquettes were produced by singling a mixture of coke dust with crushed PET bottles, polystyrene and PCB products and polyethylene films at a temperature of about 220 °C. But the briquettes obtained by this method were mechanically not durable, which did not provide requirements for transportation on the conveyor. In the second version, briquettes were produced by cold pressing a mixture of coke dust with withering plastic solution in coke solvent. Such briquettes turned out to be mechanically durable, they were made about 5 kg, and industrial coking was carried out by the use of the be agree method by loading into the third hatch of the battery No. 2 of the Makeevka Coke and Chemical Plant. Coke obtained as a result of an industrial experiment of coke from the charge with the addition of briquettes was investigated according to standard methods. It was established that prior to giving 3–5% of briquettes in the coke hate, coke is possible to obtain an economical effect due to coal savings.

Debromination process of Br-containing PS of E-wastes and reuse with virgin PS

High Br-containing polystyrene (PS) plastics are generated in large quantities during the dismantling of waste CRT TVs. Debromination and reuse of Br-containing PS plastics is a critical technical challenge. Here, we demonstrate a method for combining alkaline hydrothermal debromination and co-blending granulation to achieve the regeneration of high Br-containing PS plastics. The results show the bromine concentration in PS was reduced from 49,300 mg/kg to 7420 mg/kg and from 169,000 mg/kg to 9340 mg/kg, with a removal efficiency of 84.95% at least. Then, we co-blended the debromination PS products (1 part) with qualified normal PS plastics (9 parts) for granulation. Compared to the qualified normal PS, the physical properties of the co-blended plastics remained stable in terms of the melt index, tensile strength, flexural strength andflexural modulus, which made it have good application prospects. Meanwhile, the Br concentration of co-blended PS plastics were further reduced to less than 1000 mg/kg. In summary, we provide a promising outlook of alkaline hydrothermal and co-blending (1 +9) granulation as an efficient approach for Br-containing PS plastics upgrading recycling. Novelty statementThis study provides a novel method for combining alkaline hydrothermal treatment and co-blending modification granulation process to achieve the upgrading recycling of Br-containing waste plastics. The results show the Br concentration in PS was reduced from 169,013 ppm to 9344 ppm, with a removal efficiency of 94.47%. The debromination PS products (1 part) were blended with qualified normal PS plastics (9 parts) for granulation. Compared to the qualified normal PS, the physical properties of the co-blended plastics remained basically stable, which made it have good application prospects. Also, the reuse of waste plastic can make contribution for the carbon reduction.

Is It All About the Data? How Extruded Polystyrene Escaped Single-Use Plastic Directive Market Restrictions

The Single-Use Plastics Directive (EU) 72/2019/904 is the main legislation governing plastic pollution, inclusive of marine plastic pollution in the European Union (EU). The Directive has issued market restrictions on several single-use plastic products which contribute to marine plastic pollution, including foamed polystyrene products made of expanded polystyrene (EPS). However, extruded polystyrene (XPS) which is commonly used in the same single-use plastics products as EPS has been omitted from the market placement restrictions within the scope of the Directive. This has subsequently compromised the Single-Use Plastics Directive’s effectiveness for reducing marine plastic pollution and hinders the efforts of related EU instruments such as the Marine Strategy Framework Directive, Descriptor 10 toward achieving Good Environmental Status across the marine environment in the EU. This paper provides some background on EPS and XPS, and discusses plastic pollution policy making in the EU, while further addressing the role of quantitative data in the European Joint Research Centre’s Technical Report on Top Marine Beach Litter Items in the EU for the formulation of policy regulating foamed polystyrene derived marine plastic pollution. We also provide an overview of how the communication gaps in the polymer science nomenclature for polystyrene may have contributed to the development of misnomers for extruded and EPS, consequently compromising necessary data gathering efforts. Our perspective hopes to incite conversations on communication gaps between scientists and policy makers and emphasise the need for gathering quantitative disaggregated data on the foamed polystyrene market to inform European plastic pollution legislation adequately.

Innovative fire and water insulation foam using recycled plastic bags and expanded polystyrene (EPS)

In recent decades, there has been a significant rise in the production and consumption of plastics and polystyrene products (notably Expanded Polystyrene or EPS), and the reuse of their waste nowadays, due to their pollution potentials, has come to the forefront of attention. In this paper, new green building insulation is offered and examined, combining recycled plastic layers and EPS boards. The waste plastic bags turned into plastic sheets during the simple recycling process, and a monolithic EPS was divided into several boards with different thicknesses. Then, the recycled plastic bags were placed between EPS boards. Two composites of plastic sheets and EPS boards were prepared. The first composite consists of three layers (two layers of EPS with a thickness of 20 mm each, and a 10-millimeter plastic layer consisting of 36 recycled plastic bags). The second composite includes five layers (three layers of foam with a thickness of 10 mm each, and two layers of plastic paper, each consisting of 24 recycled plastic bags). All samples were similar in dimension, thickness, foam density, and type. The two new composites were then compared with the control sample in compressive strength, water absorption, and flame spread test. Even though a dramatic reduction of compressive strength has been observed, the results reveal the suitability of both three- and five-layer composites, which considerably improves fire and water resistance compared to the control sample.

