Initial Polymer Research Articles

Synthesis and Characterization of Shungite Modified Poly-N-Ninylpyrrolidone-Agarose Composites for Medical Application.

A systematic investigation was conducted to synthesize hybrid composite materials that use synthetic poly-N-vinylpyrrolidone and natural (agar-agar) macromolecules with plasticizers (PEG-400) and mineral filler shungite by means of electron irradiation. The XRD and SEM data showed that the structure of the resulting hybrid composites is an interpenetrating network with distributed particles of mineral component. It has been established that the mechanical properties of hybrid composites are determined mainly by the structural organization of the interpenetrating polymer network formed under electron irradiation of the initial synthetic and natural polymer mixture in the presence of plasticizers, as well as by the conditions for intercalation of polymer segments into the mineral matrix and vice versa. It has been revealed that the degree of swelling of hybrid composites strongly depends on the concentration of a low-molecular plasticizer in the polymeric interpenetrating network, which easily impregnates into the matrix of shungite. Successfully obtained [PVP-AA-PEG] hydrogels with shungite can be applied in regenerative medicine as wound healing dressings.

Prediction of the structure of polymer-coated cardboards produced by thermocompression using I-optimal design of experiment.

The production of contrasted polymer-coated cardboards is necessary to establish the structure/properties relationships and produce the « just necessary » packaging materials. For that purpose, the impact of the processing parameters on the resulting structure of polymer-coated cardboards was modeled using a statistical Design of Experiment (DOE) approach. Five independent factors were considered: three numeric continuous factors, the pressure, the temperature, and the duration of thermocompression, one numeric discrete factor, the initial polymer film thickness, and one categorical factor, the cardboard basis weight. Four responses were considered: the thicknesses of each of the three layers constituting polymer-coated cardboards (i.e., the free polymer, the impregnated, and the free cardboard) and the material’s curvature. The choice of the adequate DOE was first assessed using a Scoping Design and coupled with the characterization of the used polymer, i.e., poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV). The I-optimal DOE was found to be the most suitable and was therefore implemented. To validate the model, the DOE was then used to produce two targeted structures, one with no impregnation of the polymer and another one with a complete impregnation of the cardboard. The values of thicknesses and curvature were not significantly different from the model predictions, therefore verifying the model.

Insights on Adsorptive Property of Thermally Treated Smectite (Dioctahedral)

ABSTRACTThe use of clay in the field of mineral materials is directly impacted by its thermal stability and changes in microstructure and properties following heat and other treatments. Therefore, it is crucial to investigate how clay's composition and structure are changed with time or how its surface characteristics are changed because of heat treatment. In the current work, the effect of heat treatment on the adsorptive property of smectite clay under various conditions like initial polymer concentration and its molar mass, pH, and temperature variation has been investigated. Various techniques like X‐ray fluorescence spectrometry, thermal analysis, X‐ray diffraction, infrared spectroscopy, and scanning electron microscopy were used for the phase analysis and the structural features of the heat‐treated clay analysis. It was observed that the specific surface area of smectite gradually dropped as the preheating temperature was increased, and the phase composition and structure underwent significant changes. When clay is heated over 423 K, the adsorbed gases and water are forced off the surface, increasing the amount of free active sites, and smectite's adsorption potential was increased. By raising the polymer's initial concentration and molecular mass, the extent of adsorption was increased whereas it was decreased with the increase in pH. However, in the case of temperature, the adsorption was first increased and then decreased with the increase in temperature indicating a change in the chemical composition of the clay and hence the surface area.

STRUCTURES OF HDPE/GaAs AND HDPE/GaAs<Te> COMPOSITES IRRADIATED WITH GAMMA QUANTA

The results of optical studies of structural changes in composite HDPE/GaAs and HDPE/GaAs<Te> films irradiated with gamma quanta at doses of 100, 200, and 300 kGy at room temperature are presented. It was found that gamma irradiation of the initial polymer and their composite films leads to the formation of optical absorption bands at 220 and 280 nm, indicating the formation of C = 0 and C = C-bonds. It was established that composite HDPE/GaAs<Te> films are the most radiation-resistant in the absorbed dose range of 100…300 kGy.

