Mock-up of the system for remote monitoring of the accumulation of hydrogen isotopes in the walls of the Globus-M2 tokamak was assembled and tested. The measurements were performed using the LIA-QMS laser diagnostics (laser-induced ablation with registration using quadrupole mass-spectrometry). The data were obtained on the content of hydrogen isotopes in deposits appearing after exposing tungsten collectors to the loads in the volume of the Globus M tokamak. After testing the diagnostics under laboratory conditions, it was mounted at the Globus-M2 facility. In-situ measurements of the content of hydrogen isotopes in the graphite tiles of the tokamak divertor were performed. The possibility of combining the L-IA‑QMS diagnostics with the LIBS (laser-induced emission spectroscopy) diagnostics has been confirmed, in order to obtain information on the composition of the ablated material. In addition, the LIBS method was used for obtaining the deuterium/protium isotopic ratio during measurements in the Globus-M2 facility.

In this work, oligoimide powder binders of the IDA type based on 4,4’-’oxydiphthalic anhydride and bis-(4-acetamido)diphenyl oxide with different molecular weights were obtained. CFRPs were obtained by electrostatic spraying of a powdered oligoimide binder onto a carbon fabric, followed by high-temperature calendering and hot pressing of prepregs. The thermal and mechanical characteristics of the obtained carbon composites are determined.

The laser-induced desorption (LID) and laser-induced ablation (LIA) methods are compared with each other regarding the possibility of measurements an absolute quantitative analysis of hydrogen isotopes content in first wall materials of fusion reactors. Deuterium containing tungsten films with a thickness of 300–400 nm on a silicon substrate were used as model samples. To implement the LID, the samples were irradiated with laser pulses with a duration of 200 microseconds and an energy density of 50–150 J/cm2, for LIA – 12 ns and 5–15 J/cm2. The registration of residual gases was carried out by quadrupole mass spectrometry. Computer simulation of laser pulse heating was performed for the LID process. The simulation results and experimental data showed that heating at an energy density of 100–150 J/cm2 is sufficient to degas tungsten films of the studied thickness. A comparison of the amount of desorbed deuterium in the LID (150 J/cm2) and LIA (15 J/cm2) modes shows that it is identical within the measurement error and is equal to 4.15±0.15·1014 cm-2.

Composite films of methyl cellulose and poly(urethane-imide) are obtained. At the poly(urethane-imide) content in the films above 50% phase separation of the polymers is observed. Using the methods of dynamic mechanical analysis and X-ray diffraction the structural organization of the films is studied, the temperatures of relaxation transitions are determined, and the mechanical characteristics of the composite films are investigated.

Using the methods of X-ray diffraction and scanning electron microscopy, the structure of composite films based on chitosan and single-wall carbon tubes has been studied. It is shown that the introduction of carbon nanotubes leads to the ordering of the chitosan structure. Increase in concentration of nanotubes (from 0 to 3%) causes rise in the value of storage modulus from 3 to 4 GPa (DMA data), increase in electrical conductivity of samples (from 10-11 to 102 S/m), and some changes in their dielectric permittivity (from 5.5. to 26 at an electrical field frequency of 1 kHz). Data on the ionic and electronic components of the conductivity of the composite film are presented. Keywords: chitosan, electrical conductivity, nanotubes, dielectric constant, composite.

Poly(urethane-imide) copolymers (PUICs) possessing the properties of new-generation thermoplastic elastomers with high heat resistance and mechanical strength were synthesized from polycaprolactone, 2,4-toluene diisocyanate, aromatic dianhydride A, and aromatic diamines. The heat resistance and thermal stability of the PUIC films and moldings, as well as their mechanical properties under dynamic and static conditions were compared. The influence of the type of the samples (films or moldings) on their elastic properties was studied. It was demonstrated that PUICs can be melt-processed under conditions where thermal and shear stresses do not cause noticeable degradation of the polymer, which influences the properties of moldings.

The experimentally tested schemes are presented for the synthesis of copoly(urethaneimides) and related composites with complicated molecular structures: multiblock (segmented) copolymers with enhanced and lowered relative contents of thermodynamically incompatible rigid imide and flexible urethane (polyether and polyester) blocks, composites of copoly(urethane-imides) with graphene and tungsten disulfide nanoparticles, non-segregating mixtures of copoly(urethane-imides) and polyimides, random copolymers of imides with copoly(urethane-imides), and multiblock copoly(urethane-imides) cross-linked via rigid imide blocks based on both one and two polyethers. The synthesized polymeric systems were studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The compositions of the polymeric systems was shown to affect the separation and interaction of polyether and imide microphases, which makes it possible to transit from polyimide thermoplastics to copoly(urethane-imide) thermoelastoplastics.

