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The mechanisms of the photogeneration and transport of charge carriers in oligomers based on N,N'-dibenzyl-4,4'-diaminophenylmethane and diglycidyl esters of dicarboxylic acids by electrophotographic and time of flight methods are studied. Spectral and field relations for the effectiveness of the photogeneration of holes and oligomer layers with and without addition of CBr4 are studied. The field relations are interpreted within the framework of the Onsager model. The superlinear relation between the hole flight time and sample thickness indicates the disperse character of charge carrier transport. The hole drift mobility amounts to 2 x 10−10 m2/V s, and the mobility activation energy is 0.25 eV at F = 8 x 107 V/m.

The effect of photochemical sensitization of electrophotographic layers based on linear polyadducts of aromatic amines with diepoxides under electrophotographic conditions is studied. The effect of the electric field intensity, the temperature, and the dielectric permeability of the medium and the layer thickness on the transport of charge carriers in films of polyadducts of different structure is studied by a direct transit time method. The drift mobility of holes, the value of which for the polyadducts studied is within the range 10 −10 −10 −11 m 2 /Vs is inversely related to ϵ. The photovoltage properties of the metal/polyarylamino adduct interface are studied. The efficiency of the transformation of light energy into electrical energy is 6 × 10 −4 %.

Photosensitive polymers investigated in the past few years in relation to problems of electrophotography and photolithography, large-scale phototechnological processes realized in practice, are reviewed. Polymeric photosensitive systems are analysed giving electrophotographic layers with a sensitivity >100 m2J. Promising photoresists are considered based on photocrosslinking and photodegradation of polymers, Fries photorearrangement, photo-initiated acid catalysis of crosslinking and degradation of polymers and phototransformation of non-polar polymers to polycationic compounds.

The dispersion transport of holes in polyarylenovinylenes resulting from electron jumps between blocks of conjugated polymer is studied by a flight-time method. The spread of charge carrier flight times is decreased on introducing hetero-atoms into the macromolecule structure. The drift mobility of holes in poly(1,4-phenylene-1,2-dimethoxyphenylvinylene) is 1.5 × 10−5 cm2/V s and the mobility activation energy is 0.27 eV for an electron field intensity of 5 × 105 V/cm. The electrophotographic sensitivity of polyarylenovinylene films is equal to 1.5–2.0 m2/J in the region of its own absorption (λ < 450 nm).

The pyroelectric properties of PTFE have been measured to throw light on electrical polarization of the polymer. In view of the apolar nature of PTFE polarization takes place both on account of the injection of charges and in presence of an applied field giving rise to the orientation of molecules which have dipole moments due to various types of structural irregularity. Samples with varying degrees of crystallinity were examined. The pyroelectric signal is strongest for the samples with lower degrees of crystallinity. The maximum value of the pyroelectric coefficient is 0·8 × 10 −9 coulomb/cm 2 ·deg.

It has been shown experimentally by the transit-time method that the drift mobility of holes in polyphenylene sulphide is equal to approximately 10−4 cm2/V·sec and depends on temperature in accordance with an activation law. The introduction of electron-acceptor additions into the polymeric matrix somewhat reduces the mobility value but does not affect the activation energy. The dispersion transport of charged carriers is discussed within the framework of a model involving transfer with repeated capture in traps having a continuous distribution with respect to their energy. The possibility of sensitizing polyphenylene sulphide in the visible region of the spectrum has practical importance in connection with the fact that the photovoltaic effect is observed at the metal-polymer junction.

A kinetic study has been made of the attainment and decay of electrical conductivity induced in polystyrene irradiated with accelerated electron pulses. The behaviour of the rapid and slow constituents of the delayed component has been investigated, whilst varying the electric field. The effect of the irradiation dose on electrical conductivity induced in strong electric fields (⩾ 5 × 105 V/cm) has been ascertained. The computer calculations show that the rapid constituent of a delayed component with a hyperbolic decay constant of 0.2 μsec may be accounted for satisfactorily in the framework of the Rouse-Fowler model, provided that the traps are small enough (liberation times not exceeding 100 nsec).