Electron beam irradiation developed cinnamon oil- (polyvinyl alcohol/gum tragacanth)/graphene oxide dressing hydrogels: Antimicrobial and healing assessments

This study aimed to develop hydrogel dressings for wound healing composed of gum tragacanth (TG) and polyvinyl alcohol (PVA) loaded with Graphene oxide (GO) and Cinnamon oil (CMO) using electron beam irradiation. The impact of the preparation conditions and the incorporation of GO and CMO on the characteristic properties of the prepared CMO-(PVA/TG)-GO wound dressings was evaluated. The healing-related characteristics were assessed, including fluid absorption and retention, water vapor transmission rate (WVTR), hemolytic assay, and antimicrobial potential. Wound healing efficacy was evaluated using a scratch wound healing assay. FTIR analysis verified the chemical structure, whereas scanning electron microscopy demonstrated an appropriate porosity structure necessary for optimal wound healing. The gel content increases with the initial total polymer concentration and the irradiation dose increases. Higher GO and CMO content improve the gel content and decreases swelling. WVTR decreases with the rise in CMO content. In vitro, cytotoxicity and hemolytic potency assessments confirmed their biocompatibility. The incorporation of GO and CMO enhances the antimicrobial activity and wound-healing capability. Based on the above findings, CMO-(PVA/TG)-GO dressings show promising potential as candidates for wound care.

Effect of Heat Treatment on the Supramolecular Structure of Copolymers Based on Poly(propylene glycol fumarate phthalate) with Acrylic Acid

Previous studies investigating the thermal decomposition of p-PGFPh:AA copolymers in an inert atmosphere have provided only a general understanding of the changes that occur during thermolysis. Comprehensive studies are required to gain a better understanding of these processes [1]. The most comprehensive information on the influence of various factors on both the kinetics and the supramolecular structure of the resulting products can be obtained by combining the method of thermal analysis with IR, mass spectrometry, and scanning electron microscopy. The compounds studied have two different compositions, namely p‑PGFPh:AA 6.77:93.23 mol % and p-PGFPh:AA 86.67:13.33 mol %. These compounds were then subjected to a thermolysis process, which resulted in the emission of gases and a decrease in sample weight. The degradation process can be divided into three stages: 1) Depolymerization of the main chain; 2) Depolymerization of the side chain; 3) Final decomposition. These processes occur sequentially at different temperature ranges. According to TG- and DTG studies, complete decomposition of p-PGFPh:AA copolymers occurred at Tterm = 340–350 °C. In this temperature range, a slight loss of sample mass (less than 10 wt %) was observed along with a slight gas evolution. The main gaseous products from the transformation of the studied samples were CO and CO2. This was supported by IR-CO (2000–2200 cm−1) and CO2 (2310–2370 cm−1) as well as mass spectrometric observations. The final products resulting from the thermolysis of p-PGFPh:AA copolymers were examined under an electron microscope. The results showed a similar morphological pattern of mesostructures with sizes ranging from 0.3–1.5 μm, which were observed depending on the porous structure of the initial polymer material. Based on the experimental data, it can be concluded that the p-PGFPh:AA copolymers (in proportions of 6.77:93.23 mol % and 86.67:13.33 mol %) have a relatively high degree of resistance to heating and do not undergo any changes in chemical composition, particle size and shape. In conclusion, the results clearly indicate that the selection of conditions for pyrolysis plays a crucial role in increasing the thermal stability of polymeric materials. This method allows for purposeful changes in the structure and properties of polymers.

Drying-Induced Flash Nanoprecipitation in a Sessile Drop: A Route to Synthesize Polymeric Nanoparticles.

