Introduction Of Plastics Research Articles

Photochemical Aerobic Upcycling of Polystyrene Plastics.

Although the introduction of plastics has improved humanity's everyday life, the fast accumulation of plastic waste, including microplastics and nanoplastics, have created numerous problems with recent studies highlighting their involvement in various aspects of our lives. Upcycling of plastics, the conversion of plastic waste to high-added value chemicals, is a way to combat plastic waste that is receiving increased attention. Herein, we describe a novel aerobic photochemical process for the upcycling of real-life polystyrene-based plastics into benzoic acid. A new process employing a thioxanthone-derivative, in combination with N-bromosuccinimide, under ambient air and 390 nm irradiation is capable of upcycling real-life polystyrene-derived products in benzoic acid in yields varying from 24-54%.

Thermal-oxidative stability of PVC compositions modified with a bromine-containing plasticizer-flame retardant

The possibility of creating polymer compositions based on polyvinyl chloride plasticized with a bromine-containing flameretarding plasticizer has been investigated. Their thermostability at introduction of plasticizer with different bromine content was evaluated. The optimal concentrations of bromine in the flame-retarding plasticizer to increase the thermal stability of the polymer composition have been established. It is noted that increasing the concentration of bromine in the flame-retarding plasticizer increases the rate of elimination of hydrogen bromide and slows down the thermal destruction of the polymer matrix. It is shown that during thermo-oxidative degradation of plasticized PVC composite, hydrogen bromide is first eliminated from flame-retarding plasticizer, which accelerates the process of polyene formation and additional cross-linking of polymer macromolecules. An increase in the tensile strength of plasticized compositions at the introduction of optimal dosages of flame-retarding plasticizer was observed.

STUDY OF LITERATURE REVIEW ON THE USE OF PLASTIC IN CONCRETE MIXES

Plastic waste poses significant environmental challenges due to its widespread use and long-lasting nature. In the search for sustainable construction solutions, this study presents a systematic review of international research spanning two decades on the integration of recycled plastics into concrete mixtures, either as aggregates or fibers. Applying strict inclusion and exclusion criteria, 97 of the 187 articles initially identified were analyzed in depth. Key findings indicate that the introduction of plastics can influence essential concrete properties such as density, compressive strength and thermal conductivity. The effectiveness of plastic integration largely depends on factors such as the type, size and shape of the plastic used. In particular, the research reveals that the use of plastic fibers can improve crack resistance, influenced by the size and type of fiber. Depending on the application, an optimal plastic replacement percentage is usually between 10% and 20%. This review highlights the potential of recycled plastics to increase the properties of concrete, offering an environmentally friendly route to reduce plastic waste and promote sustainable construction.

Anionic Anchoring Enhanced Quasi Solid Composite Polymer Electrolytes for High Performance Lithium Metal Battery.

Herein, ZIF-8 inorganic particles with different sized reinforced poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) solid composite polymer electrolytes (PVDF-HFP/10%ZIF-8) were prepared via a facile blade-coating approach, and free-standing quasi solid-state composite electrolytes (PVDF-HFP/10%ZIF-8(0.6)/Plasticizer, abbreviated as PH/10%ZIF-8(0.6)/P), were further obtained through the introduction of plasticizer. Optimized PH/10%ZIF-8(0.6)/P exhibited a high ionic conductivity of 2.8 × 10-4 S cm-1 at 30 °C, and superior Li+ transfer number of 0.89 with an ultrathin thickness (26 µm). Therefore, PH/10%ZIF-8(0.6)/P could effectively inhibit the growth of lithium dendrites, and the assembled Li/LiFePO4 cell delivered good cycling stability with a capacity retention rate of 89.1% after 100 cycles at 0.5 C.

