Plasticizer Content Research Articles

Quantification and polymeric characterization of microplastics in composts and their accumulation in lettuce

Organic fertilizers have become a vector for the transport of microplastics (MPs), which pose human health concerns through the food chain. This study aimed to quantify and characterize MPs in eight different compost samples of various raw materials and their subsequent translocation to lettuce (Lacuta sativa) grown on contaminated composts. The results revealed that the MP abundance ranged from 3810 to 16530 MP/kg. Municipal solid waste compost (MSWC) had highest abundance (16082 ± 632 MP/kg), followed by leaf compost (LC) and organic compost (OC) (6299 ± 1011 and 3680 ± 419 MP/kg, respectively). MPs of <100 μm in size were most dominant in MSWC and LC. Fragments and fibers were the prevalent shape types, with white/transparent colored MPs being more abundant. Polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were the dominant polymers. MPs accumulation in the lettuce leaves was greatest in the lettuce plants grown on MSWC, followed by those grown on LC and OC, indicating that MSWC grown lettuce is not suitable for human consumption. The decrease in the growth (leaf length, number of leaves, leaf fresh and weights) and physiological (membrane stability index, relative water contents) parameters of lettuce was in line with the trend of MP accumulations. Hence, it is highly important to regulate the plastic contents in compost because it is a threat to ecosystems and human health.

Ecological risk assessment of microplastics and mesoplastics in six common fishes from the Bay of Bengal Coast

Plastic particles have emerged as a growing threat to both ecosystems and human well-being, as they are being ingested and accumulate at different trophic levels. However, microplastic and mesoplastic contamination and its risk to coastal and marine water fish have not been well studied, particularly in the northern Bay of Bengal. In this study, the presence of small-scale plastic particles (micro- and meso-sized) in the gastrointestinal tract (GIT) and muscles of six edible fish species from the northern Bay of Bengal Coast were identified and analyzed. The overall range of microplastics was 1.74 ± 0.23–3.79 ± 2.03items/g in muscle and 0.54 ± 0.22–5.96 ± 3.16 items/g in the GIT, with 16.38 ± 8.08–31.88 ± 12.09 items/individual. No mesoplastics were found in muscle tissue, but they were present in the GIT at concentrations ranging from 0.33 ± 0.27 to 0.03 ± 0.02 items/g and from 0.51 ± 0.05to 1.38 ± 1.01 items/individual. Lepturacanthus savala accumulated the most microplastics in muscle, and Harpadon nehereus had the least. In addition, the highest levels of mesoplastics were detected in the GIT of Polynemus paradiseus and the lowest was detected in the GIT of Lutjenus sanguineus. Omnivorous fish showed higher plastic concentrations than carnivorous fish, which was linked to dietary habits, feeding strategies and digestive processes. Plastic material predominantly accumulated in the GIT rather than in the muscle. The majority of ingested plastic particles were fibres (95.18 %), were violet in color (34 %), and were < 0.5 mm in size (87 %). The dominant microplastic polymers included 38 % PE, 15 % PP, 33 % PU, and 14 % CES. In contrast, the prevalent mesoplastic polymers comprised 45 % PE, 19 % PP, 13 % PS, 16 % PA, and 7 % PET. Subsequently, a hazard analysis using the polymer hazard index (PHI) revealed that plastic contamination was of distinct hazard categories for different polymer types, ranging from grade I (<1) to grade IV (100−1000). The assessment of the contamination factor (1 < CF < 3) and pollution load index (PLI > 1) indicated moderate contamination of fish by the ingestion of plastic debris. This study provides the foremost evidence for the presence of mesoplastics and microplastics in coastal and marine fish in the study region, paving the way for future investigations and policy implementation.

Combustion characteristics of refuse-derived fuel pellets having varying plastic compositions.