Flash nanoprecipitation is a simple and scalable method to produce nanoparticles by rapid mixing of a polymer solution with an antisolvent. High-speed mixing devices for the continuous synthesis of polymeric nanoparticles and drug-encapsulated nanoparticles have been designed. In this work, we demonstrate a different approach to induce flash nanoprecipitation using the differential evaporation of solvents in a sessile drop. To show proof of concept, we use polymethyl-methacrylate (PMMA) dissolved in a tetrahydrofuran (THF)-water mixture as a model system. A sessile drop of the polymer solution is allowed to dry under controlled conditions. The sessile drops of the PMMA-THF-water ternary mixture are observed to dry in the constant radius mode. As THF in the drop evaporates faster than water, PMMA supersaturates and precipitates as nanoparticles. Although coffee-ring formation is well-studied in the drying of colloidal suspensions, this work demonstrates the formation of nanoparticles in situ due to a change of solvent quality and subsequent deposition of particles at the pinned contact line. Using the theory of drying of binary solutions, we calculate the temporal variation of composition. The drying paths passing through the low-concentration branch of the binodal give rise to nanoparticles, whereas those passing through the high-concentration branch yield porous films. Spherical polymeric nanoparticles in the size range of 250-700 nm were synthesized using this technique starting from drops with different initial polymer concentration. The method is a cost-effective (no high-speed mixing is required) and scalable alternative to conventional flash nanoprecipitation for synthesizing polymeric nanoparticles for potential applications in drug delivery, diagnostics, and polymer recycling.

Influence of synthesis conditions and raw materials on the properties of N‐chlorosulfonamides immobilized on granular styrene–divinylbenzene polymer carriers

AbstractPolymer materials with immobilized functional groups–donors of active chlorine are widely used to create products with a microbiocidal effect and increased resistance to microbial contamination. In this work, various methods for the synthesis of granular styrene–divinylbenzene polymers with N‐chlorosulfonamide groups were investigated. It has been shown that the synthesis of polymers with chlorine‐active SO2NNaCl groups from a non‐functionalized styrene–divinylbenzene polymer matrix through the stage of its sulfochlorination with chlorosulfonic acid in dichloromethane for 6–7 h is optimal. These products contain approximately 11% of active chlorine and maintain a stable particle size distribution. When cation exchangers such as Purolite C100 are used as the initial polymer carrier, the content of chlorine‐active groups in the target product is approximately 9%, and an increase in the content of the dust fraction is observed. The obtained samples, regardless of the synthesis method, are capable of releasing active chlorine into solutions containing amino compounds. The microbial impurities in water also cause the emission of active chlorine in an amount that does not depend on the loading of the polymer, but is determined by the concentration of microbes, due to which a pronounced antimicrobial effect is observed. In this case, the resulting products do not cause further decomposition of the functional groups of the polymer, which indicates the high service life of the latter. The availability of raw materials, relative ease of synthesis, stability, possibility of regeneration and microbiocidal properties of the studied polymers make them promising for use as components of water and air purification systems and other products for medical and industrial purposes. © 2024 Society of Chemical Industry.

Interactions of proteins with heparan sulfate.

Heparan sulfate (HS) is a glycosaminoglycan, polysaccharides that are considered to have arisen in the last common unicellular ancestor of multicellular animals. In this light, the large interactome of HS and its myriad functions in relation to the regulation of cell communication are not surprising. The binding of proteins to HS determines their localisation and diffusion, essential for embryonic development and homeostasis. Following the biosynthesis of the initial heparosan polymer, the subsequent modifications comprise an established canonical pathway and a minor pathway. The more frequent former starts with N-deacetylation and N-sulfation of GlcNAc residues, the latter with C-5 epimerisation of a GlcA residue adjacent to a GlcNAc. The binding of proteins to HS is driven by ionic interactions. The multivalent effect arising from the many individual ionic bonds between a single protein and a polysaccharide chain results in a far stronger interaction than would be expected from an ion-exchange process. In many instances, upon binding, both parties undergo substantial conformational change, the resulting hydrogen and van der Waal bonds contributing significant free energy to the binding reaction. Nevertheless, ionic bonds dominate the protein-polysaccharide interaction kinetically. Together with the multivalent effect, this provides an explanation for the observed trapping of HS-binding proteins in extracellular matrix. Importantly, individual ionic bonds have been observed to be dynamic; breaking and reforming, while the protein remains bound to the polysaccharide. These considerations lead to a model for 1D diffusion of proteins in extracellular matrix on HS, involving mechanisms such as sliding, chain switching and rolling.