Increase in physical and mechanical properties of decorative concretes for the post‐war restoration of residential and public buildings in the Kharkiv region with the addition of highly dispersed calcite (chalk)

AbstractDuring the war active, a huge number of residential and public buildings were destroyed not only in Kharkiv and the region, but throughout Ukraine. For the restoration of destroyed buildings, new types of cement will be needed to look for and will be created decorated concretes based on them that would provide high operational and technological properties of constrictions and will be focused on local materials. Carbonate additive such as highly dispersed calcite (chalk) can be used for as local additive for concrete due to significant reserves are located in Kharkiv region. In the article research on the impact of joint action additive of highly dispersed calcite (chalk) and natural pigment (ocher) is presented by physical and mechanical properties such as density, strength, water resistance, and frost resistance. It has been established that, depending on the percentage of highly dispersed calcite (chalk), the physical and mechanical properties are changed irregularly. On the basis of the conducted researches it was established that the optimal amount of the addition of high‐fossil chalk, which provides increased frost resistance and corrosion resistance of concrete in an aggressive environment, containing chlorides, sulfates and magnesium ions, is from 10 % to 30 %. In addition, it increases density, compressive strength, stretching strength at bending. At the same time, it should be noted at an increased amount of fine chalk to 40% leads to a decrease in physical and mechanical characteristics. But the introduction of plasticizer in the amount of 0.5% leads to increased compressive strength and, accordingly, increases the positive qualities of chalk. The concrete compositions that getting with high decorative and operational properties are allowed to use them for the restoration of the city and increase in urban space.

Manufacturing and testing of waste PET reinforced with sand bricks

The high and increasing demand for plastic materials has led to a global challenge in the form of plastic pollution, because of the different types of discarded plastic, such as polyethylene terephthalate (PET), polypropylene (PP), and high-density polyethylene (HDPE), etc.; it has become difficult to recycle it. Thus, only a limited percentage of plastic is recycled. Many studies in this field are trying to find alternative solutions such as the introduction of plastic in building materials. This study examines brick particles as reinforcement in polyethylene as a matrix. 30%, 35%, 40%, and 45% of weighted brick sand were combined with PET and prepared by melt compounding and processed through a single-screw extruder at 260°C. Thermal properties were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results show that in the presence of brick particles, the thermal degradation temperature of the composites increased. The composite that contains 45% of brick sand weight attempted 314.323°C as the highest degradation temperature, as well as the glass transition temperature. Mechanical tests show that the addition of brick in the matrix leads to a significant reduction in impact resistance. Static failure stress reaches 26.26 (MPa) in a composition of 30% of the brick sand weight. Young’s modulus shows better results in 30% of weighted brick sand equal to 2,771 (MPa). The scanning electron microscope (SEM) reveals a uniform distribution of the reinforcing charge.

Development of a yeast whole-cell biocatalyst for MHET conversion into terephthalic acid and ethylene glycol

BackgroundOver the 70 years since the introduction of plastic into everyday items, plastic waste has become an increasing problem. With over 360 million tonnes of plastics produced every year, solutions for plastic recycling and plastic waste reduction are sorely needed. Recently, multiple enzymes capable of degrading PET (polyethylene terephthalate) plastic have been identified and engineered. In particular, the enzymes PETase and MHETase from Ideonella sakaiensis depolymerize PET into the two building blocks used for its synthesis, ethylene glycol (EG) and terephthalic acid (TPA). Importantly, EG and TPA can be re-used for PET synthesis allowing complete and sustainable PET recycling.ResultsIn this study we used Saccharomyces cerevisiae, a species utilized widely in bioindustrial fermentation processes, as a platform to develop a whole-cell catalyst expressing the MHETase enzyme, which converts monohydroxyethyl terephthalate (MHET) into TPA and EG. We assessed six expression architectures and identified those resulting in efficient MHETase expression on the yeast cell surface. We show that the MHETase whole-cell catalyst has activity comparable to recombinant MHETase purified from Escherichia coli. Finally, we demonstrate that surface displayed MHETase is active across a range of pHs, temperatures, and for at least 12 days at room temperature.ConclusionsWe demonstrate the feasibility of using S. cerevisiae as a platform for the expression and surface display of PET degrading enzymes and predict that the whole-cell catalyst will be a viable alternative to protein purification-based approaches for plastic degradation.

Application of Recycled Plastics in Automotive Industry: a short review

The paper describes application of recycled plastic materials in the automotive industry. It deals with various types of recycled plastics used in vehicle interiors / exteriors. Introduction of plastics into cars brings about reduction in weight of the vehicle, resulting in reduced fuel consumption and increased performance. Since the quantity of generated plastic waste is extreme, the issue of recycling is highly topical.

