INFLUENCE OF THE POLYMERIC BASIS ON THE PROPERTIES OF RUBBER-FIBER COMPOSITES

Purpose . This study investigates the influence of common and special rubbers as a polymer matrix on the stiffness, strength properties of rubber-fiber composites and their resistance to heat aging. Methodology . Rubber-fibre composites were made on the basis of general (isoprene, styrene-butadiene, divinyl) and special (nitrile-butadiene) rubbers. Polyamide, cotton and fiberglass were used as reinforcing fibers. To ensure high bond strength of the reinforcing fibers with the matrix, the chemical modifier m-phenylene-bis-maleimide was introduced into the rubber. Rubber mixtures were made in a rubber mixer. The fibre in the rubber matrix was introduced on the rollers with a gap between the rolls of 1.0 ÷ 1.5 mm. At the end of mixing, the mixture was passed three times through the gap of rollers 0.3 ÷ 0.5 mm without changing the direction of rolling. Vulcanization of the samples was carried out in a hydraulic press with steam heating at a temperature 143 °C and the optimum time of vulcanization. To determine the stiffness modulus of rubber-fiber composites with small deformations (5%, 20%) of tension, the load curve was received (strain deformation dependency) for the sample in the form of a double-sided blade. According to the obtained curve, the tension in the sample corresponding to the strain was determined. Thermal aging of the vulcanizates was carried out in an air thermostat at 120 °C for 96 hours. Findings . The article shows that the reinforcement of vulcanized rubbers based not only on common rubbers, but also on the rubbers of special purposes by short fibres allows significantly increasing their stiffness properties and resistance to heat aging at maintaining the required level of strength characteristics. The maximum stiffness characteristics of rubber-fiber composites were achieved by using a combination of reinforcing fibres. Originality . For the first time, the possibility of creating rubber-fibre composites based on a nitrile-butadiene elastomer matrix with high rates of stiffness, strength properties, as well as resistance to heat aging was shown. Practical value . The obtained results open the prospects for the development of materials for chevron seals and other constructive elements where high rates of not only stiffness and heat resistance, but also oil resistance were necessary.