Abstract Enhancing on the crystallization ability of poly(L-lactic acid) (PLLA) during practical processing is one of the most effective way to overcome the poor heat resistance. In this work, N,N '-adipic bis(piperonylic acid)dihydrazide (PAAH) was synthesized to be firstly used as a heterogeneous nucleating agent to evaluate its influence on the performances, including the crystallization, melting

Abstract Nanomodified polyetherimide samples obtained by fused deposition modeling using an experimental setup for three-dimensional printing of highly heat-resistant plastics are studied. Their structure and thermal properties are investigated by pycnometry, scanning electron microscopy, differential scanning calorimetry, thermogravimetry, and dilatometry. It is found that the modification of polyetherimide

Abstract Using X-ray diffraction, electron microscopy, and differential scanning calorimetry, the structure and mechanical properties of tubes based on poly (L-lactide) microfibers obtained by electrospinning from a dichloroethane solution and designed for implantation in small diameter blood vessels during prosthetics are studied. It is shown that freshly formed microfibers have an amorphous structure

Abstract Composites of various composition are obtained by the solid-phase mixing of thermoplastic polyesters poly(3-hydroxybutyrate) and polylactide under conditions of shear deformation in the presence of poly(ethylene glycol) as a plasticizer. The thermophysical parameters in primary and secondary heating scans are measured. It is shown that the original polyesters are immiscible polymers. The degree

Abstract The effect of residual secondary structures in peptides and proteins on their separation is considered within the framework of the lattice model of adsorption and chromatography of macromolecules. It is shown that, if the model takes into account secondary structures, such as helices, folds, or crosslinks, the retention volume may change considerably. At the same time, for short peptides with

Abstract The tilted lamellar phase of a symmetric rod–coil diblock copolymer is studied by dissipative particle dynamics simulation over a wide range of degrees of block segregation. The microphase separation in the copolymer and the orientational ordering of rigid blocks in the tilted phase are investigated. For the first time, spatial profiles of the orientational order parameter and the density

Abstract Films obtained from aqueous solutions of chitosan succinamide sodium salt are studied. It is found that the process of water vapor sorption by polymer films proceeds in an anomalous mode and the diffusion coefficients of water and the dioxidine drug in the films depend on the thickness of the samples and the concentration of the polymer in the initial solution. It is assumed that the dependence

Abstract The thermodynamic characteristics of deformation of thermoplastic elastomers obtained by the dynamic vulcanization of two crystallizable components polypropylene and ethylene-propylene-diene copolymer are studied by deformation calorimetry. The entropy and energy effects of deformation are determined for the original, oriented, and annealed (at 70°C) samples containing 20 and 29 wt % polypropylene

Abstract Poly(ethylene terephthalate)/clay nanocomposite multifilament yarn was manufactured by conventional masterbatch approach. Poly(butylene terephthalate) was used as a carrier polymer in masterbatch steps. The masterbatches were diluted into pilot melt spinning machine and subsequently drawn with 2.65 ratios to prepare fully oriented yarn. The degree of dispersion in nanocomposite fibers was

Abstract Phase equilibria in systems polystyrene–block and gradient n-butyl acrylate–styrene copolymers are studied for the first time using optical interferometry for polystyrene of various molecular weight and copolymers of different architecture. Phase diagrams, which are characterized by the upper critical solution temperatures, are constructed. The pair interaction parameters for these systems

Abstract This study focused on the preparation method and evaluation of micro-nano composites based on emulsion polymerization styrene butadiene rubber (ESBR) and kaolinite. A novel method – latex blending was utilized to improve the dispersion of kaolinite in matrix and obtain a semi-exfoliation type clay/polymer composite. The results showed that the kaolinite particles presented a semi-exfoliation

Abstract Magnetoactive elastomers based on polydimethylsiloxane functional oligomers with a concentration of magnetic iron microparticles of 70, 75, and 80 wt % are synthesized. Soft samples with low (about 2 kPa) elastic moduli are obtained by introducing side chains into the polymer network without using a low molecular weight oil. It is shown that the rigidity of the matrix can be controlled by