Influence of the solvent removal method on the morphology of polystyrene porous structures prepared via thermally induced phase separation

Thermally induced phase separation (TIPS) allows preparation of nano and micro-porous structured materials for various applications. The literature thoroughly examines the impact of initial polymer solution concentration and cooling rate on the products morphology. On the contrary, the influence of the solvent removal methods was so far researched scarcely. Hence, we compare both qualitatively and quantitatively the effects of the solvent removal method on pore size distribution, structure, porosity, and thermal conductivity. Our study was carried out with samples prepared by TIPS from polystyrene/cyclohexane solutions employing either extraction agent or lyophilization at different solvent removal temperatures. Materials exhibited interconnected pore structure, implying good sound insulation properties, and had low thermal conductivity, offering the combination of thermal and sound insulation in one layer of material. Pore sizes after lyophilization were up to two times larger than after solvent removal by an extraction agent. On the other hand, the use of extraction agent led up to 10% porosity decrease with average porosity after lyophilization being above 82%. Our findings demonstrate that the solvent removal method is an important parameter during TIPS and that pros and cons of both methods should be carefully considered to obtain optimal material and TIPS process economy.

Broad-Purpose Solutions of N-Chlorotaurine: A Convenient Synthetic Approach and Comparative Evaluation of Stability and Antimicrobial Activity

Solutions of N-chlorotaurine (NCT) are effective microbiocidal agents with a broad spectrum of pharmacological activity and outstanding tolerability. The main problem limiting their medical use is their instability, which is generally inherent in solutions of all chlorine-active compounds. In this work, we developed a new synthetic approach to the synthesis of such solutions, which consists in the activation of granular and fibrous polymeric materials with immobilized N-chlorosulfonamide groups, which act here as a chlorinating agent. It was shown that when such polymers are added to taurine solutions, NCT solutions with a chemical composition suitable for immediate medical use can be obtained. The stability of such solutions under various conditions was analyzed in comparison with NCTs obtained by the classical method from sodium hypochlorite. It was confirmed that the process of decomposition of all studied solutions obeys the kinetic laws of the first-order reaction. It was proven that solutions obtained from granular polymers are more stable both in terms of active chlorine concentration and in terms of pH, and their additional buffering is not needed. The stability of solutions decreases when they are stored in the presence of polymers used, with an increase in the excess of taurine and with acidification. The high sensitivity of all obtained solutions to UV radiation was also noted. The antimicrobial properties of NCT solutions obtained from polymers are not inferior to those obtained from sodium hypochlorite at the same concentration of active chlorine. Considering the stability and compactness of the initial chlorine-active polymers, as well as the possibility of their multiple regeneration, the developed method can form the basis of the technology for obtaining multifunctional NCT solutions for medical purposes with the desired physical and chemical properties without using special equipment or specific reagents.