Bacterial dynamics during the burial of starch-based bioplastic and oxo-low-density-polyethylene in compost soil

BackgroundPlastic waste accumulation is one of the main ecological concerns in the past decades. A new generation of plastics that are easier to degrade in the environment compared to conventional plastics, such as starch-based bioplastics and oxo-biodegradable plastics, is perceived as a solution to this issue. However, the fate of these materials in the environment are unclear, and less is known about how their presence affect the microorganisms that may play a role in their biodegradation. In this study, we monitored the dynamics of bacterial community in soil upon introduction of commercial carrier bags claimed as biodegradable: cassava starch-based bioplastic and oxo-low-density polyethylene (oxo-LDPE). Each type of plastic bag was buried separately in compost soil and incubated for 30, 60, 90, and 120 days. Following incubation, soil pH and temperature as well as the weight of remaining plastics were measured. Bacterial diversity in soil attached to the surface of remaining plastics was analyzed using Illumina high-throughput sequencing of the V3-V4 region of 16SrRNA gene.ResultsAfter 120 days, the starch-based bioplastic weight has decreased by 74%, while the oxo-LDPE remained intact with only 3% weight reduction. The bacterial composition in soil fluctuated over time with or without the introduction of either type of plastic. While major bacterial phyla remained similar for all treatment in this study, different types of plastics led to different soil bacterial community structure. None of these bacteria were abundant continuously, but rather they emerged at specific time points. The introduction of plastics into soil increased not only the population of bacteria known for their ability to directly utilize plastic component for their growth, but also the abundance of those that may interact with direct degraders. Bacterial groups that are involved in nitrogen cycling also arose throughout burial.ConclusionsThe introduction of starch-based bioplastic and oxo-LDPE led to contrasting shift in soil bacterial population overtime, which may determine their fate in the environment.

Nanomodification of the system СаО−SO3−H2O

Problem statement. The process of structure formation generally depends on the initial composition of binders and additives affecting the hydration process. Analysis of the technical literature shows that in the manufacture of mineral binders, preference is given to the creation of composite binders and the use of various additives and factors influencing the hydration process. Particular interest are nanoadditives. Purpose of research. Determination of surfactants and nanoadditives influence on the process of hydration and structure formation for gypsum binders. Conclusions. Investigations on the directional regulation of the gypsum binders’ properties have shown that the specific surface area of various anisotropic surfaces regulates the shape of the crystals as well as their formation and growth kinetics. It was found that the process of gypsum binders hydration and formation can be regulated using the specific surface dimensions, the nanoadditives parameters, as well as by changing the concentration in the solution. The influence of micro- and nanoadditives on the change of the system surface energy, as well as on introduction of plasticizer and change of time solution is in the supersaturated state (which increases the number of nuclear centers of crystallization) was experimentally and theoretically determined and proved.

Recycling of Waste Plastic into Fine-Grained Concrete Without Strength Reduction

The problem of recycling plastic waste is quite acute both in Ukraine and for most countries of the world. The use of plastic processing products can be considered an urgent problem of society from the point of view of environmental protection and environmental safety. Today, developments are underway in the field of using polymers in one of the largest sectors of production – the construction industry. In recent years, the scientific community has been actively studying the issue of using plastic waste in the manufacture of reinforced concrete structures, that is, partial replacement of the filler with plastic particles. At the same time, in the short term, sufficient resources of plastic waste will be provided, which will come in value for collection and recycling. The use of plastic in concrete production technology will not only reduce the negative impact of waste on the environment, but also develop concrete of more sustainable quality and lower cost. The aim of the study is determining the amount of plastic waste that can be utilized through introducing it into concrete mix without reducing the strength of the concrete. Here we have considered the issue of the impact of the degree of plastic grinding on concrete strength. The research findings show that the introduction of plastic in an amount up to 3.5% of the volume of concrete as a substitute for the aggregate does not reduce its compressive or flexural strength.

