INVESTIGATION OF THE INFLUENCE OF POLYISOBUTYLENES ON THE PROPERTIES OF SEAWATER-RESISTANT RUBBER

The influence of polyisobutylene of grades P-30 and P-200 on the rheometric, physico-mechanical and dynamic properties of rubber used for manufacturing the products exposed to sea water has been investigated. The rubber compound included: butadiene-styrene DSSC-628B and chlorobutyl KhBK-139 rubbers, vulcanising agent (sulphur), vulcanisation accelerators (2,2′-dibenzthiazole disulphide, guanide F), vulcanisation activators (zinc white, stearic acid), antioxidant (N-phenyl-2-naphthylamine), softeners (rosin, petroleum bitumen, factis), fillers (trans-polynorbornene, carbons black (P 514, P 803), and natural chalk). As a result of the studies, it is established that with an increase in the content of polyisobutylenes from 5 to 20 phr a change in the physico-mechanical properties of rubber is observed (a decrease in tensile strength, hardness, and tear resistance), while the relative elongation at break and the dynamic properties of rubber increase. Moreover, with polyisobutylene content up to 15 phr, the physico-mechanical properties of rubber change within acceptable limits, but at 20 phr these properties deteriorate sharply. Vulcanisates containing polyisobutylenes P-30 and P-200 up to 15 phr exhibit smaller changes in physico-mechanical properties and mass after exposure to sea water. It has been determined that rubber containing 15 phr polyisobutylene P-200, due to its physico-mechanical, performance and dynamic properties, can be recommended for the manufacturing the products operating under exposure to sea water.