The impact of post-radiation high-temperature shear grinding on the thermal and mechanical properties of polypropylene

The effect of input doses of 60Co γ-radiation from 80 to 12,000 kGy on the thermophysical properties and thermal stability of samples of polypropylene granules and powder obtained by high temperature shear grinding of irradiated granules, as well as on the tensile strength properties of a plate made from irradiated granules and their corresponding powders, was studied. The thermophysical properties of the powder are determined by the changes introduced by radiation into the initial polymer granules. The effects of radiation in air (environments with oxygen) were studied. Grinding redistributes oxygen-containing functional groups from the surface layer of irradiated granules throughout the entire volume of the obtained powder leading to the destruction of polymer chains as there is a component due to thermal destruction of radiolyzed polymer chains. High-temperature shear grinding of irradiated granules has a significant effect on the product powder, reducing its thermal stability but increasing the tensile strength of plates pressed from it at low absorbed doses. The current work shows that radiation treatment coupled with high temperature shear grinding could be a method for modifying the properties of polymers so that polypropylene waste can be processed for other applications.

Additive manufacturing and joining double processes of ceramic-resin green bodies using a single- or double-phase photocuring slurry

The present work focuses on a double process involving additive manufacturing and joining of ceramic-resin green bodies, aiming to overcome the challenges of printing long-span and large-size ceramic specimens. Through partitioned 3D printing, individual green bodies were built and then joined together using either a single-phase slurry (Al2O3) or a double-phase slurry (Al2O3 and ZrO2). The impact of sintered temperature, photocuring duration time, and sandwich layer thickness on the three-point bending strength of the joined specimens was investigated. The analysis of photocuring depth, thermogravimetry, and composition structure characteristics reveals two significant joining mechanisms, namely initial polymer network joining and ultimate grain bonding and growth joining, which play a crucial role in holding the connection shapes and enhancing the connection strength. Furthermore, the bending strength analysis indicates a positive correlation between sintering temperature and bending strength, while a negative correlation is observed between sandwich layer thickness and bending strength. The photocuring duration time has no significant impact on the bending strength. Finally, the double-phase slurry demonstrates superior connection performance, but the joining strength is decreased to 44.53 % of the sintered substrate specimens due to the presence of joining defects such as flow channel pores and lamellar gaps. These defects have prompted the development of lamellar structures, flow channel pores, and intercrystalline fracture regions, consequently reducing the overall strength.

Malignant ureteral obstruction: comparison of metallic, 8 French and 6 French ureteric stents after failure of initial ureteric stent.

Malignant ureteric obstruction is a significant management challenge. The failure of ureteric stents often leads to long-term nephrostomy tubes. This is delayed for as long as possible due to its' associated morbidity. Several types of ureteric stents are available, however there is little evidence demonstrating which stents are better for preventing progression to nephrostomy tubes. This study looked to determine whether a new 6 French (Fr) polymer stent, 8Fr polymer stent or metallic stent achieved a longer functional duration once the initial polymer ureteric stent failed. A retrospective, longitudinal study was performed at a single tertiary institution. All patients who underwent ureteric stenting with a 6Fr polymer stent for malignancy between 2010 and 2020 were included. Patients were followed up until death with ureteric stent in situ or permanent nephrostomy tube insertion. A total of 46 patients (66 ureters) had ureteric stents inserted for malignancy. From initial ureteric stent failure, 10 stents were changed to a new 6Fr polymer stent, 42 were changed to an 8Fr polymer stent and 14 were changed to a Resonance® 6Frmetallic stent. The Resonance 6Fr metallic stent had the longest median functional duration of 14months (p = 0.012). Resonance® 6Fr metallic stents appear to have a significantly longer functional duration than a new 6Fr polymer stent or 8Fr polymer stent, which may allow patients to enjoy a better quality of life and delay permanent nephrostomy tube insertion.