A Study of The Properties of Forming Mixtures Containing Polystyrene Wastes

Expanded polystyrene is widely used as a material for packaging, in modern construction as a heat and sound insulation layer, in thermal insulation systems for buildings, as well as tanks and pipelines. It is additionally used in foundry engineering for the production of models which are gasified during the production of castings from ferrous and non-ferrous alloys under the contact with liquid metal. The use of expanded polystyrene products is associated with waste generation, both in production and in consumption. About 40–50 kg/person of polystyrene waste is generated per year. The peculiarity of polymeric wastes is their resistance to aggressive environments. They do not rot and the destruction processes in natural conditions proceed rather slowly, with the formation of harmful substances that poison the environment. Therefore, the problem of the processing of waste from polymeric materials is of great importance, not only from the standpoint of environmental protection, but also due to the fact that in conditions of a shortage of polymer raw materials, this waste becomes a powerful raw material resource. This article describes the prospects for recycling expanded polystyrene wastes in foundry engineering. In this work, the properties of molding and core sands containing a combined binder, consisting of a solution of expanded polystyrene wastes in turpentine and clay were investigated, and their main characteristics (weight during stretching and crumbling) were determined. Molding and core mixtures, which contain only a binder in the form of a solution of expanded polystyrene in turpentine, have a crude strength of not more than 0.01 MPa. The introduction of a mixture of clay in the amount of 2–3% allows a crude strength of the mixture of up to 0.05 MPa to be obtained. After drying, the investigated mixtures containing a solution of expanded polystyrene wastes and clay have a tensile strength of up to 2.1 MPa. Mixtures into which a solution of polystyrene wastes and clay was introduced have an insignificant gas capacity and satisfactory gas permeability.

Photochemical transformation of decachlorobiphenyl (PCB-209) on the surface of microplastics in aqueous solution

• Photochemical transformation of PCB-209 on PS microplastics in water was studied. • ROS attacked PCB-209 and PS to form chlorine-related radicals and polymer radicals. • Direct photolysis, photooxidation and radical reactions were main reactions. • Products from interactions of PS with PCB-209 were also detected. • DFT calculations were used to interpret reactions of PS with OH. The accumulation of persistent organic pollutants (POPs) and microplastics in the water environment has attracted widespread attention. Given the easy adsorption of PCB-209 by microplastics, this work aimed at examining the photochemical transformation behaviors of PCB-209 on the surface of polystyrene (PS) under simulated solar irradiation. The slowest degradation was observed at pH 7.0, with a rate constant of 0.0158(±0.0004) h −1 . The presence of NO 3 − , NH 4 + and high concentrations of humic acid would inhibit the removal of PCB-209, due to the decreased amount of available free radicals. The direct photolysis of PCB-209 resulted in the formation of lower chlorinated PCBs, while the irradiation of PS could produce reactive oxygen species (ROS) and various polymer radicals. Hydroxyl radicals, as the major ROS, would attack PCB-209 to form hydroxyl substitution products, with the release of chlorine and pentachlorobenzene radicals. Polymer radicals would undergo oxidation or scission to generate olefin type products and styrene/benzene-containing products, or react with chlorine/pentachlorobenzene radicals to form (poly)chlorinated PS products. Thus, the respective transformation products of PCB-209 and PS, as well as products resulting from the interactions of the polymer with the compound were detected. Toxicity predictions by ECOSAR revealed that some intermediate products are toxic to aquatic organisms. This study provides some new insights on the environmental fate of PCBs and the photochemical roles of microplastics in sunlit surface waters.

Nationwide monitoring of microplastics in bivalves from the coastal environment of Korea.

Bivalves are useful bioindicators of microplastic contamination in the marine environment for several reasons, such as extensive filter feeding activity, broad geographical distribution, and limited movement capability. This study conducted a nationwide monitoring of microplastic pollution along the Korean coasts using filter-feeding bivalves (including oyster, mussel, and Manila clam) as bioindicators to identify the national contamination level and characteristics of microplastics. Seawater sample was collected from the same sampling stations of oyster and mussel for comparison. Microplastics were widely distributed in both coastal bivalves and waters with mean concentrations of 0.33±0.23 n/g (1.21±0.68 n/individual) in oyster/mussel, 0.43±0.32 n/g (2.19±1.20 n/individual) in Manila clam, and 1400±560 n/m3 in seawater. Despite the lack of significant relationship in the abundance of microplastics, their dominant features such as size, shape, color and polymer type were similar between bivalves and seawater. Fragments (69% for oyster/mussel, 72% for Manila clam, and 77% for seawater), particles smaller than 300μm (96% for oyster/mussel, 83% for Manila clam, and 84% for seawater) and colorless (79% for oyster/mussel, 85% for Manila clam, 75% for seawater) were the dominant shape, size and color, respectively. The major polymer types were polypropylene, polyethylene, and polyester. The microplastic level in bivalves was relatively high in urbanized areas with a wide diversity of polymer types compared with those in non-urbanized areas, and the proportion of polystyrene in the Korean samples was abundant compared with other regions due to wide use of polystyrene products in Korea. Our result suggests that microplastic contamination is widespread in the Korean coastal environment, and bivalves can reflect the microplastic pollution characteristics of the surrounding waters where they live.