The film-forming aromatic polymer-poly(diphenylamine)sulphide-soluble in N-methyl-pyrrolidone, hexamethapol and DMSO has been obtained by polycondensation of diphenylamine with sulphur in bulk in presence of AlCl 3 at 225°C. The structure of the polymer has been demonstrated by IR, 1 H and 13 CNMR spectroscopy and mass spectrometry. The electrical and photo-electrical properties of the film samples of poly(diphenylamine) sulphide obtained have been studied in detail.

An “inverse” photo-chromism (photo-decolourization) has been found in the case of indolinospiropyranes having an electron donating substituent in 6′- and any other type of substituent in 8′-position in polar solvents and polymeric matrices. The quantum yield of the photo-decolourization in visible light has been found to increase with the spiropyrane content. Rapid spectroscopy confirmed the existence of a pigmented form in a photo-excitation of stereo-isomers.

The mobility of the charge carriers has been investigated for a number of polymers by the flight-time method at room temperature. It is shown that in PS it is the holes that are mobile and in PETP the electrons. The absolute values of the drift mobility measured in the polymers indicated in the regime of dispersion transport are low even in strong electric fields ∼ 10 8 V/m and higher (∼ 2 × 10 −13 m 2 /V·sec). The results are well consistent with the data on the effect of additives on the non-steady radiation electrical conductivity of the polymers studied. In polypyromellitimide, PE and PTFE the mobilities are even lower and in them conductivity through the geminal pairs dominates.

Radiation-pulsed electrical conductivity levels have been investigated for a wide variety of polymeric materials. It is shown that a reduction in the degree of crystallinity or the presence of side polar groups in the monomer units of a polymer (involving a consequent increase in the dipole moment of the latter) results in a lowering of the instantaneous conductivity component. It is proposed that the regularities observed stem from the probability of capture of charge-carriers increasing as the amorphous phase content and the dipole moment for a monomer unit are increased. In slightly polar polymers as opposed to apolar some amplitude increase is observed for the delayed component as well as a reduction in the semi-decay time.

A crystal counter was used to determine values of ʌμτ (ʌ is the radiation yield of charge carriers, μ, microscopic mobility; τ, life time of the quasi-free charge carrier) for PE with different degrees of crystallinity and PMMA. Relations between ʌμτ and temperature were also examined for PE. It was established that the degree of crystallinity and temperature have a slight effect on the value of ʌμτ. On transition from PE to PMMA the value of ʌμτ decreases by one order of magnitude. It was shown using PS that molecular weight Mυ has a slight effect on radiation electrical conductivity σr while increasing it from 105 to 107. A correlation was derived between the variation of material density (as a result of pre-treatment and compression) and the variation of the value of σr.

A kinetic study has been made of the attainment and decay of electrical conductivity excited in a polyimide irradiated with fast electron pulses (particle energy 8 MeV, 40 nsec and 2 μsec pulses). It has been found that the delayed component of the radiation induced electrical conductivity consists of fast (τ12=150 nsec) and slow (τ12=2 μsec) components. It is proposed that the fast component is related to a rearrangement of captured charges from shallow to deeper traps, while the slow component is responsible for the experimentally observed inhomogeneous character of the recombination of charge carriers created in the polyimide by irradiation. It is shown that relaxation of induced electrical conductivity after the cessation of irradiation is not a function of the electric field voltage. An estimate of the captured charge drift mobility at room temperature gives μdr=3·6×10−7 cm2/W·sec.

To determine specifics of aromatic polyimides as a new class of polymeric photoconductors, spectroscopic and photoelectric properties of two soluble aromatic polyimides were examined. These polyimides differ in the bridge group in the diimide fragments. The photoconductivity of polyimide films and its spectroscopic distribution, kinetic features of increase and decay of photocurrent were examined with continuous and impulse (third harmonic of a neodymium laser) light, according to light intensity, electric field strength and temperature. Possible mechanisms of forming and transferring charge carriers in polyimides were investigated.