A novel process for recovery and exploitation of polyesters and polyamides from waste polymeric artifacts

Plastic waste is one of the world's biggest sources of pollution. Despite the growing trend towards recycling, there are currently no effective technologies to offset the continuous increase in plastic production. Polyesters and polyamides are among the most widely produced single-use plastics, mainly used in the manufacture of textiles and soft drink bottles. Currently, only a small proportion of these polymers can be effectively recycled. The two primary methods employed for this purpose are mechanical and chemical recycling. Presently, mechanical recycling remains the more widely adopted process within the industrial sector. However, the treatment process is limited to a narrow range of waste materials as it is impossible to remove dyes and the mechanical properties deteriorate due to incompatibility between different plastic materials. Another critical limit of this recycling technology is the limited number of recycling loops that can be done due to the thermal degradation that occurs during the extrusion process. The alternative option is chemical recycling, which allows the depolymerization of the original product to recover the monomers directly. The main drawbacks are the long reaction times and the many solvents needed to achieve high-purity products. As a results, chemical recycling is only economically feasible for large companies that can produce the virgin polymer in situ. In this work, a new technology has been patented. This process consists of three main steps. The first one is the distillation-assisted cyclodepolymerization (DA-CDP), introduced as a modification of the CDP process. In this unit, cyclic oligomers together with high molecular weight compounds are produced. Then, after polymer purification, it is possible to achieve the same molecular weight as the initial polymer in less than 30 min, exploiting the ring-opening polymerization (ROP) of the next step.

SO3-COF@Al2O3 modified cathode electrode materials enhance the cycling ability of lithium sulfur batteries.

Herein, a covalent organic framework (SO3-COF) containing sulfonic acid groups has been developed on the surface of alumina by a one-step method, labeled as SO3-COF@Al2O3. The experimental results show that SO3-COF@Al2O3 can effectively inhibit the shuttle effect of soluble lithium polysulfide (LiPSs) in LSBs after loading the active material sulfur, and exhibits better cycling behavior than the initial polymer SO3-COF. The initial discharge specific capacity of this electrode material at 0.05C is as high as 1141 mA h g-1, and the capacity can be maintained at 466 mA h g-1 after 500 cycles with a capacity decay rate of 0.08% per cycle.

Connecting Structural Characteristics and Material Properties in Phase-Separating Polymer Solutions: Phase-Field Modeling and Physics-Informed Neural Networks.

The formed morphology during phase separation is crucial for determining the properties of the resulting product, e.g., a functional membrane. However, an accurate morphology prediction is challenging due to the inherent complexity of molecular interactions. In this study, the phase separation of a two-dimensional model polymer solution is investigated. The spinodal decomposition during the formation of polymer-rich domains is described by the Cahn-Hilliard equation incorporating the Flory-Huggins free energy description between the polymer and solvent. We circumvent the heavy burden of precise morphology prediction through two aspects. First, we systematically analyze the degree of impact of the parameters (initial polymer volume fraction, polymer mobility, degree of polymerization, surface tension parameter, and Flory-Huggins interaction parameter) in a phase-separating system on morphological evolution characterized by geometrical fingerprints to determine the most influential factor. The sensitivity analysis provides an estimate for the error tolerance of each parameter in determining the transition time, the spinodal decomposition length, and the domain growth rate. Secondly, we devise a set of physics-informed neural networks (PINN) comprising two coupled feedforward neural networks to represent the phase-field equations and inversely discover the value of the embedded parameter for a given morphological evolution. Among the five parameters considered, the polymer-solvent affinity is key in determining the phase transition time and the growth law of the polymer-rich domains. We demonstrate that the unknown parameter can be accurately determined by renormalizing the PINN-predicted parameter by the change of characteristic domain size in time. Our results suggest that certain degrees of error are tolerable and do not significantly affect the morphology properties during the domain growth. Moreover, reliable inverse prediction of the unknown parameter can be pursued by merely two separate snapshots during morphological evolution. The latter largely reduces the computational load in the standard data-driven predictive methods, and the approach may prove beneficial to the inverse design for specific needs.

In Vitro and In Vivo Hydrolytic Degradation Behaviors of a Drug-Delivery System Based on the Blend of PEG and PLA Copolymers.

