Plastic Polymers Research Articles

Indigenous Development of Epoxy Resin System for Cryogenic Services and Fusion Application

An epoxy resin system is used in a superconducting tokamak to insulate the conducting components, such as superconducting windings, cooling pipes, metal electrodes, and bonding and sealing of dissimilar material joints at cryogenic temperature. The main aim is to develop and fabricate the dissimilar material joints of metal and glass fiber reinforced plastic (GFRP) polymer in the form of cryogenic components for the superconducting fusion magnet. To bond and fabricate the dissimilar joints, the epoxy resin needs to have low viscosity, good adhesion, resistance to moisture, long usable life, and high toughness at low temperatures. A two-component-modified diglycidyl ether of bisphenol-A (DGEBA) epoxy resin was formulated with a modified polyamine-based hardener. To increase the toughness and minimize the induced thermal stress at low temperatures, a silane coupling agent, gamma-aminopropyltrithoxysilane, was used for its superior bonding and fast curing process. The tensile strength examination test results were found to 85 MPa, as per the International Organization for Standardization standard ISO 527-2, and an interlaminar shear strength of 12 MPa was found, as per the American Society for Testing and Materials standard ASTM D5868 at 77 K, respectively. The mechanical performance enhancements at 77 K overcome the issue of cracks and helium leaks that develop at cryogenic temperatures, as reported. The dissimilar material joints fabricated using the epoxy resin in the form of a cryo component have been validated in machine with an acceptable helium leak tightness of 1.0E-08 mbar-l/s. In this work, we report on the development, mechanical, thermal, and electrical performance tests, the testing and failures of various epoxy resins systems used, and the cryo components at 300 and 77 K.

Quantifying microplastics pollution in the Red Sea and Gulfs of Suez and Aqaba: Insights from chemical analysis and pollution load assessment

Microplastics (MPs) constitute the majority of marine plastic litter. The pollution caused by MPs has been categorized as a gradual and persistent crisis, but little is known about its extent along the shores of the Red Sea, particularly on the Egyptian side. The Red Sea is a rapidly developing region and home to critical ecosystems with high levels of endemism. This study represents the first comprehensive survey investigating the extent of MP pollution along the Egyptian shores of the Red Sea, including the Gulf of Suez and Aqaba. Mean concentrations ranged from 23.3 ± 15.28 to 930.0 ± 181.9 MPs/kg DW. Out of 17 beaches surveyed, 12 had mean concentrations of <200 items/kg, indicating a low occurrence of MPs compared to the shores of the Mediterranean Coast of Egypt. The pollution load index varied from low to medium levels in most locations. Ras Mohamed, a marine protected area, showed high vulnerability to MP pollution. All the investigated particles were fragments of secondary MPs. The sources of pollution mainly come from maritime activities, including cargo shipping and intense recreational activities. Fourier Transform Infrared Spectroscopy identified four plastic polymers, with polyethylene and polypropylene being the most common. The surface morphology of plastic particles was examined using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. All the particles exhibited signs of degradation, which could generate countless plastic pieces with possible deleterious impacts. This work has highlighted the importance of conducting region-specific assessments of mismanaged plastic waste, focusing on the role of tourism and recreational navigation as contributors to plastic litter, to estimate plastic waste inputs into the waters of the Red Sea Coast of Egypt. Efforts are needed to develop strategic plans to reduce the disposal of plastic waste in the region.