The plastic fraction of refuse-derived fuel (RDF) pellets influences fuel's physico-chemical, and mechanical properties, which in turn might affect the combustion behavior of RDF. In the present study, the combustion behavior of different plastic fraction-simulated RDF pellets is reported. The simulated pellets were prepared based on the Indian commercial RDF composition. Initially, the plastic content varied from the existing fraction in Indian commercial RDF, i.e., 35% (RDF-1), to a lower plastic content of 5% (RDF-2). Physico-chemical characterization showed that a higher plastic fraction in RDF-1 reduces its pellet density by 25% as compared to RDF-2. The changes in RDF physico-chemical properties due to plastic variation are reflected in the RDF conversion process. Single-particle and packed-bed studies concluded that the lower density for higher plastic RDF-1 leads to lower conversion times (36%), and higher flame front speed (11%), which are desirable conditions for faster conversion. However, packed-bed studies also showed limitations regarding the utilization of high plastic RDF as RDF-1 has a narrow range of operating air mass flux due to the early advent of convective cooling of the bed. Finally, considering the constraints associated with the utilization of high plastic fraction (~ 35%) RDF and to maximize the effective utilization of plastic in RDF, a workable plastic fraction of 15% in RDF was proposed and tested for its combustion properties. RDF with 15% plastic showed faster conversion, higher flame front speed, and a wider range of operating air mass flux before the advent of convective cooling of the bed.

Formulation of Saxagliptin Oral Films: Optimization, Physicochemical Characterization, In-Vivo Assessment, and In-Vitro Real-Time Release Monitoring via a Novel Polyaniline Nanoparticles-Based Solid-Contact Screen Printed Ion-Selective Electrode

Oral dispersible films have received broad interest due to fast drug absorption and no first-path metabolism, leading to high bioavailability and better patient compliance. Saxagliptin (SXG) is an antidiabetic drug that undergoes first-path metabolism, resulting in a less active metabolite, so the development of SXG oral dispersible films (SXG-ODFs) improves SXG bioavailability. The formula optimisation included a response surface experimental design and the impact of three formulation factors, the type and concentration of polymer and plasticiser concentration on in-vitro disintegration time and folding endurance. Two optimised SXG-ODFs prepared using either polyvinyl alcohol (PVA) or hydroxypropyl methylcellulose were investigated. SXG-ODFs prepared with PVA demonstrated a superior rapid disintegration time, ranging from 17 to 890 s, with the fastest disintegration time recorded at 17 s. These short durations can be attributed to the hydrophilic nature of PVA, facilitating rapid hydration and disintegration upon contact with saliva. Additionally, PVA-based films displayed remarkable folding endurance, surpassing 200 folds without rupture, indicating flexibility and stability. The high tensile strength of PVA-based films further underscores their robust mechanical properties, with tensile strength values reaching up to 4.53 MPa. SXG exhibits a UV absorption wavelength of around 212 nm, posing challenges for traditional quantitative spectrophotometric analysis, so a polyaniline nanoparticles-based solid-contact screen-printed ion-selective electrode (SP-ISE) was employed for the determination of SXG release profile effectively in comparison to HPLC. SP-ISE showed a better real-time release profile of SXG-ODFs, and the optimised formula showed lower blood glucose levels than commercial tablets.Graphical

Discontinuous Shear Thickening of Suspensions of Magnetic Particles in Relation to the Polymer Coating on Their Surfaces

The phenomenon of discontinuous shear thickening (DST) is observed in suspensions of solid particles with a very high-volume fraction. It is characterized by an abrupt decrease in the shear rate for critical stress during a ramp of stress. This behavior can be reproduced in numerical simulations by introducing a local friction between two particles above a given local force. We present experimental results showing this DST behavior obtained with suspensions of magnetic (iron) and nonmagnetic (calcium carbonate) particles and different amounts of a superplasticizer molecule used in the cement industry. For both types of particles, the same behavior was observed with first an increase in critical stress with the amount of plasticizer followed by a decrease at higher concentrations but with a larger viscosity before critical stress was reached. At a low concentration of plasticizer, the low critical stress is interpreted by the local sliding of plasticizer molecules on the surface of particles. At higher concentrations, when total coverage is achieved, the critical stress is higher since it has to remove the molecules out of the surface. At still higher concentrations, the increase in viscosity is explained by the formation of multilayers of molecules on the surface of the particles. This interpretation is supported by the measurement of the adsorption isotherm of the plasticizer on the surface of the particles.