Abstract The adsorption of poly(acrylic acid) (PAA5K) with negative charge on the highly negatively charged polystyrene sulfate latex (PSL) particles at various ionic strengths were investigated in the present study. The adsorption of PAA was promoted with high ionic strength while the driving forces were mainly controlled by the non-electrostatic interactions including hydrogen bondings, dipole–ions

Abstract The rheological properties of aqueous suspensions of spherical and needle-shaped nanocellulose particles in the range of 25–70°C are compared. Nanocellulose samples are obtained by the acid hydrolysis of cotton cellulose fibers in H2SO4 (61–65%) at 25–45°C. The shape of nanocellulose particles affects the yield strength and non-Newtonian character of the suspension flow. In the shear stress

Abstract— Aqueous solutions of an acrylic copolymer and a low-molecular-weight anionic surfactant are studied using mesoscopic simulation by dissipative particle dynamics. The possibility of formation of a homogeneous film from the acrylic copolymer, where a domain structure is absent and a surfactant is separated from the polymer phase, is studied. A mesoscopic model taking into account the main structural

Abstract— The electron transport is studied experimentally by measuring pulsed radiation-induced conductivity in polyetheleneterephthalate under bulk irradiation of polymer films by fast electron pulses in a small-signal regime. Numerical simulation is performed using a multiple trapping model with an exponential energy trap distribution. It is shown that, contrary to the reported interpretation of

Abstract Microfiltration membranes have been obtained from polymethylpentene by phase separation of its dioctyl sebacate solutions under cooling. The dissolution of the polymer was carried out at its melting point followed by formation of membrane precursors in the form of films from the resulting solution, which were then cooled and washed with acetone to remove the ester and pore formation. Using

Abstract The effect of chitin nanofibrils on the sorption properties of composite films is studied. The value of sorption decreases with an increase in the content of chitin nanofibrils. It is assumed that the introduction of chitin nanofibrils into the chitosan matrix contributes to a denser packing of macromolecules, formation of a more ordered crystalline structure of the composite, and development

Abstract Dilute solutions of nitrile-butadiene rubbers in toluene, methyl acetate, ethyl acetate, and butyl acetate are studied by viscometry. The rubbers are obtained using paraffinate emulsifiers and contain the same amounts of acrylonitrile and different molecular weights. The effect of rubber molecular weight and solvent nature on the intrinsic viscosity [η], viscometric Huggins k' and Kraemer

Abstract The influence of cold rolling on the mechanical characteristics of polypropylene saturated with particles consisting of three to five monolayers of graphene (the degree of filling of 0.2–3.5 wt %) is studied. The nanocomposites are obtained by in situ filling, i.e., synthesis of the polypropylene matrix on the particles, thus allowing more uniform distribution of the filler throughout the

Abstract Using a twin-screw microextruder, fibers are synthesized from polylactide with the addition of two types of chitin nanofibrils—both original and modified with poly(ethylene glycol). The fibers are subjected to the additional high-temperature orientational drawing by a factor of 4 and 6. Composite materials are investigated by a complex of thermophysical and structural methods, and their physicomechanical

Abstract The design of biologically active dosage forms based on chitosan is significantly limited by its insolubility at pH values above 6.0–6.5 and worsening of its gastrointestinal absorption capacity upon transition to neutral and alkaline environmental conditions. The partial acylation of short-chain chitosans with the use of betaine in the presence of a coupling reagent (betaination) allows one

Abstract Using the pulsed molecular acoustics method, the velocity of longitudinal and lateral sound waves in amorphous organic polymers is measured. The elastic moduli and Poisson ratio, as well as the previously introduced effective elastic modulus, are determined. It is shown that for amorphous polymers the ratio of the bulk modulus to the effective elastic modulus is a single-valued function of

