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The paper proposes a new method for visualizing phase-contrast images of polymeric substances using an X-ray interferometer, which makes it possible to determine some of their properties. In particular, based on a three-crystal (two-beam) interferometer, the refractive index and density of polymers were determined by analyzing changes in interference (moiré) patterns. A special device (phase modulator) was prepared and tested to measure the phase change when it is placed in one of the interfering beams. It is shown that the presence of a sample in one of the interfering beams creates shifts in the moiré pattern fringes relative to the fringes obtained in the absence of a sample. The influence of changing the phase relationship of interfering coherent beams on the interference pattern was investigated. The phase shift was determined experimentally and the unit decrement of the refractive index of the sample was calculated. A special device was designed and tested, which allows to change the radius of a cylindrical polymer wire by stretching it. Changing the interference (moiré) patterns and the corresponding reflexes of the diffracted beams in the interferometer leads to the visualization of a phase-contrast image of the polymer cord, which allows its diameter to be determined with great accuracy.