Composite Materials as the Basis of Concrete Canvas

Statement of the problem. Composite materials based on mineral components and organic and mineral systems are gradually expanding their presence in the domestic market of materials and building techno-logies. Concrete fabric, as one of the varieties of textile-concrete, can be considered as a composite material whose properties depend both on those of polymeric materials that form its enclosing surfaces and those of the core material, and on the nature of the interaction between the facing and core materials. The purpose of the research presented in the article is to evaluate the main strength characteristics of the concrete canvas, as well as to study the effect of the content of Portland cement, plasticizer and modifying additive on the properties of fine-grained concrete as the basis of the concrete canvas, as well as to evaluate the possible areas of application of the concrete canvas with the obtained properties. Results. In the process of processing the results of the experiment and analytical optimization of the response functions, the fundamentals of the methodology for selecting the composition of modified fine-grained concrete as the basis of the concrete canvas were developed. As a result of the tests, the following characteristics of the material were established: average density ––1450––1500 kg/m3; compressive strength –– not less than 36––38 MPa, puncture strength –– not less than 3 kN; ultimate strength in ben-ding 16––20 MPa. Conclusions. Despite the fact that the thickness of the concrete canvas in the hardened state does not exceed 10 mm, its properties are not inferior to those of other types of textile concrete, i.e., they have high strength characteristics with a relatively small thickness. The most promising areas of application of the concrete canvas are the repair and waterproofing of reinforced concrete structures of hydraulic structures, and the strengthening of slopes.

Propellant Free Pressurized Spray System of Etodolac to Manage Acute Pain Conditions: In Vitro and In Vivo Evaluation.

This study aimed to develop a propellant-free topical spray formulation of Etodolac (BCS-II), a potent NSAID, which could be beneficial in the medical field for the effective treatment of pain and inflammation conditions. The developed novel propellant-free spray formulation is user-friendly, cost-effective, propellant-free, eco-friendly, enhances the penetration of Etodolac through the skin, and has a quick onset of action.Various formulations were developed by adjusting the concentrations of different components, including lecithin, buffering agents, film-forming agents, plasticizers, and permeation enhancers. The prepared propellant-free spray formulations were then extensively characterized and evaluated through various in vitro, ex vivo, and in vivo parameters. The optimized formulation exhibits an average shot weight of 0.24 ± 0.30ml and an average drug content or content uniformity of 87.3 ± 1.01% per spray. Additionally, the optimized formulation exhibits an evaporation time of 3 ± 0.24min. The skin permeation study demonstrated that the permeability coefficients of the optimized spray formulation were 21.42cm/h for rat skin, 13.64cm/h for mice skin, and 18.97cm/h for the Strat-M membrane. When assessing its potential for drug deposition using rat skin, mice skin, and the Strat-M membrane, the enhancement ratios for the optimized formulation were 1.88, 2.46, and 1.92, respectively against pure drug solution. The findings from our study suggest that the propellant-free Etodolac spray is a reliable and safe topical formulation. It demonstrates enhanced skin deposition, and improved effectiveness, and is free from any skin irritation concerns.

Microplastics in human blood: Polymer types, concentrations and characterisation using μFTIR

