Effect of crystallization on the adhesion of polycaprolactam to metal

The effect of the melt cooling and annealing conditions on the supermolecular structure of polycaprolactam and its adhesion to aluminum has been studied. It is shown that the transition from amorphous-mesomorphous to crystalline structure leads to a decrease in adhesion.Institute of Mechanics of Metal-Polymer Systems, Academy of Sciences of the Belorussian SSR, Gomel'. Translated from Mekhanika Polimerov, No. 1, pp. 170–172, January–February, 1976.     

Effect of processing conditions on the supramolecular structure and strength properties of polycaprolactam

The formation of supramolecular structures in block polycaprolactam is considered. It is shown that technological factors have a considerable effect on the nature of the supramolecular structure. Two of these factors are the temperature gradient of the polymer melt and the nature of its motion in the cylinder of the injection molding machine up to the moment of injection into the mold. It is shown that the nonuniformity of deformation and the considerable number of defects associated with large supraspherulitic formations lead to a deterioration in the strength and deformation properties of polymers.Mekhanika Polimerov, Vol. 2, No. 5, pp. 659–663, 1966     

Effect of the thermal regime on the supermolecular stpuctures and certain ppoperties of polycaprolactam coatings

The effect of the thermal regime on the supermolecular structures and certain physico-mechanical properties of polycaprolactam coatings obtained on heated substrate specimens in a fluidized bed is considered.Division of Polymer Mechanics, Academy of Sciences of the Belorussian SSR, Gomel. L. Ya. Karpov Scientific-Research Physicochemical Institute, Moscow. Translated from Mekhanika Polimerov, Vol. 5, No. 2, pp. 195–200, March–April, 1969.     

Effect of gamma radiation on the cracking and mechanical properties of Kapron (polycaprolactam)

The results of a mechano-optical investigation of irradiated oriented polycaprolactam film are discussed. After irradiation comparatively large cracks running at right angles to the orientation axis appear in the film; these are responsible for the reduced tensile strength and deformability of the polymer.Ioffe Physicotechnical Institute, Academy of Sciences of the USSR, Leningrad; Lenin Tadzhik State University, Dushanbe. Translated from Mekhanika Polimerov, No. 4, pp. 756–758, July–August, 1971.     

Effect of structural-chemical modification of a polycaprolactam block on the retention of strength during thermo-oxidation

The structure and strength of a block of polycaprolactam (PC) have been investigated in relation to diffusion stabilization and thermo-oxidation. It is shown that structural modification of the surface layers of the PC block with zinc iodide has an important effect on the retention of strength during prolonged thermo-oxidation.Kaunas Polytechnic Institute; Institute of Physicotechnical Problems of Energetics, Academy of Sciences of the Lithuanian SSR, Kaunas. Translated from Mekhanika Polimerov, No. 1, pp. 10–14, January–February, 1970.     

Effect of antioxidant distribution in polycaprolactam on the variation of strength and deformability at elevated temperatures

The effect of quinhydrone distribution over the cross section on the strength and deformability at elevated temperatures has been investigated for specimens of polycaprolactam. The optimum concentrations of quinhydrone in the surface layer of polycaprolactam retaining maximum strength over an extended period in a hot-air medium have been determined. The most probable areas of formation and localization of structural defects under thermal action have been established.Mekhanika Polimerov, Vol. 3, No. 2, pp. 296–301, 1967     

Effect of gamma radiation on the mechanical properties and structure of oriented polycaprolactam (kapron)

Mechanical tests and x-ray diffraction measurements at large and small angles indicate that when oriented polycaprolactam is exposed to gamma radiation the "damage" is chiefly concentrated in the amorphous intercrystallite regions.Mekhanika Polimerov, Vol. 4, No. 1, pp. 173–177, 1968     

Effect of aging on the lifetime of industrial polyimide film

Results are given of a study of the thermomechanical properties of industrial polyimide film at constant mechanical-stress values and on nonlinear change in temperature with time. The effect of thermal aging and of irradiation with neutrons on polyimide (PM) film is examined. From the experimental data obtained, the possibility is presented of predicting the "service life" of material over a wide range of mechanical loads and temperatures.S. M. Kirov Polytechnic Institute, Tomsk. Translated from Mekhanika Polimerov, No. 6, pp. 1046–1049, November–December, 1974.     

Fatigue and fracture of stabilized polycaprolactam

We have investigated the effect of certain antioxidants and structure-forming agents on the mechanism and work of fatigue fracture of polycaprolactam under cyclic loading. We have analyzed the super-molecular structures and fracture surfaces of the most typical stabilized specimens and offer an explanation of the fatigue hardening mechanism in stabilized polycaprolactam.Mekhanika Polimerov, Vol. 3, No. 4, pp. 713–718, 1967     

Changes in the fine structure of polycaprolactam induced by hydrostatic pressure

The effect of high (up to 22,000 atm) hydrostatic pressure on the interplanar spacings and corresponding diffraction maxima in polycaprolactam has been investigated. The observations are interpreted in terms of the compressibility anisotropy relative to the amorphous and crystalline regions of the polymer and possible elastic deformation of the amorphous zones leading to tensile stresses in the crystalline regions that relax as the polymer ages owing to processes associated with changes in the conformations of the macromolecules and the number of crosslinks between segments.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, Vol. 4, No. 4, pp. 579–585, July–August, 1968.     

