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.     

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.     

Dependence of the dielectric constant on the structure of extruded polyvinylidene fluoride films

The structure of extruded polyvinylidene fluoride films obtained at different die drawing ratios and melt temperatures was studied by X-ray scattering, differential scanning calorimetry, and gravimetry. Their dielectric constant and mechanical properties were examined. The influence exerted by the structure of the amorphous phase and by the molecular weight of the polymer on the dielectric constant of the samples was revealed.     

Preparation and Structure of Polyimides Derived from H Complexes of Benzophenonetetracarboxylic Acid with Diaminodiphenyl Ether

The possibility of using H complexes of dialkyl dihydrogen 3,3',4,4'-benzophenonetetracarboxylates and 4,4'-diaminodiphenyl ether and of polyimides prepared therefrom as polyimide foam materials, carbon-reinforced plastics, and foam composites was examined.     

Calorimetric Properties of Different Kinds of Polymers Containing C60 Fullerene

Transformations of polymers containing C60 fullerene: poly-N-vinylpyrrolidone with the complex and covalent-graft structure, polyphenylene oxide with the complex structure, and polyethylene glycol and polystyrene with beam structure, were studied by differential scanning microcalorimetry. The observed effects were assigned to the change in nanofragmentary topology on heating.     

Dilatometric Characteristics of Polyacrylonitrile in a Mixture with Fullerene C60

Thermal cyclization of polyacrylonitrile, synthesized by anionic and radical polymerization, in films containing 0.5 wt % fullerene C₆₀ and without it was studied dilatometrically in the range 20-400°C.     

Structure, phase (aggregate) state, and optical properties of a new heat-resistant polymer with a nonlinear optical chromophore

A new heat-resistant copolymer (II) with a nonlinear optical chromophore in a side chain was synthesized by the etherification of side hydroxyl groups in chains of silicon-containing poly(o-hydroxyamide) (I) with 4′-{(6-chlorohexyl)methylamino}-4-nitroazobenzene (chromophore) under conditions of phase-transfer catalysis. The structure and phase (aggregate) states of copolymer II were investigated using x-ray diffraction and differential scanning calorimetry. It was shown that the substitution of chromophore molecules for up to 15% of hydrogen atoms in hydroxyl groups of amorphous copolymer I most likely leads to an independent arrangement of the chromophoric groups and the formation of crystal domains. It was established that this ordering substantially affects the stability and efficiency of the nonlinear optical properties of films prepared from copolymer II and is probably responsible for the slow decay of the second-harmonic generation signal in the sample.     

Structure and Transport Properties of Films of Mixed Cellulose Esters

Cellulose acetomyristates of varied composition were studied. The sample volume abnormally increases in high-temperature stretching and after swelling in benzene. Cellulose acetomyristates can be used as membranes for separating aromatic and aliphatic hydrocarbons.     

Thermomechanical properties of composite films of polyacrylonitrile with chitin and chitosan

Composite films were prepared from polyacrylonitrile synthesized by anionic and radical polymerization and combined with chitin or chitisan. The thermomechanical properties of the films were examined. The compatibility of polyacrylonitrile synthesized by radical polymerization with chitosan was studied by DSC over a wide temperature range 140–280°C.     

Thermal Transformations of Polyethylene Film and Porous Membrane on Its Basis

Chemical and structural transformations in heating of extrusion and porous polyethylene films in air and an inert atmosphere are studied by thermal analysis and differential scanning calorimetry.