РЕЗУЛЬТАТЫ ЭКСПЕРИМЕНТАЛЬНЫХ ИССЛЕДОВАНИЙ ПРОЦЕССА ШТАМПОВАНИЯ ДРЕВЕСИНЫ МЯГКИХ ПОРОД

Stamping of softwood is still a poorly researched process of chipless division. The research on commercially available equipment was carried out. Multivariate experiments were held according to standard methods with the number of measurements from 20 to 150 using softwood including conifers. A computer was used to substantiate the obtained coefficients of the regression equations. The magnitude of external factors such as loading mode, duration and the introduction of plasticizers were studied. Exploratory experiments made it possible to accurately establish the magnitude of the external load during direct and oblique collapse, as well as the optimal deformation temperature. Moreover, the studies were carried out taking into account the different moisture content of the wood. Regression models for four factors with two outputs were obtained. Insignificant coefficients were excluded and further research of the influence of humidity, temperature, section size and shape of the work piece on the surface quality of stamped parts were carried out. As a result, the dependence of the magnitude of deformations in wood on load and temperature was built. Solving the optimization problem made it possible to identify the following parameters of the processes of stamping softwood: density within 400 kg/m3 and temperature 156 degrees Celsius

Reclamation of Potholes by Utilisation of Plastic

The rate of accidents caused by potholes is increasing day by day. So, potholes must be repaired as soon as possible. This paper aims to repair potholes by using plastic. The introduction of plastic in bitumen modifies the characteristic of bitumen. Tests were done on aggregate and bitumen to check their quality. Marshall Test on bitumen were done on different percentage of bitumen and plastic. From the result it was observed that as the percentage of plastic is increased the stability value of Marshall test is also increased.

A Comparative Study on Plastic Concrete and Partially Replaced Plastic Concrete using Plastic Aggregate with Conventional Concrete

Solid waste management is one of the major environmental concerns in our country now a day. The present study covers the use or recycled plastics as replacement of coarse aggregates in concrete. The main aim of the study is to investigate the change in mechanical properties of concrete with the addition of plastics in concrete. Along with the mechanical properties, thermal characteristics of the resultant concrete are also studied. It is found that the use of plastic aggregates results in the formation of lightweight concrete. The compressive, as well as tensile strength of concrete reduces with the introduction of plastics. The most important change brought about by the use of plastics is that the thermal conductivity of concrete is reduced by using plastics in concrete. Therefore, it can be said that recycled plastics can be used for thermal insulation of buildings.

Nanomodification of mineral binders

In the result of researches performed on the directed regulation of properties of gypsum binders, it was determined that the specific surface of various anisotropic surfaces regulates the shape of crystals as well as kinetics of their formation and growth. It has been established that the process of hydration and formation of gypsum binders can be regulated through the size of the specific surface, parameters of nanoadditives as well as through the change of concentration in solution. The influence of micro - and nanoadditives on the change of the system surface energy, as well as on introduction of plasticizer and change of time solution is in the supersaturated state (which increases the number of nuclear centers of crystallization) has been established experimentally and theoretically proved.

Fuel Oil from Plastic Waste

In Earlier days PLASTIC was a revolutionary invention which brought many changes in industrial & daily activities. But now a days, it has become a major problem as it is increasing the landfills which is leading to more pollution because of its high degradation time and no proper disposable way which is affecting the environment. The global production of plastic has shown an increase from around 1.3 MT in 1950 to 300 MT in 2010 due to the introduction of plastic in various fields. Out of the total consumption of plastic,53 % constitute polyolefins which is a large hydrocarbon. Polyethene is most consumed one i.e. 33% of total due to this it is taken into consideration. To overcome this problem, we used Thermal Cracking i.e. Pyrolysis, it is a process which converts the large hydrocarbon chains in to small hydrocarbon chains by heating the plastic at high temperature (350 – 400℃) & the products obtained are fuel oil and non- condensable fractions. The fuel oil can be used for heating purposes and non-condensable fractions to reduce air pollution. Polythene, Polypropylene are used as they are pure hydro-carbons and burnt completely.

The introduction of plastic and reconstructive surgery to the University of Glasgow undergraduate medical core curriculum.

Misperceptions of plastic surgery remain common among medical students and the medical community. This creates barriers in recruitment to specialty and patient referral. Before this study, there was no formal...

Modification of epoxy matrix by whiskers of potassium polytitanate

Studies show the possibility to directionally control the performance properties of epoxy composites by the use of small additions of whiskers of potassium polytitanate, the introduction of plasticizers of multifunctional action, and the methods of chemical and mechanical activation of composition components and the composition as a whole. This provides the creation of the next-generation epoxy composites with high performance (the breaking stress and the flexural modulus of 96 and 3150 MPa, the compressive breaking stress of 95 MPa, and the toughness of 18 kJ/m2), which meets the usual industrial requirements. In addition, the influence of potassium polytitanate whiskers on the structure formation processes of epoxy resin is established, which is shown by the increase in the gel time from 45 to 64 min and the curing time from 53 to 104 min.