Oral Dissolving Film of Rivastigmine: Optimization Using Factorial Design

PurposeDue to impairments in memory and judgment, it is difficult for dementia patients to understand why they need medicine. Moreover, they often have swallowing difficulties. In this investigation, an oral dissolving film of rivastigmine tartrate (RT-ODF) was developed, offering a unique and convenient formulation for dementia patients.MethodsRT-ODF was developed using a solvent-casting technique. Sodium alginate and sodium carboxymethyl cellulose were used as film-forming polymers, and glycerol was used as a plasticizer. A full factorial design (32) was employed to estimate the impact of two factors at three levels: polymer concentration (1, 1.5, and 2% w/v) and plasticizer concentration (30, 40, and 50% w/v) on the responses, i.e., the tensile strength (TS), the disintegration time (DT), and the quantity of drug released (Q10 min).ResultsThe optimized formula (A1) that had the highest desirability value (0.923) exhibited the lowest tensile strength (3.67 ± 0.72 MPa), the shortest disintegration time (20 ± 2.0 s), and the highest percentage of drug released after 10 min (97.12 ± 2.01%). It was composed of 1% w/v sodium alginate (ALG-Na) and plasticized with 30% w/v glycerol. The pharmacokinetic study revealed that the RT-ODFs enhanced the drug’s bioavailability by 1.91-fold relative to the reference product (Exelon® capsule).ConclusionOral dissolving films of rivastigmine tartrate could be a promising approach to promote drug bioavailability and convenience for geriatric patients.

Characterization of Microplastics and Mesoplastics and Presence of Biofilms, Collected in the Gualí Wetland Cundinamarca, Colombia

Wetlands are being contaminated by housing developments, effluents, industrial areas, and poor sanitation, resulting in the presence of plastic polymers and the development of biofilms on these materials, which represent an elevated risk to freshwater fauna and flora. The objective of this study was to characterize mesoplastics and microplastics, collected in the Gualí Wetland, Colombia, as well as to verify the presence of biofilms on such polymers. Nine water samples (36 L per sample) were evaluated at three points of the wetland; the size of the particles was determined by image analysis, the type of polymer through FTIR, and the presence of biofilms by microscopy. A total of 79 items/0.135 m3 were collected, 2 macroplastic items, 53 mesoplastic items, and 24 microplastic items. The presence of fragments (70%) and pellets (41%), with transparent (40%) and white (30%) being the predominant ones, was outstanding. Among the polymers, high-density polyethylene (HDPE) dominated, followed by expanded polystyrene. The results of SEM demonstrated the presence of diatoms on the surface of the plastic polymers. Furthermore, the results showed a greater amount of HDPE mesoplastics and microplastics in the shape of fragments and pellets. In addition, the presence of biofilms on these plastic particles can increase the adsorption of contaminants, negatively affecting this ecosystem. The outcome of this study can be used to identify bacteria that reside in biofilms associated with microplastics and mesoplastics.

Optical, vibrational, electrical, and electrochemical studies of new plasticized methylcellulose‐based solid polymer electrolytes for supercapacitor application

AbstractIn this work, new plasticized solid polymer electrolytes (SPEs) are developed using MC (methylcellulose) as a polymer host, and sodium iodide (NaI) as a dopant via the solution casting method. Ethyl carbonate (EC) is used as a plasticizing agent to improve the properties of the SPEs. Polarized optical microscopy analysis reveals that the surface morphology of the MC‐NaI‐EC films contained porous amorphous regions owing to the presence of EC. The complex formation between MC, NaI, and EC is confirmed by Fourier‐transform infrared spectra. The addition of EC in the MC‐NaI polymer salt matrix enhances the electrochemical properties of the prepared films. The highest ionic conductivity of 5.06×10−3 S/cm is achieved for the composition: MC+50 wt. % NaI +10 wt. % EC. The linear sweep voltammetry test reveals that the optimal plasticized‐SPE can withstand up to 2.5 V. The ionic transference number analysis reveals that 99% of ions contribute to the total conductivity. The optimized SPE film and graphene oxide‐based electrodes are used to manufacture a solid‐state electrical double‐layer capacitor. The coulomb efficiency of the supercapacitor cell is 100%, and the specific capacitance of the supercapacitor is found to be 18.56 F/g utilizing impedance data at low frequency.

