Modified fluororubbers based on SKF-26: Relaxation and mechanical properties

Samples of SKF-26 fluororubber modified by incorporating pendant methoxy groups into the macromolecular chain were studied by dielectric spectroscopy and dynamic mechanical analysis.     

Electrophysical Properties and Thermal-Deformation Stability of Composites Containing Polyaniline Layers Deposited on Porous Polyethylene Films

The conducting properties of composites prepared by deposition of polyaniline layers on the surface of porous polyethylene films from dispersions and by polymerization in situ were studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 484–489.Original Russian Text Copyright © 2005 by Kuryndin, Mokreva, Terlemezyan, Sidorovich, Praslova, Elyashevich.     

Effect of crystalline phase on the elasticity of rubbers

The dynamic mechanical properties of crystallizing divinyl and isoprene rubbers have been investigated over a wide temperature range. It is shown that the formation of a crystalline phase in the rubber leads to a regular increase in rebound resilience in the transition temperature range. The demonstrated relation between these quantities shows that the minimum elasticity can be used as a measure of the crystalline phase present in the polymer.Mekhanika Polimerov, Vol. 1, No. 3, pp. 15–20, 1965     

Properties of Conducting Composite Systems Containing Polypyrrole Layers on Porous Polyethylene Films

Conducting composite systems containing polypyrrole layers were prepared by in situ polymerization of pyrrole on the surface of porous polyethylene films. The polymerization was performed in the gas phase, in a monomer solution, and in supercritical CO₂. The chemical structures, electrical conductivities, and mechanical, thermodeformational, and morphological characteristics of the composites obtained were compared.     

Collective processes during stimulated light scattering

An approach to the analysis of the phase conjugation by stimulated light scattering that is alternative to the mode theory of 3D hologram, which is usually applied for these purposes, has been studied. As is known, the use of the mode theory is based on the phenomenological gain factor of the Stokes wave, which is induced by a pump wave in a nonlinear medium. The approach developed in this work directly considers the interaction between plane components of the pump and Stokes waves via hypersonic gratings of the dielectric permittivity, which the pump and Stokes waves induce in the medium. It has been shown that, as a result of the phase conjugation, two hypersonic gratings participate equally efficiently in the interaction between any pair of plane components of the pump and Stokes waves, with one of these gratings being excited by the interacting waves themselves. The other grating in each such pair is unambiguously identified with a simplest vector diagram. Conditions have been analyzed under which numerous other gratings, which could also participate in the interaction of each pair of plane components of the pump and Stokes waves without violating the Bragg conditions and the joining conditions of the transverse components of the wave vectors at the interface between the two media, contribute negligibly to stimulated light scattering. It has been shown that, if the pump is spatially coherent, the considered approach yields the same results as the standard mode theory does. In October 2011, I reported the results of this work at the Vavilov State Optical Institute at the Memorial Meeting “Half a Century of New Optics in Russia: Lasers, Nonlinear Optics, and Optical Holography” and at the International Conference “Laser Optics—2012” (June 2012).     

Light-sensitive chalcone-containing poly(amido imides)

Soluble poly(amido imides) and copoly(amido imides) containing main-and side-chain chromophore chalcone groups have been synthesized. Thermo-and photocrosslinking of polymer chains in films under UV irradiation have been studied. The mechanical properties, dielectric behavior, and photosensitivity and photoconductivity characteristics of the polymers have been investigated.     

Investigation of physical state and phase behavior of polyester-imides

Changes in properties of linear aromatic heterocyclic polymers of the polyimide class after introduction of ester linkages into their dianhydride component and of the oxygen and sulfur atoms into their diamine component have been studied. Thermomechanical, dilatometric, thermographic characteristics and x-ray diffraction patterns of poly(ester amic acids) and polyester-imides have been investigated. On heating, poly(ester amic acids) and amorphous polyesterimides exhibited a peculiar effect of self-orientation of macromolecules. The x-ray diffraction patterns of unoriented films indicate that they exhibit axial-planar texture with the c axis of macromolecules in the film plane. The formation of the texture is preceded by mutual arrangement of macromolecules, i.e., by a precrystallization process beginning in the amorphous state. Because of this, on heating at temperatures ranging from 200 to 380°C, polyester-imides yield highly crystalline products. Crystallographic parameters of the polymer lattices on x-ray diffraction patterns and dichroism of absorption bands in polarized infrared spectra, the most probable conformations of macromolecules of some polyesterimides are proposed.     

Polyamidoimides with side chromophoric groups

A new method was elaborated for the introduction of chromophores into the side chains of polymers by esterification of polyamidoimides containing side carboxy groups with glycidyl ethers of dyes, 4-(4-nitrophenylazo)phenol and 4-(6-nitrobenzothiazol-2-ylazo)phenol. The optimum modification conditions were found that made it possible to esterify 15, 30, 50, and 90% of the carboxy groups. The synthesized polymers possess valuable physicomechanical properties (E = 2.8–3.3 GPa, σ_u = 69–90 MPa, ε_u = 38–77%) and glass transition temperatures of 115–125 °C, depending on the degree of esterification. After chromophore orientation in the corona discharge, all the polymers demonstrate nonlinear optical properties of the second order. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1438–1444, June, 2005.     

The study of the structure of solutions of the H-complexes of diesters of tetracarboxylic acids with diammes by the light scattering method

The process of structurization in solutions of H-complexes of dimethyl 3,3,4,4 -benzophenonetetracarboxylate with 4,4 -diaminodiphenylmethane has been investigated in 90 % aqueous methanol in the concentration range 6 to 0.2 g L^–1. Structural instability of the solutions has been found in the concentration range from 1.2 to 2 g L^–1. The addition of an ionogenic substance stabilizes the solution and results in monotonic changes in the structural parameters as solution is diluted. A tendency toward variation of the extemum in the mean correlation radius of the polarizability fluctuation has been found in the concentration range 0.6-–1 g L^–1, which had been observed previously for polymer systems.For Part 1, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1219–1221, July, 1994.