Collagen–pectin–methyl methacrylate copolymers were synthesized in an acetic acid dispersion in the presence of a triethylboron amine complex. The synthesis temperature was found to have little effect on the copolymer composition, while its morphology changed significantly. By using the amine complex in combination with p-quinone during the synthesis of collagen–pectin–methyl methacrylate copolymers, it was possible to vary the copolymer composition, the molecular weight of grafted polymethyl methacrylate, and the resulting morphology depending on the structure of the p-quinone used. Hydrogels based on the synthesized copolymers were formed in the presence of glutaric aldehyde. Their moisture-absorbing properties and stability in buffer solutions make them promising base materials for regenerative medicine. The absence of cytotoxicity and the stimulatory effect of the obtained materials on the growth of human dermal fibroblasts were demonstrated by the MTT assay. The analysis of biocidal activity indicates that collagen–pectin–methyl methacrylate hydrogels have a clear potential as fungusresistant bactericidal materials.

The geometry and structure of hollow fiber membranes fabricated from polysulfone by the dry-wet phase inversion method were studied with the help of scanning electron microscopy. Various amine hardeners and difunctional polyetheramines were analyzed as potential components of sealing compounds. The fabricated hollow fiber membranes were sealed in model membrane modules using epoxy sealing compounds with different hardeners. The applicability of these materials was assessed based on the presence of defects when gases were supplied under pressure at the contact point between the membrane and the epoxy. The use of polyetheramine as an amine hardener for the epoxy systems caused no defects at the point of contact between the hollow fiber membranes and the epoxy compound, even when pressures up to 0.5 atm were applied. This ensures high selectivity values for the He/N₂ gas pair in the resulting membrane modules.

The benefits and advantages of using 3D gradient printing to create ABS plastic-based layered composites reinforced with carbon fibers (CF) and iron oxide nanoparticles (NP) were studied. Samples with different additive contents, as well as a gradient sample with a gradual change in composition (additive content, wt.%: 30 CF, 15 CF, 0, 5 NP, 15 NP), were 3D printed. The thermophysical, mechanical, and magnetic properties of all samples were determined, and the influence of both qualitative and quantitative composition on them was analyzed. Based on the 3D modeling and the preliminary analysis of interlayer adhesion, the need for an intermediate layer of pure polymer between the layers with CF and NPs was shown. Optimal 3D printing settings were selected, and a part with a gradient composition was manufactured and subsequently used to assemble an industrial robot. Overall, the results reveal that deliberate incorporation of various materials or additives into specific regions of a composite offers a way to realize unique combinations of its mechanical, thermal, and electrical properties, tailored to specific applications.

This article examines the effect of few-layer graphene (FLG) at different compositions on the strength, wear resistance, and thermal conductivity of epoxy resin. The FLG composition was varied using ammonium nitrate and potassium nitrate as synthesis precursors. The incorporation of FLG enhanced the compressive strength and wear resistance of epoxy resin. Increasing the number of heteroatoms in the FLG structure had little influence on the compressive strength of epoxy resin but improved its wear resistance.

A new two-stage method for the fabrication of a porous membrane from polyphenylene sulfide (PPS) was proposed. The approach involves the production of PPS films with a filler and the subsequent removal of the filler material from the film to form a porous structure. Polyarylene sulfones, such as polysulfone (PSF), polyethersulfone, and polyphenylene sulfone (PPSU), were investigated as fillers for the first time. The concentration of the pore-forming additive was 30 % (wt.). The filler was extracted from the films through thermolysis in N-methyl-2-pyrrolidone (NMP) for 12 h at different temperatures (70, 90, and 202 °C). Thermolysis conditions for the complete removal of PSF and PPSU from the PPS film were found empirically. The porous structure of the resulting PPS membranes was examined using scanning electron microscopy, liquid porometry, and gas permeability testing for specific gases (He, N₂, and CO₂). The samples of porous membranes from PPS with an average pore diameter of 160 nm, corresponding to the range of microfiltration, were o btained.

The effect of treatment of polyphenylene sulfone (PPSU) and polysulfone (PSU) hollow fiber membranes with superheated water steam under autoclaving conditions for 270 h was investigated for the first time. The resistance of these membranes to repeated steam sterilization, a key parameter for their application in the purification of media that may contain pathogenic organisms, was evaluated. PPSU membranes were found to exhibit high thermal stability and resistance to hydrolysis and retain their functional characteristics after multiple sterilization cycles. The obtained data underscore the potential of PPSU as a promising material for creating durable and reliable hollow fiber membranes to carry out processes that necessitate the use of repeated sterilization. 