Microplastics (MPs) are an everyday part of life, and are now ubiquitous in the environment. Crucially, MPs have not just been found within the environment, but also within human bodies, including the blood. We aimed to provide novel information on the range of MP polymer types present, as well as their size and shape characteristics, in human whole blood from 20 healthy volunteers. Twenty-four polymer types were identified from 18 out of 20 (90 %) donors and quantified in blood, with the majority observed for the first time. Using an LOQ approach, five polymer types met the threshold with a lower mean ± SD of 2466 ± 4174 MP/L. The concentrations of plastics analysed in blood samples ranged from 1.84 − 4.65 μg/mL. Polyethylene (32 %), ethylene propylene diene (14 %), and ethylene–vinyl-acetate/alcohol (12 %) fragments were the most abundant. MP particles that were identified within the blood samples had a mean particle length of 127.99 ± 293.26 µm (7–3000 µm), and a mean particle width of 57.88 ± 88.89 µm (5–800 µm). The MPs were predominantly categorised as fragments (88 %) and were white/clear (79 %). A variety of plastic additive chemicals were identified including endocrine disrupting-classed phthalates. The procedural blank samples comprised 7 polymer types, that were distinct from those identified in blood, mainly resin (25 %), polyethylene terephthalate (17 %), and polystyrene (17 %) with a mean ± SD of 4.80 ± 5.59 MP/L. This study adds to the growing evidence that MPs are taken up into the human body and are transported via the bloodstream. The shape and sizes of the particles raise important questions with respect to their presence and associated hazards in terms of potential detrimental impacts such as vascular inflammation, build up within major organs, and changes to either immune cell response, or haemostasis and thrombosis.

Constructing in-situ polymerized electrolyte for room-temperature solid-state chloride ion battery with enhanced electrochemical performance

Considering large volume variation and dissolution issues of some promising electrode materials for chloride ion batteries (CIB), the construction of solid polymer electrolytes (SPE) for efficient chloride ion transport is intriguing. However, this is hindered by low ionic conductivity of chloride SPEs and poor cycling performance of CIBs. Herein, an in-situ polymerized and cross-linked poly(ethylene glycol) diacrylate-based chloride SPE with a low plasticizer content of succinonitrile is designed, yielding a room-temperature ionic conductivity of 7.6 × 10−5 S cm−1, which is higher than that of previously reported SPEs for CIBs. Moreover, the use of the as-prepared SPE achieves an integrated organic cathode with significantly enhanced rate performance and capacity retention of 96.1 % after 100 cycles at room temperature, which is much higher than 49.9 % (80 cycles) of the cathode in the CIB with a sandwiched structure. These improved properties are also superior to that of other reported cathodes coupled with different chloride SPEs. The chloride ion transfer mechanism of the cathode is revealed by X-ray photoelectron spectroscopy and energy dispersive spectroscopy.

DESIGN AND OPTIMIZATION OF ESCITALOPRAM OXALATE ORAL DISSOLVING FILMS BY RESPONSE SURFACE METHODOLOGY

Objective: To develop and optimise the oral dissolving films of escitalopram oxalate by response surface methodology. Methods: Oral dissolving film compositions were optimized by central composite design. The films are prepared by solvent casting method. Initially, different polymers were screened and based on the results polyvinyl alcohol was selected as polymer, propylene glycol was selected as plasticizer. Concentration of polymer and concentration of plasticizer were fixed as independent variables; tensile strength, percent elongation, elastic modulus and amount dissolved up to 5 min (%D5 min) were taken as responses. Results: The prepared films exhibited good surface characteristics. The thickness, uniformity of weight, surface pH and drug content are within acceptable range. The mechanical properties like tensile strength, folding endurance, percent elongation and elastic modulus were determined. The statistical analysis showed that polymer concentration has a positive effect on disintegration time and the plasticizer concentration has a significant effect on folding endurance. The prepared film relesases nearly 95% at the end of 5 min. The design space was used to optimize the quantities of polymer and plasticizer. The comparison of checkpoint experiment batch responses are corelating with the predicted responses. Conclusion: Escitalopram oxalate oral dissolving films was successfully designed and optimized by response surface method. It was concluded that the prepared films exhibit good mechanical properties and maximum release within 10 min.

Nectar and floral morphology differ in evolutionary potential in novel pollination environments.

