Effect of Ground Vulcanizate Modification Methods on Properties of Oil-Petroleum-Resistant Rubber

In this paper, the influence of the modification method applied to ground vulcanizate (GV) on the properties of elastomeric compositions based on nitrile rubber is discussed. Modified GV has been mixed with the elastomeric composition, which is used for the manufacturing of oil-petroleum-resistant rubber products.The work takes into consideration two types of GV with different chemical nature. The first GV type is rubber crumb produced from end-of-life tires. The second GV type was obtained from rubber wastes based on nitrile rubber. Three methods of the modification are compared in the research: mechanical activation in a planetary ball mill, swelling in a Polyethylene glycol (PEG-400) medium, and the mechano-chemical transformation of GV with PEG-4000. It is shown that depending on the dosage addition of GV modified with PEG-4000 reduce the compression set up for (16.1±0.7%), the strength decreases only by 2.1–8.3%, and the elongation at break increases by 0.8–10.3% compared to rubber without additives.

Investigation of the Dynamic Properties of Seawater-Resistant Rubber

The influence of rubbers, trans-polynorbornene, polyisobutylene P-200 and sevilene on vulcanization characteristics, physical-mechanical and dynamic properties of rubber used for the manufacture of products in contact with sea water has been investigated. It has been established that the developed rubber with a sulfur vulcanizing system based on rubbers SKMS-30ARK, SKN-4065 and BK-1675 with additives of trans-polynorbornene and sevilene 11808-340 has improved physical and mechanical characteristics, resistance to sea water and increased dynamic properties

The study of the possibility of using domestic burnt magnesia in oil and petrol resistant rubber

The article examines the oil-and-petrol resistant rubber mixture of type 7NO-68-1SK based on the combination of BNKS-18AMN grade butadiene-caoutchouc with polychloroprene caoutchouc of brand neoprene W. The effect of replacing imported burnt magnesia brand Remag AC on domestic burnt magnesia technical grade B on the properties of the rubber compound and vulcanizate was studied. The rubber mixture was prepared on a laboratory roll mill LB 320 160/160, and then its standard samples were vulcanized at 150 °C for 30 minutes in a two-story electrically heated press of the VP 400-2E brand. To establish the plasto-elastic properties of rubber mixture on the Mooney viscometer, MV 3000 was determined: the start time of the vulcanization, the time to reach the vulcanization mode, the initial maximum viscosity. To assess the kinetics of vulcanization of the rubber mixture on the rheometer MDR 3000 was determined: the start time of vulcanization, the time to reach the optimum vulcanization, the maximum torque. To assess the physicomechanical properties of rubber, the following were determined: conditional tensile strength; elongation at break; hardness; tear resistance and relative residual deformation under compression in accordance with the standards in force in the rubber industry. To assess the performance properties of rubber, changes in its mass were determined after aging in a mixture of isooctane + toluene, as well as standard liquid SJR–1. It has been shown that the introduction of burnt magnesia technical grade B into the rubber mixture does not lead to technological complications, magnesia is well distributed in the rubber matrix, and the magnesia agglomerates were not found on the rubber mixture sections. Replacement magnesium oxide m. Remag AC on burnt magnesia technical grade B has an impact on the plasto-elastic and rheometric properties of the rubber mixture. However of physicomechanical and operational properties vulcanizates of rubber mixture containing magnesium oxide m. Remag AC and burnt magnesiatechnical grade B, have almost the same values.

Development of Frost-Resistant Rubber Based on Epichlorohydrin Rubber of Hydrin T6000 Brand

The results of development of frost-resistant rubber based on epichlorohydrin rubber (ECHR) of Hydrin T6000 brand of Zeon Chemicals L.P. (USA) are described in the present work. The properties of ECHRs are determined by the nature of the structural units that constitute the macromolecules. The absence of olefinic functionality in the main chain gives ECHR the resistance to heat, oxygen, ozone and other factors. The presence of chlorine causes the high resistance of Hydrin T6000 rubber to the effect of hydrocarbon media (oils, fuels, fats, waxes, solvents), and the presence of oxygen atoms helps to maintain the flexibility and elasticity of materials at low temperatures. Hydrin T6000 rubber has the lowest glass transition temperature (Tgt= -60 ° C) from all the epichlorohydrin rubber brands, high oil resistance, increased heat and ozone resistance, and, therefore, attracts researchers' interest as a promising rubber for the development of frost-resistant rubber with sealing capability. The paper presents the formulation of rubbers based on Hydrin T6000 and the results of studies of their physical and mechanical properties. Analysis of the data revealed that the obtained rubber has excellent frost resistance, increased oil resistance at a satisfactory level of residual deformation after compression and strength characteristics. Thus, Hydrin T6000 has established itself as a promising rubber for manufacturing frost-resistant rubber with sealing function and will provide increased reliability and durability of equipment operation in extreme conditions of cold climate in Russia.