Obtaining and using of reclaimed butyl rubber with the use of ionizing radiation

Properties of rubber compounds and vulcanizates obtained on the basis of irradiated butyl rubber (sulfur cured or resin cured) have been studied. The irradiation was carried out by a beam of accelerated electrons with doses of 20–100 kGy. Mooney viscosity and network density of the regenerates were investigated. It has been shown that during irradiation the destruction occurs mainly due to the breaking of the carbon-carbon bonds in the main chain. Mechanical processing of the obtained reclaimed rubbers was carried out at temperatures of 70–110 °C and rotors speed of 20‐40 rpm. Mechanical treatment of sulfur reclaimed rubbers obtained at low doses of radiation (40 kGy) ensures a reduction in Mooney viscosity by 2 times, at large doses of radiation - by 1.5 times, at average doses of radiation of 50–70 kGy - by 1.7 times. The residual density of crosslinking is lower for sulfur reclaimed rubbers. Analysis of rheometric test data for rubber compounds based on reclaimed butyl rubbers showed that with increasing of irradiation dose the minimum and maximum torques decrease, the thermoplasticity of rubber compounds increases and the vulcanization rate decreases slightly. In the study of the stress-strain properties of vulcanizates found that the dose of 50–70 kGy provides optimal technical properties. The regenerates (resin cured) was tested in the rubber compound formulation for the manufacture of an innerliner of tires. Analysis of the kinetic parameters of vulcanization showed that the addition to the rubber mixture of 10–20 weight parts of reclaimed rubber has almost no effect on the rate of vulcanization. Stress-strain properties and aging resistance of rubber with reclaimed rubber conform with control standards. •Carbon-carbon bonds in the main chain is break during irradiation of butyl rubber.•Mooney viscosity of butyl rubber decreases with increasing radiation dose.•Degree of destruction of butyl rubber cured by resin and sulfur is about the same.•Curing rate does not change with the addition of 10 per cent of butyl-regenerat.•Dose of 50–70 kGy provides optimal mechanical properties for butyl rubber.