Plants can evolve rapidly after pollinator changes, but the response of different floral traits to novel selection can vary. Floral morphology is often expected to show high integration to maintain pollination accuracy, while nectar traits can be more environmentally sensitive. The relative role of genetic correlations and phenotypic plasticity (PP) in floral evolution remains unclear, particularly for nectar traits, and can be studied in the context of recent pollinator changes. Digitalis purpurea shows rapid recent evolution of corolla morphology but not nectar traits following a range expansion with hummingbirds added as pollinators. We use this species to compare PP, heritability, evolvability and integration of floral morphology and nectar in a common garden. Morphological traits showed higher heritability than nectar traits, and the proximal section of the corolla, which regulates access to nectar and underwent rapid change in introduced populations, presented lower integration than the rest of the floral phenotype. Nectar was more plastic than morphology, driven by highly plastic sugar concentration. Nectar production rate showed high potential to respond to selection. These results explain the differential rapid evolution of floral traits previously observed in this species and show how intrafloral modularity determines variable evolutionary potential in morphological and nectar traits.

Resonant mechanical vibration of a polymer PVC film under modulated optical excitation

The mechanical response of plasticized thin PVC films under a modulated optical radiation pressure excitation is investigated as a function of the plasticizer content. A resonant behavior with different quality factor depending on the plasticizer content is investigated. The higher the content, the larger the resonant width. A significant thinning of the film is observed, whatever the plasticizer content. The surface tension of the air/solid interface is extracted and shown to hardly vary. The loss factor which is known as the ratio of dissipated energy to stored energy is, on the other hand, dependent on the plasticizer content. In particular, the optical studies reveal that all the energy is always stored at the film interfaces with a dissipation described by the well-known loss factor E′′ of the Young’s modulus.

The impact of plasticisers on crystal nucleation, growth and melting in linear polymers

Plasticisers are often added to crystallising polymers to improve their processability. Despite many experimental studies, very few modelling studies have been performed to provide fundamental understanding of the impact of plasticisers on polymer cyrstallisation kinetics and thermodynamics. In this work, molecular dynamics simulations are used to study crystallisation in a model linear polymer with plasticiser. We first demonstrate that the plasticiser lowers the amorphous phase glass transition, with the extent of the effect increasing with plasticiser concentration, due to increased polymer mobility. Using a model filler surface to induce crystallisation, we find that the plasticiser also reduces crystallisation and melting temperatures. Furthermore, we find that the plasticiser is expelled from the crystals during growth so that its concentration in the amorphous matrix increases with degree of crystallisation. This has a pronounced consequence for crystal melting, and we find a broad temperature range where the crystal is in equilibrium with the amorphous phase, which we rationalise in terms of free energy changes. This has potentially important consequences for the processing of linear polymers such as polyhydroxybutyrate (PHB), poly(l-lactic acid) (PLLA) and polyvinyl alcohol (PVA), by providing the opportunity for processing the polymer in a semicrystalline rather than fully amorphous state.

Removal of Methylene Blue Dye from Aqueous Solutions Using Polymer Inclusion Membrane Containing Calix[4]pyrrole.

The effective purification of aqueous solutions of methylene blue dye was tested using polymer inclusion membranes (PIMs) that contained cellulose triacetate (CTA) as a polymer base, o-nitrophenyl octyl ether (o-NPOE) as a plasticizer, and meso-tetra methyl tetrakis-[methyl-2-(4-acetlphenoxy)] calix[4]pyrrole (KP) as a carrier. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy were used to define the microstructure and surface of PIMs. Experimental results showed that, with an increased concentration of methylene blue in an aqueous solution, the removal percentage also increased. Further observation showed that the flux increased with the rise in the source phase pH values from 3 to 10. The carrier and plasticizer content in the membrane significantly influenced the membrane's transport properties. The optimal composition of the membrane in percent by weight for KP was 74% plasticizer; 18% support, and 8% carrier. The maximum MB removal (93.10%) was achieved at 0.10 M HCl solution as the receiving phase. It was shown that the membrane with optimal composition showed good reusability and enabled the easy and spontaneous separation of methylene blue from aqueous solutions.