Review of Bioplastics Characterisation by Terahertz Techniques in the View of Ensuring a Circular Economy

The increasing scarcity of natural resources, worsening global climate change, environmental degradation, and rising demand for food are forcing the biotechnology and plastics industries to seek and apply circular economy models that would lead to a sustainable transition in the production and use of bioplastics. Circular economy models can improve the economic productivity of bio-based plastics and have a positive impact on the environment by reducing conventional plastic waste and the consumption of petrochemical feedstocks for plastic production. In addition, some agricultural wastes that have the potential to be used as bioplastics can be reused. Terahertz (THz) systems are already used in the plastics and rubber industries for non-destructive testing, detection, imaging, and quality control. Several reports have highlighted the potential applications of THz spectroscopy and imaging in polymer analysis and plastics characterisation. This potential is even greater with chemometric methods and artificial intelligence algorithms. In this review, we focus on applications that support the transformation of the biotechnology sector to the circular economy, particularly via the transition from conventional plastics to bioplastics. In this review, we discuss the potential of THz systems for the characterisation and analysis of bioplastics and biopolymers. The results of previous studies on biopolymers in the THz frequency range are summarised. Furthermore, the potential of using artificial intelligence approaches such as machine learning as advanced analytical methods in THz spectroscopy and imaging, in addition to the conventionally used chemometric methods, is discussed. The results of this review highlight that THz technology can contribute to closed technological circles in important areas of biotechnology and the related plastics and rubber industries.

Sublethal effects of bio-plastic microparticles and their components on the behaviour of Daphnia magna.

Bioplastics arise as an alternative to plastic production delinked from fossil resources. However, as their demand is increasing, there is a need to investigate their environmental fingerprint. Here we study the toxicity of microplastics (MPLs) of two widely used materials, the polylactic acid (PLA) and the polyhydroxybutyrate (PHB) on the environmental aquatic model species Daphnia magna. The study was focused on sublethal behavioural and feeding endpoints linked to antipredator scape responses and food intake. The study aimed to test that MPLs from single-use household comercial items and among them bioplastics should be more toxic than those obtained from standard plastic polymers and fossil plastic materials due to the greater amount of plastic additives, and that MPLs should be more toxic than plastic extracts due to the contribution of both particle and plastic additive toxicity. MPLs were obtained by cryogenic grinding and sea-sand erosion to obtain irregular particles. MPL included standard polymers and nine comercial items of PLA and PHB and one fossil-based material of high-density polyethylene (HDPE). The additive content in commercial items was characterised by liquid chromatography coupled with high-resolution mass spectrometry. D. magna juveniles were exposed for 24 h to particles and their plastic extracts. Results indicated that the toxicity of bioplastic particles was five times higher than the effects produced by exposure to the content of the additives alone, that bioplastic particles were more toxic than fossil ones and that particles obtained from commercial items were more toxic than those obtained from PLA, PHB or HDPE polymer standards. Predicted toxicity from the measured plastic additives in the studied commercially available household items, however, was poorly related with the observed behavioural and feeding effects. Further research on unknown chemical components together with physical factors is need it to fully understand the mechanisms of toxicity of bioplastic materials.

A Stretchable Polymer Conductor Through the Mutual Plasticization Effect.

Intrinsically stretchable conductors play key roles in the dynamic interfacing of electronic devices with soft human tissues. However, it is difficult to simultaneously achieve high electrical conductivity and mechanical stretchability. Here, we prepared highly stretchable and conductive thin film electrodes by combining PEDOT:PSS and a mutually plasticized polymer dopant. Notably, harsh acid treatment for conductivity enhancement was avoided, and good solvent tolerance and high optical transparency were realized, all of which are essential to device fabrication. We further developed a transparent electrochromic display that can bear stretching up to 80% strain, demonstrating its promising application in next-generation optoelectronics. This article is protected by copyright. All rights reserved.

