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1
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Magnetic Properties of Conducting Polymers

100%
Aksimentyeva O., Artym V., Melnik O., Plusnina T.
Acta Physica Polonica A
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1994
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vol. 85
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issue 1
237-240
EN
Magnetic susceptibility, electroconductivity and structure of polymer conducting layers of polyaniline and polyaminophenoles were studied in a wide temperature range. It was found that magnetic susceptibility depends on the doping level of polymer and the nature of doping agents. The obtained result suggested the existence of metallic states in highly doped conducting polymers.
2
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Positron Annihilation in Chloropolystyrenes

100%
Baranowski A., Dębowska M., Jerie K., Mirkiewicz G., Rudzińska-Girulska J., Sikorski R.
Acta Physica Polonica A
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1993
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vol. 83
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issue 3
239-249
EN
Results of angular correlation of annihilation radiation and positron annihilation lifetime measurements are presented for atactic polystyrene and chloropolystyrenes. The inhibition of positronium formation follows the chlorine introduction as the decrease in intensities of the narrow component in angular correlation of annihilation radiation curves and of the longest-lived component in positron annihilation lifetime spectra prove. In general, the chlorine "activity" towards positrons seems to depend on its position in the polymer structure. The annihilation rate distribution as well as the radius and volume distributions of free-volume sites where positronium is assumed to be formed obtained with the use of CONTIN program for the raw sample in the 2nd series are given additionally.
3
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Liquid Crystalline Polyurethanes Studied by Positron Annihilation Method

100%
Baranowski A., Dębowska M., Jankowski A., Jerie K., Penczek P., Rudzińska-Girulska J., Szczepaniak B., Wolińska-Grabczyk A.
Acta Physica Polonica A
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1995
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vol. 88
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issue 1
21-27
EN
A series of liquid crystalline polyurethanes of different both flexible spacer length and mesogenic group content was studied by means of positron annihilation method. The investigated polymers were targeted on the sep­aration of aromatic hydrocarbons from their mixtures with aliphatic ones. The effect of modification of the liquid crystalline polyurethane chain on the polyurethane free volume size and free volume distribution was determined on the basis of the positron annihilation lifetime spectra. In the positron annihilation lifetime spectra measured for the samples under study two long com­ponents of several nanoseconds, characteristic of o-Ps decaying by pick-off, occurred. The correlation of the values of the o-Ps lifetime with the size of the free volume region allowed to recover the free volume distributions with the use of the method employing the numerical Laplace inversion technique. The obtained results were compared with the diffusion data on the mobility of liquid hydrocarbons in the liquid crystalline polyurethanes enabling the correlations between polymer structure and its transport properties to be evaluated.
4
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Positron Annihilation Studies of Styrene-N-X-Phenylmaleimides

100%
Baranowski A., Dębowska M., Jerie K., Rudzińska-Girulska J., Pawełka Z., Sikorski R. T.
Acta Physica Polonica A
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1995
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vol. 88
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issue 1
51-57
EN
Results of angular correlation of annihilation radiation and positron an­nihilation lifetime measurements are presented for five styrene copolymers: poly(co-styrene-phenylmaleimide) and its three derivatives with chlorine as well as for one with the OH group substituted in the benzene ring. It occurs that the chlorine substituted in three different positions in the benzene ring poly(co-styrene-o (or -m, -p)-chlorophenylmaleimide) inhibits the formation of the positronium to different extent. The greatest effect is observed in case of the chlorine atoms substituted in the benzene ring at ortho-position towards the nitrogen atom. In addition, electric dipole moments were measured for N-X-phenylmaleimide units, to check whether their magnitude influences the positron annihilation parameters. On the basis of the present results no correlation between the positron annihilation parameters and the electric dipole moments of the units was noticed.
5
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Free Volume in Epoxy-Coal Resins Studied by Positron Annihilation

100%
Baranowski A., Dębowska M., Jerie K., Kurzeja L., Hennek K., Rudzińska-Girulska J.
Acta Physica Polonica A
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1995
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vol. 88
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issue 1
43-49
EN
In this paper the macroscopic properties of the tetrafunctional epoxy resin (N, N'-tetraglycidyl ether of diaminodiphenylmethane) cured by 4, 4'-diaminodiphenylmethane, were studied. For the system the influence of various curing conditions on the glass temperature was investigated. Results obtained for two compositions: an unmodified one and a modified with coal were compared with information on the free volume given by the positron annihilation technique.
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