Key Engineering Materials Vol. 899

Abstract: Investigated the synthesis of polyphenylene sulfide in the environment of an aprotic polar solvent based on p-dichlorobenzene and p-dibromobenzene according to the nature comonomer rating. Infrared spectroscopy and thermogravimetric analysis of the obtained samples are presented.

Abstract: New tissue-engineered vascular prostheses of small diameter (4mm) based on biodegradable polymer backbone – poly (ε-caprolactone) (PCL) and its composition with poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV/ PCL) were created. The full cycle of surface modification of the backbone with polyvinylpyrrolidone and drugs permitted to increase significantly the atrombogenic and antimicrobial properties of prostheses and provide its effective matrix properties. Both types of the developed constructs are suitable for testing in vivo. The energy characteristics of the prosthesis surfaces at the different interfaces were determined. It was established that the value of the energy of the "polymer, saturated with octane/water" interface can be used as a parameter for predicting cell adhesion and proliferation in the case when it is difficult to determine or to distinguish the energy characteristics of the surfaces of tissue-engineered materials at the interface with air.

Abstract: The reaction of radical copolymerization of N, N-diallylaminocarboxylic acids with vinyl acetate in an aqueous and aqueous-organic medium (a mixture of methanol-water in a ratio of 70:30 mol.%) Obtained copolymers of a statistical nature. It was found that vinyl acetate under these conditions is more reactive than N, N-diallylaminocarboxylic acids. The kinetic laws of the reactions have been investigated and the structures of the copolymers have been established.

Abstract: The transition to a highly productive and environmentally friendly agricultural sector, the development and implementation of systems for the rational use of mineral fertilizers for obtaining safe and high-quality, including functional, food products is one of the main tasks allocated by the President of the Russian Federation V. V. Putin. Due to this decree, the theory of mineral nutrition has received rapid development in recent decades within scientific and technological progress in the field of analytical chemistry and physics, molecular biology, and genetics. Information on various physiological and biochemical functions of plant nutrients has been obtained, and the regularities of the distribution of elements in various parts of plants and fruits (berries) have been also generalized. The main forms of nutrients in the soil and the factors determining the bioavailability of macro and micronutrients have been identified. The aim of this research paper is to produce a biodegradable fertilizer where Azofoska Universal (N16: P16: K16) was uniformly coated within layer size by water-soluble biopolymer through continuous flow reactor V-star. The obtained samples were further tested and compared to well-known American analog slow-released fertilizer TAGROW on berry plants under greenhouse conditions within, berry root plant volume, stress resistance of plants, yield, the resulting fruits were studied for sugar levels using an RHB-32ATC refractometer. Moreover, infrared spectroscopy data for obtained biopolymer coated Azafoska Universal is illustrated in this research.

Abstract: The organic part of bituminous Sands (BS) is a chemical raw material of complex and unstable composition. The physical and chemical properties and composition of this raw material depend on the BS Deposit, the method of separation of the organic part, methods and equipment for analysis. The organic component-natural bitumen-is an oil dispersed system, the dispersed phase of which is formed by high – molecular components-resins and asphaltenes; the dispersed medium is made up of lighter hydrocarbons. It was found that traces of tungsten oxide (V), primary and secondary alcohols, and esters were found in the bituminous rock of the Deposit. It was found that natural bitumen extracted from BS contains saturated hydrocarbons: linear: n-heptane, n-decane and cycloparaffins: 1-phenyldodecane, methylcyclohexane, various primary and secondary alcohols, ketone and esters.

Abstract: Thermogravimetric analyses of the samples were performed on a Q-1000/D derivatograph of the F. Paulik, J. Paulik and L. Erdey system of the MOM company (). The method is based on registering changes in the thermochemical and physical parameters of a substance that can be caused when it is heated by the device. The thermochemical state of the sample is described by the curves: T (temperature), DTA (differential thermoanalytic), TG (thermogravimetric) and DTG (differential thermogravimetric). The last curve is derived from the TG function.

Abstract: In the present work, fibers based on heat-resistant amorphous polyimide brand Ultem-1000 were prepared by melt extrusion. Vapor-grown carbon nanofibers (VGCFs) and single-wall carbon nanotubes (SWCNTs) were used to increase the mechanical characteristics of the polymer fibers. The fibers were characterized by scanning electron microscopy (SEM), thermophysical and mechanical tensile analysis. SEM study revealed very good distribution of the carbon nanofillers throughout the polyimide fiber volume. The mechanical testing of the unoriented nanocomposite fibers showed that the introduction of VGCFs or SWCNTs led to an increase in tensile strength and modulus. High-temperature drawing allows obtaining polyimide nanocomposite fibers with significantly increased mechanical properties (»300 MPa for strength and »4.6 GPa for modulus).

Abstract: The copolymerization of 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) and glycidyl methacrylate via reversible addition-fragmentation chain transfer (RAFT) process was investigated. 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT) was used as chain transfer agent. It is turned out that CPDT and polymeric chain transfer agent obtained based on HFIPA and CPDT provide a good control over molar mass characteristic of copolymers (Đ = 1.05). Reactivity ratios were found to be r₁(GMA) = 1.57 and r₂(HFIPA) = 0.05 by Fineman–Ross model.

Abstract: Polymer composite materials based on thermoplastic polymer and carbon nanoparticles with different axial ratio were obtained by melt technology. The values of the electrical resistance of polymer composites have been determined. Development of a methodology for assessing the parameters of the percolation process: the percolation threshold and the required resistance values of the polymer, to obtain a material with antistatic properties.

Abstract: The synthesis of polyphenylene sulfide in the presence of catalytic systems based on various lithium salts has been studied, and conditions have been identified that accelerate the process and obtain a polymer with a given microstructure. The rheological, thermal, and physicomechanical properties of the obtained polymers were studied and the optimum temperature () and pressure (9-10 atm) were established upon the production of polyphenylene sulfide by high-temperature polycondensation of sodium sulfide and 1,4-dichlorobenzene in a solution of N-methylpyrrolidone, which increase the effectiveness of its synthesis.