Studi Eksprimental Dengan Metode Marshall Pemanfaatan Plastik Polystyrene Sebagai Bahan Aspal AC-BC

Polystyrene plastic waste is difficult to decompose naturally and becomes microplastics which pollute the environment. Therefore, plastic waste is utilized in road pavement mixtures. This research aims to find out whether the addition of Polystyrene to AC-BC asphalt with levels of 4% and 5% can improve the quality of asphalt based on the 2018 General Bina Marga specifications. This research was carried out in a laboratory and analyzed using the Marshall method. AC-BC asphalt test results with polystyrene content of 4% and 5%, show that only the VIM value at 4% plastic content with a value of 3.88% meets and 5% plastic content with a value of 2.58% does not meet the range of 3%-5%. , then apart from the VIM value of AC-BC asphalt it meets the specifications. Keywords: AC-WC, AC-BC, Polystyrene, Marshall

Effect of stabilizing subgrade layer using various additives on the flexible pavement design

Soil stabilization involves enhancing the physical properties of soil to increase its stability, durability, and ability to support heavy loads, making it a crucial technique in civil engineering and construction. The process is used to reduce soil permeability and compressibility and increase its shear strength. To achieve this, various additives are used. This paper evaluates RoadCem (nanomaterial) and traditional additives such as cement, lime, and ashes materials such as rice husk ash (RHA) and fly ash (FA) as by-product materials in clayey soil stabilization. The used percentages of Lime were (2, 4, 6, and 8%), cement and RoadCem (3, 6, 9, and 12%), FA (3, 6, 9, 12, and 15%), and RHA (5, 10, 15, 20, and 25%) by dry weight of the tested soil. Various tests were used to examine and evaluate the physical and engineering characteristics of the treated soil, modified proctor, atterberg limits, free swelling (FS%), unconfined compressive strength (UCS), California bearing ratio (CBR), and resilient modulus (Mr) as well as microstructure tests [scanning electron microscopic (SEM)]. All admixtures were tested and subjected to two curing periods, 7 and 28 days. The results indicated that the optimum additives percentages were selected as 6% FA and 15% RHA activated by 6% lime and 6% for both RoadCem and cement. At these percentages, plasticity, FS%, and optimum moisture content (OMC) values were decreased. In contrast, maximum dry density (MDD), UCS, CBR%, and Mr values were increased. In addition, the correlation between Mr and both CBR and UCS was drawn. SEM results showed that major changes were observed in the microstructure of treated samples due to the forming of cementitious materials. The study evaluated the effect of subgrade stabilization on reducing base layer thickness under light, medium, and heavy expected traffic loads with an economic analysis to examine the benefits of subgrade stabilization. The cost analysis showed that the optimal economic additives were RoadCem and cement.

Submission to Journal of Polymers and the Environment Evaluation of Thermal Properties and Crystallinity in PHB-Based Systems – A DoE Approach

Complex formulations based on poly(hydroxybutyrate) (PHB) and poly(hydroxybutyrate-co-valerate) (PHBV) were studied to statistically assess the effect of formulation (i.e., hydroxyvalerate (HV) content, plasticiser chemistry and content, filler type and content) on their thermal properties and degree of crystallinity (Xc). In binary systems, thermal properties were mainly influenced by filler type rather than its content, while for plasticised systems the changes were dependent on both increasing plasticiser content and PHB-plasticiser compatibility. Variations in HV content affected the ability of the polymer chain to fold, leading to significant changes in both thermal properties and Xc. In ternary systems, presence of multiple additives and consequent changes in intermolecular interactions lead to multifaceted behaviours that were not easily predicted by results from binary systems alone. For example, melting temperature did not show dependence on filler presence in PHBV systems despite introducing variations in pure PHB systems. In general, thermal properties and Xc are affected by all parameters studied, with changes in system free volume (i.e. changes in HV content and plasticisation) playing the most significant role. These results expand the understanding of factors controlling crystallisation in complex polymer systems and can be used to control matrix properties in new generations of packaging materials.

Structural, Mechanical, and Barrier Properties of the Polyvinylidene Fluoride-Bacterial Nanocellulose-Based Hybrid Composite.