Using the methods of X-ray diffraction and scanning electron microscopy, the structure of composite films based on chitosan and single-wall carbon tubes has been studied. It is shown that the introduction of carbon nanotubes leads to the ordering of the chitosan structure. Increase in concentration of nanotubes (from 0 to 3%) causes rise in the value of storage modulus from 3 to 4 GPa (DMA data), increase in electrical conductivity of samples (from 10-11 to 102 S/m), and some changes in their dielectric permittivity (from 5.5. to 26 at an electrical field frequency of 1kHz). Data on the ionic and electronic components of the conductivity of the composite film are presented.

Multiblock (segment) shape memory poly(urethane-imide) copolymers (PUIC) were studied by thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The title polymers were synthesized from 2,4-toluene diisocyanate, aliphatic polyesters/polyethers including poly[di(ethylene glycol) adipate] diol, polypropylene glycol, and polycaprolactone diol, as well as pyromellitic dianhydride and aromatic diamines (m-phenylenediamine, p-phenylenediamine, and benzidine). The PUIC synthesized in this work are derivatives of rigid-chain polypyromellitimides containing no hinge groups and demonstrate high shape recovery rates. The shape memory effect in the polymers studied was assessed from the shape fixity rates Rf and shape recovery rates Rr determined after the third test cycle. The samples characterized by the Rf and Rr coefficients close to 100% were selected. The PUIC films are characterized by the breaking stress in the range of 20–35 MPa and the fracture strain in the range of 600–1100%. By and large, the PUIC studied represent elastomers with high thermal stability, mechanical strength, and thermally initiated shape memory. Molecular design of shape memory PUIC requires that the hard blocks be modified with imide fragments containing no hinge groups while the soft blocks be based on polyethers/polyesters with high segmental mobility.

The rheological properties of dilute and moderately dilute concentrated aqueous solutions of methyl cellulose mixtures with carboxymethyl chitosan are studied. Using dynamic mechanical, thermomechanical, and thermogravimetric analyses and X-ray diffraction the structural organization, thermal stability, and mechanical characteristics of the composite films are investigated, the temperatures of relaxation transitions are determined, and the composition regions in which the polymers are compatible and form mixed structures are ascertained.

Self-supporting films and thick-walled moldings (blades) were obtained from solutions and melts of multiblock (segmental) copoly(urethane-imides). The initial copoly(urethane-imides) were obtained on the basis of aliphatic polyesters: poly(propyleneglycol), poly(diethyleneglycoladipinate) and polycaprolactone, dianhydride of 1,3-bis(3’,4-dicarboxyphenoxy) benzene and aromatic diamines: 4,4’-bis-(4”-aminophenoxy)biphenyl and 1,4-bis(4’-aminophenoxy)diphenylsulfone. Samples of films and moldings were studied by IR spectroscopy, TGA, DSC and mechanical analysis under static and dynamic (DMA) experimental conditions. It is assumed that the diff erences in the properties of films and moldings are due to an increase in the proportion of aromatic blocks due to microdestruction of polymer chains and increased interfacial interactions of polyester and urethanimide microphases (blocks) in polymer systems during the processing of polymers from the melt by injection molding.

Polymer composite materials have high resistance to mechanical and chemical influences. These properties depend on the quantity and properties of the filler. We used boron carbide and tungsten nanopowder as a filler to obtain radiation-protective material. Mechanical properties of the composite decrease with the addition of the filler and it’s density increases. Knowledge of the relation of physical and radiation-protective properties of all possible compositions is required for efficient practical use of composites. The results of physical and mechanical tests represent the whole spectrum of possible compositions of composites based on ultrahigh molecular weight polyethylene. The presented results of mechanical tests allow to optimize the composition of under certain tasks. According to the results of mechanical tests of layed samples can be judged on the degree of degradation of the material in time.