An advanced analytical approach to assess the long-term degradation of microplastics in the marine environment

Determining the hazards posed by microplastics (MPs, <5 mm) requires an understanding of plastic degradation processes when exposed to environmental weathering forces. However, despite their perceived risks, limited information exists on the natural weathering progression of microplastics in marine environments. Our findings from environmentally realistic conditions reveal that long-term marine weathering resulted in significant degradation of plastic surfaces and bulk-phases, which varied by time and plastic polymer type. Plastics displayed biofouling, and an altered surface morphology, thermal stability and chemical signature. Secondary micronanoplastics (MNPs, <1 µm) were formed from weathered plastic surfaces, supported by a significant reduction in the size of PCL and PVC pellets. Using real world data, we reveal that plastic surfaces can degrade at a rate of up to 469.73 µm per year, 12 times greater than previous estimates. Our time-series data contributes valuable information towards developing plastic specific risk assessment frameworks and future plastics policy.

Safety issues in nutraceutical exploitation of Chlorella vulgaris, Arthrospira Platensis and Scenedesmus sp. microalgae

Microalgae contain many bioactive compounds, which may be exploited in food and nutraceutical fields. Bisphenol A (BPA) is a contaminant in microalgae that may be released from polymeric plastics. Since it is responsible for toxic effects on humans, the European legislation set the legal BPA limit within foods at 50 µg kg−1 of food weight. In this work, a fast ultrasounds solid-liquid extraction of BPA from commercial microalgal powders of Chlorella vulgaris, Arthrospira Platensis and Scenedesmus sp. was optimized. To increase selectivity, BPA was derivatized by using N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (BSTFA-TMCS) and it was analysed by GC-MS in selected ion monitoring mode. A design of experiment (DOE) optimization study of the reaction conditions was performed. The analytical method was validated by determining selectivity, linearity (R2= 0.99999 ± 3.3165E-07), precision, accuracy (99.92 ± 9.83E-02 %), recovery (99.65 ± 3.61E-02 %) and sensitivity (LoD= 0.547 ± 9.94E-02 µg kg−1; LoQ= 1.823 ± 3.31E-1 µg kg−1). The overall method proved to be fast, with high recovery and suitable to selectively and sensitively determine the content of BPA, eliminating the interferences from extraction and allowing to control the safety profile of microalgae. Dried microalgae cultivated in a polycarbonate reactor, were found to contain an amount of BPA 6 times exceeding the legal limit.

Abundance, Distribution, and Characterization of Microplastics on Two Recreational Beaches in Kota Kinabalu, Sabah, Malaysia

Currently, there is a lack of assessment of the level of microplastics (MPs) pollution on recreational beaches around the world. Therefore, this study was conducted to determine the current state of MP pollution on two popular recreational beaches of Kota Kinabalu, Sabah, namely, (1) Tanjung Aru Beach and (2) UMS ODEC (Outdoor Development Center) beach. MPs from the sediments were extracted using the density separation method and analyzed through a stereoscopic microscope. The overall MPs abundance, weight, size, colors, and polymer types were recorded. Tanjung Aru beach recovered higher numbers of MPs particles for all stations, with 857 MPs/kg dry sediment with a total mass concentration of 57.72 g/kg, while UMS ODEC recorded 160 MPs/kg particles with a total mass concentration of 17.96 g/kg. The maximum MPs abundance was observed in the size of &lt;1 mm with a high proportion of white/transparent coloring. Micro Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that polypropylene (PP:60%) and polyethylene (PE:43%) were the two most common plastic polymers found on both beaches, followed by polyethylene terephthalate (PET), and the least common was polystyrene (PS). Metals (arsenic, chromium, copper, and nickel) were found within the MPs collected. The present study demonstrated an alarming quantity of MPs on two recreational beaches in Kota Kinabalu, Sabah, Malaysia. However, information concerning the primary sources, local dynamics, and repercussions of MPs in this location is still limited; thus, further research is required.

