A COMPARATIVE STUDY OF THE PROPERTIES OF RUBBER COMPOUNDS FOR VULCANIZATION OF BLADDERS OF SHAPER-VULCANIZERS BASED ON BUTYL RUBBER

Abstract

Comparative assessment was carried out of the properties of butyl rubber samples manufactured by Togliattikautchuk, OOO (I), foreign (II) and domestic (III) manufacturers as well as of the properties of rubber compounds and cured rubber based on these rubbers and used for manufacture of bladders of shaper-vulcanizers (BSV). Viscosity was measured using Mooney viscometer MV 2000 (Alpha Technologies), unsaturation was measured with automatic series titrator Т90 Mettler Toledo. Mass content of antioxidant was defined by means of spectrophotometric measurement (using spectrophotometer SPECORD 40) and molecular mass characteristics were measured by means of gel-penetrating chromatography (using Waters gel chromatograph with Refractive Index Detector Waters 2414). Mass contents of volatile matters and ash were measured by means of gravimetric method and mass content of calcium stearate was defined using trilonometric method (according to the related GOST and ISO standards). Dynamic fatigue strength under repeated deformation as well as physical and mechanical properties was also evaluated. It was demonstrated that all the rubbers studied meet the requirements of standard technical documentation of the manufacturer. Slightly increased unsaturation and higher weight-average and number-average molecular weight are characteristic for I, resulting in higher density of vulcanization network and higher strength values. Therefore, it is more preferable for obtaining the cured rubber for BSV. Cured rubber based on I demonstrated its advantages over II based vulcanizates for such characteristics as «tensile strength» and «strength retention factor after thermal ageing» and advantages over III based vulcanizates for the characteristic «Dynamic fatigue strength under repeated deformation». This allows forecast a high service life of BSV.