Polymer Science, Series B最新文献

We have successfully developed a superhydrophobic and superoleophilic cellulose paper by in situ formation of polyhedral oligomeric silsesquioxane (POSS) blocks on its surface. These POSS blocks endow the cellulose paper with an optimal micro-nano structure and hydrophobic composition, resulting in superhydrophobicity and enhanced abrasion resistance. The modified cellulose paper was characterized using scanning electron microscopy, energy dispersion spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analysis to confirm the structures. The oil-water separation performance of the as-prepared paper was validated through preferential adsorption and gravity-driven separation processes, demonstrating high separation efficiency and throughput for various oil/water mixtures. This innovative approach provides a promising solution for large-scale oil spill accidents while offering excellent reusability and stability.

The present paper describes the formation of microplastics from foamed polystyrene as a result of exposure to insects, namely the larvae of the beetle Zophobas morio in real-life conditions. Larvae were cultured with foamed polystyrene in the absence of food and in control groups with normal nutrition. Most larvae survived and successfully developed into pupae. The effect of larvae on polystyrene is manifested by its mechanical destruction when larvae build tunnels in the volume of polystyrene material, resulting in the formation of a finely dispersed fraction of polystyrene (i.e., microplastics). FTIR, Raman, and NMR spectrometry methods revealed no significant differences in the original polystyrene and polystyrene crushed by larvae; also, according to the GPC data, no significant change in the molecular weight of polystyrene was detected as a result of contact with Z. morio larvae and passage through their gastrointestinal tract. The data obtained confirm that the main result of larvae impact on polystyrene foam is its crushing with formation of microplastic without chemical modification and change of molecular weight.

The effect of ultraviolet radiation on the physico-mechanical properties of fibrous composite materials modified with polysulfone has been studied. In most cases, ultraviolet radiation has virtually no effect on the properties of epoxy fiberglass. Nevertheless, the specific fracture toughness of the winding composite modified by 20 wt % of polysulfone has increased (by 45% or up to 1.9 kJ/m² after 5 days of irradiation). In other cases, the change in the properties (compressive and shear strength) of the composites has not exceeded 10%. In addition, in all the conducted experiments concerning the physico-mechanical properties, the addition of polysulfone has led to an increase in the characteristics of fiberglass (crack resistance, shear and compression strength).

Mathematical modeling of the kinetics of peroxide vulcanization of rubbers based on butadiene–nitrile rubbers and their deformation–strength properties has been carried out. The modeling results are compared with the experimental data obtained for carbon black-filled compositions based on NBRS-40AMN rubber, including the vulcanizing agent 1,4-di(tert-butylperoxyisopropyl)benzene in different dosages. The mathematical model of the vulcanization kinetics of the compositions relies on the analysis of the formal kinetic scheme of radical reactions occurring during peroxide vulcanization in the presence of air oxygen. Using this model the influence of oxygen on the ratio of carbon–carbon and ether–ether crosslinks in the formed vulcanization network is analyzed. To describe the deformation curves of peroxide vulcanizates with different content of the vulcanizing agent, a model based on the series decomposition of the network strain energy by invariants of the left Cauchy–Green strain tensor and including the linear viscoelasticity equation is proposed. The vulcanizate breakdown process is characterized by a kinetic equation in which a network deformation model is used which allows an adequate description of the deformation curves of crosslinked elastomers up to failure. By analyzing the dependences of the model parameters on the content of the vulcanizing agent, conclusions are made about changes in the structure of the vulcanization network with increasing degree of crosslinking.

The degradation of stone cultural relics due to environmental factors, such as freeze-thaw, acid rain, and UV radiation, has necessitated the development of advanced protective coatings. In this study, fluorinated poly(methyl methacrylate-butyl acrylate) modified by vinyl triethoxysilane coating was synthesized via a one-pot method to enhance the durability and protective performance of coatings. The structure, thermal stability, and microstructure of the synthesized polymer were characterized using FTIR, XRD, TG, and SEM. The aging resistance of the coating formed was systematically evaluated under simulated freeze-thaw, acid, and UV aging conditions. Key properties, including hydrophobicity, chromaticity difference (ΔE), transparency, and mass loss rate, were analyzed before and after aging. Among the aging factors, UV exposure exhibited the most pronounced impact on these properties. However, polymer coatings with 18.5 mmol vinyl triethoxysilane demonstrated superior resistance to UV-induced degradation, maintaining a contact angle of 104.55°, the stability change of ΔE is 0.73, and acceptable transparency and mass loss rates after aging.