Mechanical Properties of Polyamide Fiber-Reinforced Lime–Cement Concrete

Lime–cement concrete (LCC) is a type of lime-based concrete in which lime and cement are utilized as the main binding agents. This type of concrete has been extensively used to construct support layers for shallow footings and road backfills in some warm regions. So far, there has been no systematic research conducted to investigate the mechanical characteristics of polyamide fiber-reinforced LCC. To address this gap, LCC specimens were prepared with 0%, 0.5%, 1%, and 2% of polyamide fibers (a synthetic textile made of petroleum-based plastic polymers). Specimens were then cured for 3, 7, and 28 days at room and oven temperatures. Then, the effects of the fibers’ contents, curing conditions, and curing periods on the mechanical characteristics of LCC, such as secant modulus, deformability index, bulk modulus, shear modulus, stiffness ratio, strain energy, failure strain, strength ratio, and failure patterns, was investigated. The results of the unconfined compressive strength (UCS) tests showed that specimens with 1% fiber had the highest UCS values. The curing condition and curing period had significant effects on the strength of the LCC specimens, and oven-cured specimens developed higher UCS values. The aforementioned mechanical properties of the LCC specimens and the ability of the material to absorb energy significantly improved when the curing period under the oven-curing condition was increased, as well as through the application of fibers in the mix design. Based on the test results, a simple mathematical model was also established to forecast the mechanical properties of fiber-reinforced LCC. It is concluded that the use of polyamide fibers in the mix design of LCC can both improve mechanical properties and perhaps address the environmental issues associated with waste polyamide fibers.

Risk assessment of microplastics in fish assemblage based on ecological preferences in an interconnected and polluted river system

Risk assessment of microplastics (MPs) contamination in the assemblage of 15 important fish species with different feeding habits and microhabitats was studied in the River Ravi, Pakistan. Fishes with different feeding habits (omnivore, herbivore, and carnivore) and microhabitat preferences (surface, column, and bottom dweller) were sampled at Balloki and Sidhnai barrages during the post-monsoon seasons of 2019–2020. The gastrointestinal tract (GIT) of fish samples were found to be contaminated with MPs, with an average of 28.1 ± 20.7 MPs/individual and 26.8 ± 15.9 MPs/individual at Balloki and Sidhnai barrages, respectively. The surface dweller fish exhibited the highest MPs abundance, followed by the bottom dweller and column dweller. In addition, the highest MPs recovered from the omnivore generalist feeding group as compared to herbivores and carnivores. The fibers were the most abundant shape and generally made up of polyethylene terephthalate (PET) and polyethylene (PE). These PET and PE (low-density MPs) exhibit low hazard level, whereas high-density MPs with high hazard level and rarely present in GIT of sampled fishes. Based on MP polymer toxicity assessment, nine fish species were categorized in minor risk, two species in medium risk, and four species in highrisk group. Bottom dwelling fishes were at the highest plastic polymer risk level III due to the presence of a high density of MPs with high toxicity hazards. The high-risk prone fishes are under direct threat from MPs pollution, which may disrupt the ecological integrity of the river ecosystem and human health. The findings of the current study highlight the urgent need to address plastic pollution issues in River Ravi, and will be helpful for managers, researchers, and fisheries experts to mitigate this emerging challenge.speciesspecies

Applying Design of Experiments on the Mechanical Properties of Mefenamic Acid-Loaded Transdermal Films

The Design-Expert® program version 11 was used to analyze and optimize the mechanical properties of mefenamic acid-loaded transdermal films. The dependent variables were ultimate tensile strength (UTS), elongation at break and folding endurance, whereas the independent variables were silicone rubber, mefenamic acid and dibutyl sebacate (DBS). While quadratic models predicted elongation at break and folding endurance more accurately, a linear model predicted the highest correlation relationship for UTS. The design of experiments (DOE) estimated that the optimal silicone rubber, mefenamic acid and DBS ratio would be 5.3:2.5:5.2. By demonstrating that the prediction value of the ratio was more than 4, the model was proved to be suitable for forecasting results inside the design space without the requirement for additional trials. Experimental values of UTS, elongation at break and folding endurance were 6.20 ± 0.50 MPa, 711.22 ± 102.00 % and 857 ± 64 folds, respectively. The percent error was determined to be 8.50, 6.70 and 9.28 %, respectively. The DOE successfully demonstrated a low percent error of prediction (less than 10 %) from the Design-Expert® approach, which was satisfactory and accepted for preparation in drug delivery systems. HIGHLIGHTS Transdermal film formulations containing mefenamic acid had been optimized and enhanced As polymer matrix and plasticizer, silicone rubber and dibutyl sebacate were utilized, respectively While quadratic models predicted more correctly elongation at break and folding endurance, a linear model predicted the greatest correlation relationship for ultimate tensile strength Ultimate tensile strength, elongation at break and folding endurance experimental values were 20 ± 0.50 MPa, 711.22 ± 102.00 % and 857 ± 64 folds, respectively Less than 10 % was successfully demonstrated, which was enough and acceptable GRAPHICAL ABSTRACT

