Styrene-butadiene rubber (SBR), also known as polystyrene butadiene copolymer”>Polystyrene butadiene copolymer. Its physical structure properties, processing properties and product performance are close to natural rubber, and some properties For example, its wear resistance, heat resistance, aging resistance and vulcanization speed are better than those of natural rubber. It can be used together with natural rubber and various synthetic rubbers. It is widely used in tires, tapes, hoses, wires and cables, medical equipment and various rubber products. Production and other fields, it is the largest general-purpose synthetic rubber variety and one of the earliest rubber varieties to achieve industrial production.
According to the polymerization process, styrene-butadiene rubber can be divided into emulsion polystyrene-butadiene rubber (ESBR) and solvent-based styrene-butadiene rubber (ESBR). Polystyrene-butadiene rubber (SSBR).
Emulsion polystyrene-butadiene rubber is composed of butadiene and styrene as the main monomers, together with other auxiliary chemical raw materials, and is polymerized by emulsion method under certain process conditions. First, styrene-butadiene slurry is generated. After removing the unconverted monomers in the slurry, the product glue is produced through processes such as coagulation and drying.
Solution-polymerized styrene-butadiene rubber is composed of butadiene, Styrene is the main monomer. In a hydrocarbon solvent, an organic lithium compound is used as an initiator to trigger anionic polymerization to produce a polymer glue. After adding antioxidants and other additives, it is produced through processes such as coagulation and drying. Product glue.
The raw materials and configurations of the two production methods of solution-polymerized styrene-butadiene rubber and emulsion-polymerized styrene-butadiene rubber are basically the same. The main raw materials are butadiene and styrene, but several processes are required during the emulsion polymerization process. Ten kinds of additives, while solution-polymerized styrene-butadiene rubber only needs alkyl lithium as a catalyst and a small amount of a few additives. The solution configuration is simple and easy to operate. Moreover, the solution-polymerized random styrene-butadiene rubber has a small molecular weight and can be filled with a large amount of carbon black. and ink. At the same time, it does not need to be masticated, has good low-temperature performance, small permanent deformation, does not need to use plasticizers, and is easier to wrap. After adding raw materials, it is easy to form into a strip. The film is very smooth, has small shrinkage, and is easy to process. The process is also safer, and the mixing capacity is much larger than that of latex polystyrene-butadiene rubber.
Improvements in the performance of styrene-butadiene rubber— —Carbon black filling
The organic main structural units of coal include aromatic core centers, side chain functional groups and bridge bonds. Under milder conditions, it can be opened through Friedel-Crafts alkylation reaction The strong hydrogen bonds between aromatic cores weaken intermolecular forces and have little damage to their structures. Ultrafine coal powder is blended with polymers as rigid particles, which can significantly improve the mechanical strength and thermal deformation of linear polymer materials as an anti-fog agent. temperature, reducing the shrinkage, warpage deformation and cost of composite materials, which is a very important aspect in rubber production and processing technology. Since the strength of styrene-butadiene rubber after vulcanization is still very low, carbon black can be used as a filler. Greatly improves the strength of styrene-butadiene rubber.
The coal particles are evenly dispersed in the tensile section of the alkylation-modified coal sample composite material, and the styrene-butadiene rubber composite material has achieved good modification effects. High content When composite materials are filled with carbon black, their tensile fracture is brittle fracture. Compared with carbon black, ultrafine coal powder has larger particle size than carbon black particles and is more easily dispersed evenly in polymers, making it less likely to form bridging phenomena; a small amount of carbon black particles exist in the form of sub-micron aggregates of coating additives. When subjected to external forces, a large number of shear bands will be generated and a large amount of energy will be absorbed, thereby greatly improving the toughness of the composite material.
Styrene-butadiene rubber application outlook
In recent years, the world economy has been weak and rubber demand has grown slowly. On the one hand, new natural rubber resources have grown rapidly, natural rubber inventories have increased, and prices have fallen, which has continued to suppress the price of synthetic rubber. On the other hand, in the next two years, my country’s new synthetic rubber production capacity will continue to be released, and the surplus will further increase. In the future, my country must control investment in synthetic rubber equipment to avoid further overcapacity, especially for styrene-butadiene rubber, which has an obvious excess. At the same time, it is necessary to strengthen product brand research, pay attention to production technology research, and develop high-performance synthetic rubber, such as SSBR, rare earth butadiene rubber, bromobutyl rubber, hydrogenated nitrile rubber, etc. It is necessary to develop thermoplastic rubber products that have both rubber and plastic properties, and improve rubber properties and reduce production costs by introducing third monomers.
References
[1] Lu Jianjun, Zhao Yansheng, Bao Weiren, et al. Ultrafine coal powder filled polymer insulation materials [J]. Journal of Coal Science, 2005(2):229- 232.
【2】Gao Yuekai. Structural performance analysis and physical properties molecular simulation study of styrene-butadiene rubber [D]. Beijing: Beijing University of Chemical Technology, 2013.
【3】 Bai Shu Shulin, Chen Jiankang, Wang Jianxiang. Progress in experimental research on interface mechanical behavior of blended/filled polymer composites [J]. Progress in Mechanics, 2006(4):507-516.
[4] China Synthetic Rubber Industry Overview[M]. China Metrology Press, edited by China Synthetic Rubber Industry Association, 2005