Poly(urethane-imide) copolymers (PUICs) containing reactive carboxyl groups in hard imide segment were synthesized from poly(propylene glycol) with isocyanate end groups, 1,3-bis(3′,4′-dicarboxyphenoxy)benzene dianhydride, aromatic diamines 4,4′-bis(4″-aminophenoxy)diphenyl sulfone or 4,4′-bis-(4″-aminophenoxy)biphenyl, and 3,5-diaminobenzoic acid. The PUICs were covalently cross-linked using reactions of carboxyl groups with aromatic diisocyanates and 1,2,5,6-diepoxycyclooctane. The polymers obtained were studied by thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. It was shown that the structure of the cross-linking agents influences the properties of cross-linked PUICs. Changes in the mechanical loss factor (tg δ) were analyzed vs. chemical structure of the PUICs. The maximum tg δ values of the copolymers studied are in the range of 0.3–0.4, which suggests good damping capacity of these systems.

Multiblock (segmented) copoly(urethane–imides) were prepared using as monomers toluene 2,4-diisocyanate-terminated aliphatic polyether and polyester [poly(propylene glycol), poly(1,6-hexanediol/neopentylene glycol-alt-adipic acid)], aromatic diamines [1,4-bis(4'-aminophenoxy)biphenyl sulfone or 4,4'-bis(4''-aminophenoxy)biphenyl in a mixture with 3,5-diaminobenzoic acid], and 1,3-bis(3',4-dicarboxyphenoxy)benzene dianhydride. Each of the polymers contains two structurally different soft polyether/polyester segments and two identical hard imide segments, into one of which the reactive carboxy group is introduced. The covalent cross-linking of the copolymers was performed by the reactions of the carboxy groups with aromatic diisocyanates (toluene 2,4-diisocyanate, biphenylmethane 4,4'-diisocyanate) and 1,2,5,6-diepoxycyclooctane. The cross-linked polymer systems obtained were studied by thermal gravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The kind of cross-linking agent influences the properties of cross-linked copoly(urethane–imides). Variation of the mechanical loss tangent tan δ and width of the temperature interval of the transition from glassy to rubber-elastic state in relation to the chemical structure of copoly(urethane–imides) was analyzed. For the polymers under consideration, the maximal tan δ values exceed 0.3, which indicates that these polymers exhibit the damping ability.

The effect of carbon nanofibers introduced into the polyimide matrix on the mechanical properties of initial nanocomposite films and nanocomposite films oriented by uniaxial drawing at various stages of polyimide synthesis is studied. It is demonstrated that the storage moduli of nanocomposite films are higher compared to initial polyimide films at equal draw ratios. The self-orientation ability of the studied samples drawn at the stage of a prepolymer (poly(amic acid)) during thermal imidization is revealed, and it is shown that this ability increases upon the introduction of carbon nanofibers into the polyimide matrix. It is found that the polyimide films with the highest rigidity of macromolecules among the studied structures exhibit the highest storage moduli owing to their high self-orientation ability. Using X-ray diffraction and electron microscopy, a change in the supramolecular structure of rigid-chain polyimide films upon their orientational drawing at various stages of synthesis is investigated.

A review of the works performed at the Institute of Macromolecular Compounds, Russian Academy of Sciences in the field of multiblock copoly(urethane–imide)s, a relatively new subclass of thermally stable polymers, is presented. The synthesis of the representative family of copoly(urethane–imide)s different in the chemical structure and ratio of flexible polyester/polyether and rigid urethane–imide blocks is performed. Mixed compounds composed of synthesized copoly(urethane–imide)s and thermoplastic polyimides are obtained. The effect of the chemical structure of the flexible and rigid blocks and their ratio on the glass and melting transitions of the studied polymer systems is investigated. Polymer systems that form stable melts and are suitable for processing to thick-wall products, thermoplastic elastomers, are proposed.

Based on poly[di(ethylene glycol) adipate] ( M n = 2500) terminated by 2,4-toluene diiso-cyanate (TDI), bis(3´,4-dicarboxyphenoxy)benzene (dianhydride R), and 1,4-bis(4´-amino-phenoxy)biphenyl (diamine ODFO) a number of co-poly(urethane-imide) samples with the general formula (R-TDI-2500-TDI-R)(ODFO) n ( n = 1–3, 5), differing in the content of aromatic blocks (from 37 to 65 wt.%) were obtained. The synthesized samples were characterized by the TGA, DSC, and DMA methods and were used to prepare mixed compositions with the known R-ODFO polyimide in two versions, namely, with a polyimide content of 10 and 90 wt.%. Mixed compositions were investigated by DSC. The effect of an increase in the relative content of imide units on the glass transition and melting temperatures of the crystalline phase of copolymers and mixed compositions is detected.