Effect of UV irradiation on the structure of cotton fiber

The effect of UV irradiation on the structure of 5595-V brand cotton fiber was studied. Photodestruction was shown to be accompanied by a reduction in crystallinity.     

Deformation of thin polycaprolactam film in uniaxial tension

The individual stages of deformation of spherulitic specimens of polycaprolactam have been studied by a microscopic method. An empirical relation between the total deformation of the specimen and the deformation of the individual spherulite is obtained.     

Effect of ultraviolet radiation on the lifetime of polymers under load in the low-stress region

In the low-stress region the lifetime of polymers placed under load in the presence of UV radiation is appreciably greater in a vacuum than in air. This indicates that the ambient medium plays an important part in the process of restoration of broken bonds and that the knee on the log =f() curve is at least partly due to recombination processes.Ioffe Physico-Technical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 5, pp. 929–931, September–October, 1969.     

Evaluating the lifetime performance index for the exponential lifetime products

Process capability indices (PCIs) are used to measure process potential and performance. Since the lifetime of products generally may possess an exponential, gamma or Weibull distribution, etc., so under a two-parameter exponential distribution, this study constructs a uniformly minimum variance unbiased estimator (UMVUE) of the lifetime performance index based on the right type II censored sample. Then the UMVUE of the lifetime performance index is utilized to develop the new hypothesis testing procedure in the condition of known L. Finally, a practical example is illustrated to employ the testing procedure to determine whether the process is capable.     

Effect of uv irradiation on the mobility of the molecular chains in polyethylene

Conclusions 1. A decrease in the mobility of molecular chains in polyethylene after UV irradiation was discovered by the spin probe method. This decrease is proportional to the time of irradiation.2. A discontinuity lacking in unirradiated polyethylene was found on the curve for the logarithm of the rotational correlation time of the spin probe in polyethylene as a function of the inverse temperature. It was shown that the nature of the discontinuity is related to a "thawing out" of the rotational motion of the chains in the crystalline phase.Institute of the Mechanics of Metal-Polymer Systems, Academy of Sciences of the Belorussian SSR, Gomel. Translated from Mekhanika Polimerov, No. 4, pp. 603–608, July–August, 1976.     

Effect of starting structure on the lifetime of a polymer under load in the presence of ultraviolet radiation

An investigation of the behavior of the coefficents A_j and _j in the radiation lifetime equation _j=A_je–_j with variation of the starting structure of polycaprolactam has revealed the structure-sensitivity of _j and the structure-insensitivity of A_j. This and the fact that _j is proportional to the structure-sensitive coefficient in the equation for the lifetime without irradiation, together with the previous experimental data, provide a basis for the development of a theory of the mechanism of polymer fracture in the presence of UV radiation and throw light on the physical significance of the coefficients A_j and _j.A. F. Ioffe Physicotechnical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 4, pp. 636–641, July–August, 1969.     

Influence of pre-straining on the lifetime of filled elastomers

Pre-conditioning is usually not considered in classical lifetime prediction analyses. The strong material softening observed in rubber materials, however, makes one expect a strong influence of the pre-conditioning on the lifetime. For this contribution, experimental tests were carried out to verify and further investigate, how the pre-loading affects the lifetime of filled natural rubber. Comparing the experimental results with according simulations using the MOdel of Rubber PHenomenology (MORPH) [1, 2] it is found that even though the simulation shows an extended lifetime with higher pre-straining, the experimental data shows no significant influence of this pre-conditioning. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Effect of electron irradiation on the mechanical and thermal properties of some polymer materials

The effect of electron irradiation on the mechanical properties (deformability) of polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyimide (PI), and Fenilon (Fe) films, as well as the thermal properties (heat conductivity and capacity) of PTFE is studied experimentally. The thickness of the films was 40–50 m. Mechanical tests showed that polyimide films were more resistant to radiation than the other films. The investigation of the changes in the thermal properties of PTFE due to electron irradiation revealed that the phase transitions observed at temperatures of 293 and 303 K in unirradiated PTFE were shifted to lower temperature regions.Abai Alma-Ata State University, Kazakhstan. Translated from Mekhanika Kompozitnykh Materialov, Vol. 34, No. 5, pp. 683–689, 1998.     

Effect of proton-electron irradiation on the strength of a glass-reinforced plastic and its components

The action of protons and electrons on the properties of glass strands under vacuum conditions has been experimentally investigated. The experimental procedure is described. The effects of irradiation, strain rate, and reduced temperature and pressure on the properties of glass reinforcement and glass-reinforced plastics are estimated.Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev; Physicotechnical Institute of Low Temperatures, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Mekhanika Polimerov, No. 4, pp. 755–760, July–August, 1970.