Abstract The use of a solvent, Vaseline oil, for the orientational drawing of high-strength and high-modulus UHMWPE fibers is considered. Since the side effect of the residual solvent during orientational drawing of UHMWPE fibers is the formation of pores that reduce the packing density of macromolecules, then at a certain stage of drawing the fiber, the solvent is removed from it by washing in n-heptane

Abstract It is shown that a chitosan coating can be deposited on the pore surface of Celgard polyolefin matrices from aqueous solutions of chitosan saturated with carbon dioxide under high pressure; i.e., when carbonic acid is formed. To ensure the stability of the coating, the initially hydrophobic matrices should be pretreated in the presence of peroxycarbonic acid, which is formed when the aqueous

Abstract The structure of n-butyl acrylate–styrene block and gradient copolymers of various compositions is studied in detail, and their glass transition temperatures are determined. Influence of the architecture of copolymer macromolecules on the glass transition temperature is considered. Histograms of the size distribution of phases are constructed, and the density distribution of domains over the

Abstract It is shown that, in the melts of linear macromolecules, the effects of dynamic heterogeneity associated with the presence of end segments are not vanishingly small in the limit \(N \to \infty \), where \(N\) is the number of Kuhn segments in the macromolecule. The effect has a frequency nature, i.e., the division of the segments into “end” ones, more mobile in comparison with the “median”

Abstract A relaxation model for the structure ripening under annealing of a microphase-separated polymer film has been developed. Equations have been derived that describe the appearance and annihilation of defects in the kinetically controlled mode based on the experimental data on the hexagonal structure evolution. Using that equations, the time dependences of the defect-free area size have been

Abstract The appearance of an additional term in the glass transition criterion is substantiated. The concept is developed that glass transition occurs when the energy of thermal vibrations of the lattice per atom becomes less than the enthalpy of atomic delocalization—its ultimate displacement from the local equilibrium position. A linear relationship is ascertained between the energy of atomic delocalization

Abstract The molecular mobility of poly(4,4'-bis(4-aminophenoxy)biphenyl)imido-1,3-bis(3,3'-4,4'-dicarboxyphenoxy)benzene) films is studied by the thermally stimulated depolarization current (TSDC) technique and dielectric spectroscopy. The existence of two dipolar polarization relaxation regions (β and α) related to the local mobility in the glassy state and the cooperative segmental mobility in the

Abstract The X-ray diffraction patterns of polymers containing an active filler show reflections indicating formation of two to three kinds of nanostructures in them. Nanostructures 2–10 nm in size with the smallest average interplanar distances (2.1–4.0 Å) and, accordingly, with a strength higher than that of nanostructures in the polymer matrix of a blend are formed immediately around filler particles

Abstract The molecular mobility of poly(phenylene oxide) nanocomposites with endometallofullerene at a concentration of 0.1, 0.5, and 1.0 wt % is studied by dielectric spectroscopy. Two processes of dipole polarization relaxation in the glassy state (β-process) and in the rubbery state (α-process) are found. It is shown that the molecular mobility of the β-process related to the presence of a nanoadditive

Abstract The influence of synthetic water-soluble uncharged block copolymers on the multiplication of cells in a culture is studied. Their hydrophilic blocks are represented by linear poly(ethylene glycol) or branched polyglycerol, and hydrophobic blocks, by poly(propylene oxide) or polydimethylsiloxane. MCF-7/Adr cells are incubated with the copolymers in a serum-free culture medium for one hour,

Abstract The views of A.B. Zezin and V.A. Kabanov on the structure of polyelectrolyte complexes of linear polymers are considered and confirmed by studying chitosan hydrogels with lambda-carrageenan formed by regulated gelation. The complexes are visualized by transmission electron microscopy using osmium tetroxide for staining.

