No abstract available

No abstract available

[en] The electret properties of polymer mixtures, components of which do not chemically react with each other, essentially depends on the concentration ratio between the components. In this paper it was studied the effect of gamma irradiation on high density powders from polyethylene and polytetrafluoroethylene on electret properties of the films and blends of these polymers

[en] Photoluminescence properties of composite materials on the base of polypropylene with CdS nanoparticles have been studied in the range of λ=300-1000 nm. ASM investigation shows that preliminary electrodischarge treatment of polymer powder on air has an effect on CdS nanoparticles concentration in polymer matrix due to formation of additional centres of CdS nanoparticles nucleation. Moreover, electrodischarge treatment increases the intensity of photoluminescence peaks

[en] Full text: The progress of radiation technology, monitoring of surrounding, radiation ecology raise the new task in dosimetry. The many dosimetry materials and primaries exist. Its classify on thermoluminescent, chemical, film, semi - conductor and other. The major demands are showed to its are high sensitivity to various forms of alpha, beta, gamma and neutron radiations, expansion of below and upper limits of measurable doses ,exactness and reproduction of results .The design and cost price are account. The new high sensitive electret films from copolymers vinilidenftorid and tetraftoretilen elaborate in laboratory of Institute of RP NASA. It is established that surface density of electret charges se (C/m2) under action g-radiation reduce in the dependence of dose g- radiation D (kGy) as linear low : sigmaP/sigmaE=const-lgD, sEsP-density of charge before and past radiation. The coronaelectret properties of P (VDF+TeFE) films with thickness about 0,5-1 mk,which receive from solution dimetilformamid conservate a line dependence de from logarifm of value of fadiations dose lgD in the interval 0,05-50 kGy for g-quantum which has energy 1,17 MeV by source of Cobalt-60. The coronaelectret films are PET-teflon and polistirole more acceptabile in the doses interval 10-700 kGy. The electret polymer films for g-dozimetry are excel by economy, technology and ecology. The cause of change se in the electret is the two competition process; the first is formation of neutral traps in the polymer with energy 0,4-1,5 eV of molecular and radical nature and its have positive affinity with electron or hole. The second cause is generation of charged particle and its stabilization in the deep traps of structural origin or its transference in the electrons field with following compensation by electret charges

[en] Influence of γ-irradiation and high humidity of medium on the process of electret charges relaxation of polyethylene terephthalate (PETP) films are studied. Samples were irradiated by ⁶⁰Co source on MRX-γ-20 installation, and water absorbability was determined as difference of sample weights before and after holding at 95% humidity. It is shown, that γ-irradiation leads to water absorbability rise. It is established, that γ-irradiation in 10 Mrad dose results in increasing of surface conductance and wetting angle values. It is pointed out, that decrease of thermostimulated current intensity at high temperatures may be the measure of γ-irradiated PETP film humidity resistance

[en] The electric properties of LDPE/CdS nano-composites obtained by method of film oriented stretching previously modified by gamma-radiation influence have been investigated. It is shown that changes in nano-composite dependences with modification different doses by previous gamma-irradiation are the result of molecular segment mobility difference of oriented crazed regions and differences of radiation process velocities in the structure of oriented polymer matrix. HDPE/CdS nano-composite thermo-treatment leads to stabilization of structural and energy states of charge carrier active centers because of filler penetration into matrix volume. The polymer composites with semiconductor nanoparticles have wide physi-mechanical characteristics and high electro-active properties. Characteristics are caused by polymer matrix and properties are supplied corresponding fillers

[en] Full text : There are two fundamental reasons of radiating contamination of the environment: 1) environmental contamination by application of neutron logging with a big doze of radioactive isotopes during oil-gas extraction; 2) disintegration and output of radioactive elements (U, Ra, Th, K, etc.) through geo tectonic breaks of the surface. Devices with the help of which the level of radioecological impurity of an environment was defined on these areas are shown. Also mathematical models (formulas, schedules on dependence between contamination of environment and quantity of radioactive elements) promoting to revealing of new oil-gas deposits and to definition of degree of radioactive pollution in the given territories have been made

[en] Full text : Gamma-irradiation influence on electrophysical properties of polypropylene composites of /α-Fe₂O₃ has been studied. The bounds of electrical properties of composites PP-Fe₂O₃, which have depended on structural changes in polymer matrix and interface interlayer occurring within gamma-irradiation have been established

[en] Full text : Fluoropolymers are known, as one of the most promising polymers of electro active materials and they are very sensitive to radiation, with the prone to decomposition processes. One way to stabilize the piezoelectric properties of Fluor polymers may be their radiation modification of gamma-irradiation. The aim of the present work is to study the effect of gamma-irradiation on the piezoelectric properties of the copolymer of vinylidene fluoride with tetrafluoroethylene-P (VDF-TeFE). The polarization produced in the optimal range for the electric field. Irradiation of the films performed at the facility Rahm-gamma-30 both before and after polarization. For gamma irradiation, apparently as a result of conformational transitions alpha and beta is a change of relations of ferroelectric and par electric phases in upward of crystallinity, i e an increase in the ferroelectric polymer. It was discussed possible mechanisms of changes in the dielectric, piezoelectric and ferroelectric properties (hysteresis loops, the values of the coercive field) with a residual polarization of Fluor polymers when exposed to gamma-irradiation.