Polystyrene microplastics biodegradation by gut bacterial Enterobacter hormaechei from mealworms under anaerobic conditions: Anaerobic oxidation and depolymerization

Synthetic plastic is used throughout daily life and industry, threatening organisms with microplastic pollution. Polystyrene is a major plastic polymer and also widely found sources of plastic wastes and microplastics. Here, we report that Enterobacter hormaechei LG3 (CP118279.1), a facultative anaerobic bacterial strain isolated from the gut of Tenebrio molitor larvae (mealworms) can oxidize and depolymerize polystyrene under anaerobic conditions. LG3 performed biodegradation while forming a biofilm on the plastic surface. PS biodegradation was characterized by analyses of surface oxidation, change in morphology and molecular weights, and production of biodegraded derivative. The biodegradation performance by LG3 was compared with PS biodegradation by Bacillus amyloliquefaciens SCGB1 under both anaerobic and aerobic conditions. In addition, through nanopore sequencing technology, we identified degradative enzymes, including thiol peroxidase (tpx), alkyl hydroperoxide reductase C (ahpC) and bacterioferritin comigratory protein (bcp). Along with the upregulation of degradative enzymes for biodegradation, changes in lipid A and biofilm-associated proteins were also observed after the cells were incubated with polystyrene microplastics. Our results provide evidence for anaerobic biodegradation by polystyrene-degrading bacteria and show alterations in gene expression patterns after polystyrene microplastics treatment in the opportunistic pathogen Enterobacter hormaechei.

Spatial distribution of anthropogenic particles and microplastics in a meso-tidal lagoon (Arcachon Bay, France): A multi-compartment approach

Assessment of microplastic (MP) contamination is still needed to evaluate this threat correctly and tackle this issue. Here, MP contamination was assessed for a meso-tidal lagoon of the Atlantic coast (Arcachon Bay, France). Sea surface, water column, intertidal sediments and wild oysters were sampled. Five different stations were studied to assess the spatial distribution of the contamination. Two were outside of the bay and three were inside the bay (from the inlet to the back). A distinction was made between all anthropogenic particles (AP, i.e. visually sorted) and MP (i.e. plastic polymer confirmed by ATR-FTIR spectroscopy). The length of particles recovered in this study ranged between 17 μm and 5 mm. Concentration and composition in sea surface and water column samples showed spatial variations while sediment and oyster samples did not. At outside stations, the sea surface and the water column presented a blended composition regarding shapes and polymers and low to high concentrations (e.g. 0.16 ± 0.08 MP.m−3 and 561.7 ± 68.5 MP.m−3, respectively for sea surface and water column), which can be due to coastal processes and nearby input sources. The inlet station displayed a well-marked pattern only at the sea surface. High AP and MP concentrations were recorded, and fragments along with polyethylene overwhelmed (respectively 76.0 % and 73.2 %). Higher surface currents could explain this pattern. At the bay back, AP and MP concentrations were lower and fibers were mainly recorded. Weaker hydrodynamics in this area was suspected to drive this contamination profile. Overall, fragments and buoyant particles were mainly detected at the sea surface while fibers and negatively buoyant particles prevailed in other compartments. Most of the studied samples presented an important contribution of fiber-shaped particles (from 31.5 % to 94.2 %). Finally, contamination was ubiquitous as AP and MP were found at all stations in all sample types.