Abstract The effect of temperature on water sorption by gels based on the copolymers of N-isopropylacrylamide with sodium p-styrene sulfonate containing 1, 3, and 5 mol % of charged monomer units is studied in aqueous media in the presence of salt (NaCl, KCl) or urea. It is shown that the incubation of gels in salt solutions leads to compression of the gels. With increasing temperature, the collapse

Abstract The effect of a magnetic field on the phase transitions and structure of solutions of polyelectrolytes (gelatin, poly(acrylic acid), and poly(methacrylic acid)) at different pH values of the medium is studied. It is shown for the first time for polyelectrolyte–solvent systems that the magnetic field leads to an increase in the temperature of phase transitions and causes additional association

Abstract In the present paper, a CuI nanoparticle was grown in a polyvinyl alcohol (PVA) solution using tetramethylethylenediamine (TMEDA) as a crystal growth inhibitor. The effect of TMEDA on the structural, optical and electrochemical properties of CuI/PVA was investigated using X-ray diffraction (XRD), a scanning and transmission electron microscopy, UV–Vis spectroscopy, and cyclic voltammetry techniques

Abstract Silver nanoparticles are deposited on aramid fiber surfaces by a three-step process. Calcium chloride/ethanol coarsening of the aramid fiber is followed by surface functionalization with poly(dopamine) and electroless silver plating. The chemical structure and elemental composition of the aramid fibers are determined by X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy

Abstract Chitosan/poly(acrylamide-co-acrylic acid) double network hydrogels based on non-covalent bond and winding between molecular chains were synthesized by copolymerization reaction in the presence of Fe3+. The formation mechanism of chitosan/poly(acrylamide-co-acrylic acid) double network hydrogels was analyzed using UV–Vis spectra and FTIR, revealing that Fe3+ could form the electrostatic interaction

Abstract The polyacrylate-g-polysiloxane copolymers were prepared by condensation reaction of polyacrylate with polysiloxane. Nine different formulations of marine antifouling coatings based on TiO2 and polyacrylate-g-polysiloxane were fabricated. The coatings had strong adhesion to substrate due to the incorporation of main-chain acrylic moieties. The side-chain Si–O bonds from polysiloxane enable

Abstract Chitosan-graft-polyacrylic acid/graphite oxide (CTS-g-PAA/GO) superabsorbent composite was prepared by solution intercalation graft copolymerization of chitosan (CTS), acrylic acid and graphite oxide (GO). The composite was characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscope, thermogravimetric analysis

Abstract Hybrid hydrogels based on poly(N-isopropylacrylamide) and poly(acrylamide) containing CdTe quantum dots with UV sensitive response and including NaYF4:Yb/Er nanoparticles have been prepared through glow discharge electrolysis plasma. The fluorescence characteristic and temperature sensitivity of the prepared hydrogels have been most extensively studied. In addition, scanning electron microscopy

Abstract Naturally antibacterial-based materials are of interest for biomedical application specifically in wound dressing. The use of bioactive substance such as curcumin in combination with naturally abundant biopolymer bacterial nanocellulose (BNC), offers the best solution to achieve such material. In this study, a composite membrane comprising of curcumin particles and BNC were prepared using

The major attribute of polyelectrolyte solutions is that all chains are strongly correlated both electrostatically and topologically. Even in very dilute solutions such that the chains are not interpenetrating, the chains are still strongly correlated. These correlations are manifest in the measured scattering intensity when such solutions are subjected to light, X-ray, and neutron radiation. The behavior

Soft polymeric nanomaterials were synthesized by template-assisted method involving condensation of the poly(ethylene oxide)-b-polycarboxylate anions by metal ions into core-shell block ionomer complex micelles followed by chemical cross-linking of the polyion chains in the micelle cores. The resulting materials represent nanogels and are capable of swelling in a pH-dependent manner. The structural

Polyethylene glycol derivatives, such as block copolymers of polyethylene glycol and diacyllipids (for example, phosphatidylethanolamine) are widely used for surface modification of various pharmaceutical carriers in order to impart them longevity in the body. To make polyethylene glycol detachable from the surface of pharmaceutical carrier and facilitate the interaction of the carrier with target