Polyethylene terephthalate (PET) film has good dielectric properties but high radiation-induced conductivity, which can be reduced by doping commercially available electrical insulation films with small electron-trapping molecules. This study investigates the doping process of PET-CE capacitor film (State Standard 24234-80) using fluorenone-based dopants, such as 2,7-dinitro-9-fluorenone (DNF) and 2,5,7-trinitro-9-fluorenone (TNF), and focusing on the role of the solvent (ethylene glycol and benzyl alcohol). The optimal doping temperature range was selected to be between the glass transition temperature of the doping polymer (88 °С for PET, lower limit) and the boiling point of the solvent (upper limit). The appropriate solvent and dopant solution concentrations were determined. Based on the experimental results, ethylene glycol and benzyl alcohol were selected as solvents for TNF and DNF, respectively. The following solvent selection criteria for doping systems were established: high boiling point, high dopant solubility, and low affinity for the polymer matrix. 

The effect of adding 1,4-dioxane to casting solutions based on poly(acrylonitrile-co-methyl acrylate) (poly(AN-co-MA)) using solvents such as dimethyl sulfoxide (DMSO) and N-methylpyrrolidone (NMP) was investigated. The introduction of the soft precipitant altered the rheological properties of the studied solutions: it reduced viscosity in the poly(AN-co-MA)/NMP system and caused an opposite change in the poly(AN-co-MA)/DMSO system. A direct correlation was established between the solution viscosity and the deposition rate during membrane formation via phase inversion. The incorporation of 1,4-dioxane enabled controlled modification of the membrane morphology and filtration performance by reducing the average pore size. The reduction in the average pore size was more pronounced in the membranes with NMP than in the membranes with DMSO (up to 11.8 nm and 19.1 nm, respectively). During the filtration of crude oil and 100 g/L oil solution in toluene, the rejection of asphaltenes by the membranes of both types was over 98 %. These findings confirm the potential of 1,4-dioxane in the development of membranes with tailored properties for application in the petrochemical industry. 

The temperature dependences of the diffusion, solubility, and permeability coefficients for ladder-like polyphenylsilsesquioxane (L-PPSQ) samples with molecular weights of 400, 600, and 1000 kDa were analyzed. A comparison, in terms of the gas transport parameters and temperature coefficients, with other silicon-containing polymers revealed that L-PPSQ is most similar to glassy polyvinyltrimethylsilane (PVTMS) rather than to polydimethylsiloxane (PDMS), which is structurally related to it. The heat of sorption values obtained for the studied samples using the temperature dependences are consistent with those from the literature for polytrimethylsilylpropyne (PTMSP), while their diffusion activation energies are more in agreement with PDMS and PVTMS, which may indicate the presence of enclosed free volume elements in L-PPSQ, comparable in size to the ones in PTMSP. The observed tendency of the permeability coefficient to increase with temperature confirms the dominant contribution of the diffusion component of permeability in L-PPSQ. The molecular weight of L-PPSQ was found to have no influence on its gas transport properties in the range of 400–1000 kDa. Therefore, the production of asymmetric and composite membranes is limited solely by the mechanical properties and solubility of L-PPSQ with different molecular weights. 

The introduction of hybrid nanocomposites with graphene particles in which surfaces are modified by nano-dispersed SiO₂ significantly improves the thermal stability of siloxane materials. By carbonizing rice husk using a tailored method of self-propagating high-temperature synthesis, a hybrid nanocomposite, low-layer graphene/SiO₂, was obtained. Upon the incorporation of carbonized starch and carbonized rice husk into rubber mixtures based on polydimethylsiloxane, the vulcanization proceeded at an increased rate with a longer induction period. The resulting experimental mixtures were used to produce rubber samples subjected to physical and mechanical testing before and after thermal aging for 72 h at 250 °C in order to determine their elastic and strength characteristics. Overall, the outcomes of these tests confirm the effectiveness of the synthesized additives as thermal stabilizers for siloxane rubbers. 

The process of benzoxazine resin curing in the presence of various catalysts was investigated. The catalytic activities were compared to identify the catalyst that most effectively reduced the benzoxazine curing temperature. The effect of the catalyst content on the curing of benzoxazine was assessed. The activation energies for the curing process were determined. The curing kinetics parameters were calculated from differential scanning calorimetry (DSC) data using Thermokinetics3 software. The possibility to control the temperature front and conversion of the binder through layer-by-layer changing of its composition (by varying the content of the catalyst in the benzoxazine system) across the thickness of the product, and thus altering the binder reactivity, was demonstrated. Based on the results obtained, a single-stage curing mode of benzoxazine binder that shortens the curing cycle through composite molding under dynamic heating conditions was singled out.

This article introduces an innovative method for quantifying the degree of composition homogeneity in copolymers using mathematical modeling techniques. Applicable to copolymers for which the mechanism of microstructure formation can described in terms of the Markov chains, the method consists in obtaining a set of shares of unit sequences of a given length from a high-resolution NMR spectrum (set A) and then finding, through mathematical modeling of the Markov matrix, transient probabilities in order to build a model of a polymer chain containing such a set of shares of unit sequences (set B) that matches, as close as possible, set A. The dispersion resulting from the comparison of sets A and B is proposed as a quantitative criterion for the degree of composition homogeneity.