This paper presents the in vitro and in vivo degradation of BEPO, a marketed in situ forming depot technology used for the formulation of long-acting injectables. BEPO is composed of a solution of a blend of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) triblock and diblock in an organic solvent, where a therapeutic agent may be dissolved or suspended. Upon contact with an aqueous environment, the solvent diffuses and the polymers precipitate, entrapping the drug and forming a reservoir. Two representative BEPO compositions were subjected to a 3-month degradation study in vitro by immersion in phosphate-buffered saline at 37 °C and in vivo after subcutaneous injection in minipig. The material erosion rate, as a surrogate of the bioresorption, determined via the depot weight loss, changed substantially, depending on the composition and content of polymers within the test item. The swelling properties and internal morphology of depots were shown to be highly dependent on the solvent exchange rate during the precipitation step. Thermal analyses displayed an increase of the depot glass transition temperature over the degradation process, with no crystallinity observed at any stage. The chemical composition of degraded depots was determined by 1H NMR and gel permeation chromatography and demonstrated an enrichment in homopolymers, i.e., free PLA and (m)PEG, to the detriment of (m)PEG-PLA copolymers in both formulations. It was observed that the relative ratio of the degradants within the depot is driven by the initial polymer composition. Interestingly, in vitro and in vivo results showed very good qualitative consistency. Taken together, the outcomes from this study demonstrate that the different hydrolytic degradation behaviors of the BEPO compositions can be tuned by adjusting the polymer composition of the formulation.

Synthesis of molecularly imprinted polymer by precipitation polymerization for the removal of ametryn

Ametryn (AME) is a triazine herbicide which is mainly used to kill unwanted herbs in crops. Despite its importance in agriculture, the usage of AME also poses a risk to humans and the ecosystem due to its toxicity. Hence, it is important to develop a method for the effective removal of AME from various water sources which is in the form of molecular imprinting polymer (MIP). In this study, MIP of AME was synthesized via precipitation polymerization using AME as the template molecule with three different functional monomers including methacrylic acid (MAA), acrylamide (AAm) and 2-vinylpyridine (2VP). The three different synthesized polymers namely MIP (MAA), MIP (AAm) and MIP (2VP) were characterized using Fourier Infra-red spectroscopy (FTIR) and Field Emission Electron Microscopy (FESEM). Then, the batch binding study was carried out using all three MIPs in which MIP (MAA) attained the highest rebinding efficiency (93.73%) among the synthesized polymers. The Energy-Dispersive X-ray spectroscopy (EDX) analysis, Brunauer–Emmett–Teller (BET) analysis and thermogravimetric analysis (TGA) were also conducted on the selected MIP (MAA). Adsorption studies including initial concentration, pH and polymer dosage were also conducted on MIP (MAA). In this study, the highest adsorption efficiency was attained at the optimum condition of 6 ppm of AME solution at pH 7 with 0.1 g of MIP (MAA). MIP (MAA) was successfully applied to remove AME from spiked distilled water, tap water and river water samples with removal efficiencies of 95.01%, 90.24% and 88.37%, respectively.Graphical

Low-temperature micromechanical properties of polyolephin/graphene oxide nanocomposites with low weight percent filler

The effect of small impurities of reduced graphene oxide (rGO) on microhardness of polyethylene (PЕ) and polypropylene (PP) matrices and the reaction of these nanocomposites and initial polymers on the influence of localized load in the temperature range of 77–295 K were studied. When rGO was introduced, PE practically did not change its properties, whereas the introduction of 0.3 wt% rGO into the PP matrix was accompanied by a significant increase in microhardness, especially in the room temperature range (by approximately 70%). A transition to reversible deformation was detected when the indenter impressions applied in liquid and gaseous nitrogen at temperatures below the threshold (T < 174.5 K for PP and T < 226.5 K for nanocomposite PP + 0.3 wt% rGO) were not fixed on the surface of the samples after their heating in the measuring device to room temperature.