Acrylate emulsions were prepared through atom transfer radical polymerization (ARGET-ATRP) with methyl methacrylate (MMA), ethyl acrylate (EA) and butyl acrylate (BA) as monomers using electron transfer-activated regenerative catalysts, with benzyl bromide (BBB) and ethyl 2-bromoisobutyrate (EBIB) as a complex initiation system and copper bromide and bipyridine as a catalytic system. The effects of the temperature, the compound initiator ratio, the compound emulsifier ratio, the ligand type and the content on the polymerization dynamics were examined, and the polymer was characterized by infrared spectroscopy and 1H NMR. This study revealed that the monomer conversion rate and the apparent polymerization rate are positively correlated with the reaction temperature, and the apparent activation energy of the reaction was E_a = 57.63 KJ/mol. When benzyl bromide was used as the initiator alone, the initiation efficiency of the system was low. After EBIB was added, the initiation effect was greater for benzyl bromide : EBIB = 7 : 3, and the conversion rate and polymerization rate were positively correlated with the amount of reducing agent. The monomer conversion rate and apparent growth rate constant were the greatest when the mass ratio of the emulsifier sodium dodecyl sulfate and sodium dodecyl benzene sulfonate was 7 : 3. Different ligands affected the monomer conversion rate and apparent growth rate constant, and with increasing ligand content, the monomer conversion rate and apparent polymerization rate constant increased. According to the results of infrared spectroscopy and nuclear magnetic hydrogen spectroscopy, the compound initiator successfully triggered the polymerized monomer to generate the ternary copolymer.

Nonlinear amphiphilic thermoresponsive copolymers of N-isopropylacrylamide with triethylene glycol dimethacrylate containing amino or carboxyl end groups were synthesized by radical copolymerization in ethanol in the presence of cysteamine or 3-mercaptopropionic acid. Their molecular weights, polydispersity, and glass transition temperatures were determined. The behavior study of the copolymers in water showed that the cloud point depends on the concentration of the copolymers in solution, their composition, and nature of functional groups. The copolymers of N-isopropylacrylamide demonstrate low cytotoxicity against Vero and HeLa cells, which allows their use in biomedical applications.

A series of oligoisocyanurates of isophorone diisocyanate with different conversion of isocyanate groups have been synthesized in the presence of a 1,4-diazabicyclo[2.2.2]octane/propylene oxide catalytic system. The obtained samples have been characterized by IR and ¹³C NMR spectroscopy. It has been shown that the ratio of aliphatic and cycloaliphatic isocyanate groups in the oligoisocyanurates is close to that in the monomer. Investigation of kinetics of the urethane formation involving isophorone diisocyanate and its oligoisocyanurates with 2-hydroxyethyl methacrylate in the acetone medium has revealed that the presence of traces of the catalytic system in oligoisocyanurates significantly contributes to the urea formation reaction. In this regard, the synthesis of water-dispersive polyurethane acrylates based on isophorone diisocyanate oligoisocyanurates has been carried out in the medium of a hydrophobic solvent, methylene chloride. According to the analysis of the hydrodynamic parameters of the obtained aqueous dispersions, the size of the particles of the dispersed phase increases with an increase in the conversion of isocyanate groups in the oligoisocyanurates of isophorone diisocyanate. The observed regularities are apparently due to an increase in the content of the high-molecular fraction in the corresponding oligoisocyanurates.

To address the issue of poly(ethylene terephthalate) being highly hydrophobic and prone to static electricity due to friction, this study modifies PET through copolymerization with flexible long-chain monomers containing hydrophilic functional groups, creating a novel spinning-grade modified polyester with both hydrophilic and antistatic properties. Specifically, polyethylene glycol with a specific molecular weight (M_n = 4000) was used as a reactive hydrophilic and antistatic modification component, with a copolymerization content of 5~20%. Testing and characterization of the copolyester structure and properties showed that, compared to pure PET polyester, the introduction of hydrophilic ether bonds resulted in a significant hydrophilic modification effect, with the moisture absorption rate increasing from 0.11 to 1.12% and the surface water contact angle decreasing from 89.6° to 64.1°. Meanwhile, the volume resistivity of the copolyester decreased by 3–4 orders of magnitude compared to pure PET. This study improves the hydrophilic and antistatic properties of PET polyester through a low-cost modification method, providing essential reference for the development of functional polyesters and their fiber products.