A New Remote Hyperspectral Imaging System Embedded on an Unmanned Aquatic Drone for the Detection and Identification of Floating Plastic Litter Using Machine Learning

This paper presents a new Remote Hyperspectral Imaging System (RHIS) embedded on an Unmanned Aquatic Drone (UAD) for plastic detection and identification in coastal and freshwater environments. This original system, namely the Remotely Operated Vehicle of the University of Littoral Côte d’Opale (ROV-ULCO), works in a near-field of view, where the distance between the hyperspectral camera and the water surface is about 45 cm. In this paper, the new ROV-ULCO system with all its components is firstly presented. Then, a hyperspectral image database of plastic litter acquired with this system is described. This database contains hyperspectral data cubes of different plastic types and polymers corresponding to the most-common plastic litter items found in aquatic environments. An in situ spectral analysis was conducted from this benchmark database to characterize the hyperspectral reflectance of these items in order to identify the absorption feature wavelengths for each type of plastic. Finally, the ability of our original system RHIS to automatically recognize different types of plastic litter was assessed by applying different supervised machine learning methods on a set of representative image patches of marine litter. The obtained results highlighted the plastic litter classification capability with an overall accuracy close to 90%. This paper showed that the newly presented RHIS coupled with the UAD is a promising approach to identify plastic waste in aquatic environments.

Synthesis and characterization of Eugenol-Trithiol-Methylenebisacrylamide and Eugenol-Trithiol-Allyeugenol copolymers for antibacterial food packaging

ABSTRACT The bacteria-resistant plastic polymer industry is growing rapidly due to promising research on food contamination. The thiol-ene copolymers Eugenol-Trithiol Methylenebisacrylamide (E3TMBA) and Eugenol-Trithiol, Allyl Eugenol (E3TAE) were synthesized via photopolymerization. Both copolymers possess high thermal stability, which is crucial for maintaining their durability when used with high-temperature foods. The copolymers demonstrated a 5.0% mass loss (T5) at 179°C for E3TMBA and 255.9°C for E3TAE, as well as the formation of ash products at above 500°C. Both copolymers have mechanical properties and exhibit antibacterial activity against Escherichia coli and Staphylococcus aureus, enhancing their food packaging potential.

Numerical investigation of the three-dimensional paths of plastic polymers in the Gulf of Naples

The high-resolution Campania Regional Ocean Model (CROM), coupled with an online Lagrangian particle tracking algorithm, is used to investigate the horizontal and vertical behavior of different (in terms of size and density) plastic polymer types during February and August 2016 in the Gulf of Naples. The transport of passive particles is evaluated based on the three-dimensional Eulerian velocity fields provided by the ocean model. The virtual particles are released in several hot spot areas in the Gulf of Naples where most of the marine debris is supposed to come from. A sensitivity analysis on the vertical sinking for negatively buoyant particles is carried out. The sinking behavior is determined by the settling velocity, which depends on the physical properties of the individual litter item as well as on the hydrodynamical features of the marine environment. Different numerical experiments are carried out to evaluate the effect of marine dynamics on three-dimensional transport.

Comparative analysis of tensile properties on thermoplastic & thermosetting polymer composites

Polypropylene and polyester polymer were used to create the specimens, which were then reinforced with glass fibres. Both the polyester and the polypropylene polymer's composition impacts and tensile qualities were compared and evaluated. In this research, the comparison of thermoplastic and thermosetting plastic material specimens from the above-mentioned proposal and show how they differ from polypropylene in their use of hand wet layup techniques of polyester resin with glass fibre. One synthetic fibre that offers excellent thermal, electrical, and corrosion resistance is made of glass fibres. One thermosetting substance that has great bonding properties is polyester resin. One of the thermoplastic materials that is often durable, reusable, and flexible is polypropylene. This study's findings demonstrate that thermosetting plastic materials have superior tensile characteristics than thermoplastic plastic polymers.