The modification of cis-1,4-polybutadiene with copolymers of maleic anhydride and α -olefin: the influence of the nature of the α-olefin

摘要

In 2011, the worldwide production of synthetic rubbers exceeded 14 million t [1 ], the proportion of polybutadienes amounting to more than 22%. One of the butadiene rubbers in highest demand is cis-1,4-polybutadiene produced using a neodymium-containing catalytic system. The high processing and service properties of "neodymium" polybutadiene and its vulcanisates are determined primarily by its high stereoregularity. Furthermore, polybutadiene produced using a neodymium catalyst contains no toxic or ecologically harmful oligomers, and the production layout does not incorporate a catalyst residue washing-out stage because neodymium is not an oxidation catalyst. Rubber compounds based on these butadiene rubbers possess high dynamic properties and low hysteresis losses [2-4]. The shortcomings of neodymium polybutadiene include the high cold flow of the rubber, which is determined by the linearity of its macromolecules. This problem is particularly acute in the case of the production of a polymer of narrow polydispersify. This leads to considerable difficulties in the isolation and storage of the rubber [5]. Therefore, work on lowering the cold flow of polybutadiene produced in the presence of a neodymium-containing catalytic system is fairly urgent, as borne out by the unwavering interest of researchers in this question [6-10]. An analysis of the patent literature showed that the most effective method for reducing the cold flow of rubber is to modify the polymer at the final stage of the polymerisation process by the interaction of "living" macromolecules with functional groups of different reactive compounds [11-14].