This study presents an analysis of films which consist of two layers; one layer is PVDF as the matrix, along with fillers BaTiO3 (BT), and the second is one bacterial nanocellulose (BNC) filled with Fe3O4. The mass fraction of BT in PVDF was 5%, and the samples were differentiated based on the duration of the mechanical activation of BT. This innovative PVDF laminate polymer with environmentally friendly fillers aligns with the concept of circular usage, resulting in a reduction in plastic content and potential improvement of the piezoelectric properties of the entire composite. This work presents new, multifunctional "green" packaging materials that potentially could be a good alternative to specific popular materials used for this purpose. The synthesis of the films was carried out using the hot press method. Tensile tests, water vapor permeability examination, and structural analyses using SEM-EDS and FTIR have been conducted. The sample PVDF/BT20/BNC/Fe3O4 exhibited the best barrier properties (impermeability to water vapor), while the highest tensile strength and toughness were exhibited by the PVDF/BT5/BNC/Fe3O4 sample.

Towards the toughness-strength balance of poly(vinyl alcohol) films via synergic plasticization

Polyvinyl alcohol (PVA) films have significant rigidity due to the large number of hydrogen bonds within and between molecular chains. This feature hinders their industrial applications. Small molecule plasticizers can effectively improve the toughness of PVA films. However, this improvement decreases their modulus and strength. In this study, the effect of individual plasticizer, namely, diethanolamine (DEA), glycerol (GLY), and H2O, on the mechanical properties was first studied. It was found that adding an individual plasticizer increase the toughness but decrease the modulus for all the three plasticized PVA films, with DEA decreased least. Then, the property changes caused by of H2O and plasticizer content in two synergic plasticizing systems of DEA/H2O and GLY/H2O were systematically investigated and compared to demonstrate further the different effects of DEA and GLY on the toughness and modulus of the PVA film. Results indicated that the modulus and toughness of PVA casted film with a 10% DEA content improved after the addition of 3% H2O for the DEA/H2O plasticizing system. Despite a large improvement in toughness, the strength was always largely reduced with the increase in H2O or GLY content for the GLY/H2O system. The infrared spectrum results showed that H2O could be physically combined with both PVA and DEA to construct a cross-linked hydrogen bond network, because of the relatively strong electronegativity of the N atom in DEA. However, forming such a cross-linked hydrogen bond network in the GLY/H2O system is difficult. Thus, only a plasticizing effect was observed in the PVA/GLY/H2O films. Our work provides a better understanding of the effects of plasticizer and H2O on the hydrogen bonding and properties of PVA films to achieve toughness-strength balance via synergic plasticization.

Plastic roads: asphalt mix design and performance

Plastic materials are extensively utilized in various aspects of daily life. However, the substantial amount of plastic waste generated can cause significant global environmental issues without efficient waste management practices. To address this problem, the utilization of waste plastics in high-value applications such as highway construction through hot mix asphalt (HMA) has been deemed ideal. Polyethylene terephthalate (PET), low-density polyethylene (LDPE), and high-density polyethylene (HDPE) are the three most prevalent types of plastic waste found in municipal solid waste. The impact of plastic-type and content on the mechanical, volumetric, and durability properties of hot mixed asphalt (HMA) was investigated by utilizing varying plastic contents of PET, LDPE, and HDPE. Tests were conducted in accordance with ASTM standards on twelve HMA mixtures made with an optimal binder content (OBC) of 4.3%, and plastic contents of 3%, 6%, 9%, and 12% by weight of OBC. Marshall stability and flow tests were conducted to ascertain the optimal plastic content for each tested mixture. The findings indicated that the stability and flow values improved as the plastic content was raised. 9% LDPE mix gave a maximum Marshal stability value of 12 kN. Additionally, as the plastic content increased, the values for air voids and voids filled with asphalt decreased in all 12 mixes tested. This research aligns with the United Nations 2030 sustainable development goals (SDGs), including SDGs 9, 11, 12, 13, 14, and 15, and presents a viable method for implementing the 3Rs approach towards sustainable plastic waste management.