Mechanically Robust and Highly Conductive Polybenzimidazole(PBI)-Based Reinforced Membrane for High Temperature Polymer Electrolyte Membrane Fuel Cell

Operating polymer electrolyte membrane fuel cell(PEMFC) at high temperatures (HT, 100oC~200oC) is beneficial owing to fast kinetics for electrochemical reactions and high tolerance to carbon monoxide(CO) poisoning. Also, the HT operation allows a simpler system design by eliminating water management and PROX. However, current HT-PEMFCs still suffer from insufficient power performance partly originating from large membrane resistance. Typically, HT-PEMFC employs the phosphoric acid-doped PBI membrane and its proton conductivity depends on the acid doping level. Therefore, increasing the doping level is prerequisite for high power performance of HT-PEMFC. However, phosphoric acid doping level is practically limited by a decreased mechanical stability of the membrane with acid doping. To mitigate the problems caused by the loss of low mechanical strength with the acid doping, a thick PBI membrane (>100um) is conventionally employed although its large membrane resistance and consequent negative influence on power performance. Against this backdrop, in this study, we present a novel approach for addressing the trade-off between proton conduction and mechanical robustness of PBI based HT membrane. For fabricating an reinforced PBI membrane coupled with a porous PTFE membrane, PBI filling in a porous PTFE membrane is highly challenging due to low compatibility between hydrophobic PTFE and hydrophilic PBI. In this work, to make the PTFE surface hydrophilic, a porous PTFE membrane is treated with dopamine which is as known nature-inspired adhesive and self-polymerized into polydopamine via a pH-induced oxidation. A polydopamine layer can be formed on the PTFE surface by simply immersing the porous PTFE membrane in the aqueous buffered dopamine solution at room temperature. Compared to the pristine PTFE membrane, the polydopamine-treated PTFE membrane is more densely filled with PBI after the impregnation of PBI solution, indicating an effective intrusion of the PBI solution into the modified hydrophilic pores. The reinforced membrane shows a higher mechanical strength after phosphoric acid doping process even at a thin membrane thickness(~50um) in comparison with a 100 micron thick un-reinforced PBI membrane. The second feature of this approach is the introduction of plasticizer in the PBI matrix for increasing the acid doping level for the reinforced PBI/PTFE membrane. In general, mechanical supports suppress swelling of the PBI matrix with phosphoric acid solution, resulting in a lower acid doping level compared to that of pristine PBI membrane. However, poly(ethylene glycol) (PEG), which can be exchanged with phosphoric acid, provides an additional space for accommodating phosphoric acid in the PBI matrix when incorporated in the PBI matrix. PEG and PBI forms a miscible blend and PEG can be extracted out during the acid doping process, being exchanged with phosphoric acid as confirmed by DSC and FT-IR analysis. The PEG/PBI blend exhibits a higher mechanical stability owing to its lower expansion but a higher proton conductivity owing to its high acid doping level after the acid doping, clearly demonstrating the benefit of the approach. When the PEG-plasticized PBI matrix and polydopamine-treated PTFE support are combined, the mechanical stability can be significantly improved compared with the PEG-plasticized PBI membrane and the proton conductivity be enhanced compared with the PTFE-reinforced PBI membrane. The power performance of an in-house membrane electrode assembly (MEA) employing the novel reinforced membrane is comparable to that of a commercial HT-MEA. Therefore, the combined strategy can overcome the trade-off between mechanical stability and proton conductivity in the design of HT-PBI membranes.

Using polymer waste in coke production

The utilization of solid domestic waste—plastic, rubber, leather, textiles, wood, and paper—in coking batch after mixing with residues from coal-tar stores at coke plants is investigated. All the solid domestic waste considered—especially plastic waste—increase the yield of coke in the >80 and >60 mm class and the yield of tar and benzene. The introduction of plastics and a mixture of solid domestic waste with up to 1% of tar-storage residues does not impair the quality of the coke produced.