EFFECT OF DISPERSION AND PARTICLES MORPHOLOGY ON PERCOLATION PROCESS OF TRIFLUOROCHLOROETHYLENE AND CARBON POWDER MIXTURES DURING THEIR COMPRESSION AND SINTERING

Abstract

The development of physical principles of production and investigation of conducting polymer nanocomposites(PNC) is currently an urgent problem of modern material science. The optimization of significant characteristics of those materials advance them to the front among the materials of the electric destination. They саn be used in the making the elements of electrical heater, electromagnetic shields, strain sensors, electrostatic precipitators etc. In comparison with products which are fabricated from metals and ceramics they have a lot of advantages. PNC possess higher corrosion resistance and low density. They are easy workable, elastic and fatigue-resistant. The manufacturing cost of polymer nanocomposite materials (PNCM) is also low. Traditionally, conductive fillers, such as metallic powders, natural graphite, carbon black etc. are used in PNCM fabrication. The considerable changes of the percolation threshold (Cc) (Ccis the concentration of filler in which the “infinite”cluster is form in polymer matrix and composite material becomes conductive) could be caused by dispersion degree and morphology of the filler particles. Particularly, Cc ≈ 34 vol.% for conductive compositions filled with equiaxial particles of micron sizes [1]. Usually, the addition of large amounts of fillers to polymers results in low mechanical performance of composites. Meanwhile, in a case of PNCMs the value of Cc does not exceed 6 vol.% [2]. Such concentration and nanodimentionality of a conductive component provide even the improvement rather worsening of the mechanical characteristics [3]. Besides the morphology and dispersion of the powder particles, the uniformity of their distribution in mixture, adhesive ability, compacting conditions and their influence on the structural changes in the matrix are the important factors in fabrication of PNCM from powder mixtures. The effect of such parameters on the characteristics of fluoroplastic (FP) – thermo-exfoliated graphite (TEG) PNCMs are here reported