Application of parabolic blending for the estimation of thickness distribution in thermoformed products

The Parabolic Blending (PB) technique has been widely used in various research fields, such as rotor noise prediction, over the last few decades. However, in the literature, PB is not utilised for the thickness prediction of thermoformed products. In this study, Polystyrene (PS) sheets of various thicknesses were thermoformed using a lab-scale thermoforming machine. Firstly, thickness distributions in thermoformed PS products were obtained by the experimental method. Then, PB was used to estimate the thickness distribution of conical semi-finished thermoformed parts. The obtained results were then compared with the ones obtained experimentally. A comparison reveals that the use of PB provides more accurate thickness values than the experimental results. As a result, PB can be utilised for the prediction of thickness distribution in thermoformed products which have been formed by the same mould.

Study on the influence of post-treatment conditions on the internal stress of polystyrene products

The polymer products in daily use generally have internal stress, and the uneven or excessive distribution of internal stress will cause warpage or stress cracking, which will affect the normal use of products. Using the heat treatment method of metal annealing to reduce its internal stress for reference, the polymer products were placed in the drying oven and water bath pot for post-treatment, and the influence of different post-treatment process parameters on the internal stress of polystyrene products represented by the mobile phone lens products was studied by using the self-developed molecular material transparent products internal stress detection device. The results showed that increasing the post-treatment temperature below the hot deformation temperature can effectively reduce the internal stress and improve the internal stress distribution of polystyrene products at the same post-treatment time under different post-treatment temperatures and slow cooling conditions, and there was an optimal post-treatment temperature of 60 Centigrade;the polystyrene products after post-treatment had the secondary internal stress under the rapid cooling conditions, so that the internal stress distribution of products was worse than that of polystyrene products without post-treatment. The experimental results can lay a theoretical and practical foundation for seeking effective measures to reduce the internal stress of polymer products in the future.

Study of properties of adhesive formed by waste polystyrene

The polystyrene products involved in day to day life serve to its best as per its utility. I t possesses the several properties like Insulation, Light in weight, Cushioning, Non-Reactive Material and Non- Biodegradable. Serving multipurpose it finds wide application in food industry for food packaging, material packaging in the electrical device sector, construction sector etc. There are demerits associated with the product after use i.e. waste product disposal is the major problem incurred curre ntly. It is becoming a part of landfill and increasing the amount of solid waste. It can even harm animals that scavenge food from the landfills. Our project aims to reduce and develop methodologies to treat the polystyrene waste.

Exposure route affects the distribution and toxicity of polystyrene nanoplastics in zebrafish

The widespread use of polystyrene (PS) products in a myriad of consumer products has resulted in widespread contamination of PS nanoplastics (PSNPs) in aquatic ecosystems. Fish early life stages are exposed to nanoplastics dermally and via gills. Additional routes of exposure include oral via the ingestion of contaminated prey and maternal transfer. However, there is limited amount of work studying the impact of exposure route in the toxicokinetics and toxicodynamics of PSNPs. The objective of this study was to compare the effects of exposure routes (aqueous and microinjection) on the organ distribution and toxicity of PSNPs. We “mimicked” the maternal exposure of PSNPs to zebrafish by injecting a known concentration of fluorescent particles directly into 2-cell stage embryos. Endpoints were collected starting at 96 h post-fertilization until several weeks post-hatch to evaluate depuration. Although both exposure routes led to the accumulation of PSNPs in the yolk sac followed by brain, eyes, gut and swim bladder, the aqueous exposure caused higher PSNP concentrations in the brain and eyes and the injection exposure caused PSNP accumulation mainly in the trunk area. A waterborne exposure also reduced antioxidant gene expression; increased frequency of developmental abnormalities such as bent tails, jaw deformities and pericardial edema; and resulted in lower growth rates and hypoactivity. Overall, a waterborne exposure to PSNPs resulted in higher transfer to the brain and caused greater toxic effects to zebrafish compared to an injection exposure and highlights the key role of exposure routes in the uptake, localization and subsequent distribution of nanoparticles.