NOVEL THERMOPLASTIC ELASTOMERS BASED ON PVDF/SKF-32: EFFECT OF COMPOSITION ON TECHNOLOGICAL AND PERFORMANCE CHARACTERISTICS

Abstract

Thermoplastic elastomers (TPE) based on SKF-32 fluorine rubber and polyvinylidene fluoride, PVDF (polyvinylidene fluoride content ranges from 30 to 70% relative to rubber) were investigated. The mixes have been produced by using a Brabender-type rotary micromixer. Such thermoplastic elastomers can be an alternative to traditional oil & fuel resistant butadiene-nitrile-based rubbers and can be used in manufacture of sleeves, hoses and tubes for pumping aggressive liquids and gases, wires/cables insulation, fuel storage tanks, valves, etc. Traditional methods of plastics processing can be used to manufacture this materials. It was established that the crystallinity degree increases with the rise of PVDF content. That fact is confirmed by the IR-Fourier spectroscopy data and differential scanning calorimetry. It was shown that the hardness and strength of TPEs increases with the rise of PVDF content. The tensile stress for TPEs containing 50% or more of PVDF are higher than those for conventional oil & fuel resistant rubber IRP 1078. The obtained TPEs possess high resistance against AI-92 grade gasoline, 80% sulfuric acid, 50% sodium hydroxide, and I-40 oil. They also retain their physical and mechanical properties even after three cycles of reprocessing. The TPE with the 1:1 thermoplastic : elastomer ratio, has been vulcanized using a peroxide vulcanizing system at varying concentrations. The dynamic vulcanization is confirmed by a decrease in the swelling degree of the obtained materials in solvents with an increase in the content of the vulcanizing agent. Peroxide dynamic vulcanization has not lead to a significant increase in physical and mechanical parameters, however, it resulted in an increase in chemical resistance of against aggressive solvents.