Chemical Industry: Quickly understand solution polymerized styrene-butadiene rubber

Styrene-butadiene rubberThe structure is as shown in the figure. Its repeating unit consists of a double bond, a phenyl group, a methine group, and a trimethyl group. Composed of methylene groups. The large bond angle of the isolated double bond and the reduction of substituents will increase the flexibility of the polymer. Due to the doping of styrene chain links, the main structure is irregular and the polymer is not easy to crystallize. Therefore, styrene-butadiene rubber has very good flexibility.

Solution polymerized styrene-butadiene rubber (SSBR), referred to as solution polymerized styrene-butadiene rubber, also known as solution polymerized styrene-butadiene rubber, is based on butadiene-styrene as the polymerized unit. It is a random copolymer obtained through anionic solution polymerization in an aliphatic hydrocarbon organic solvent using organic lithium compounds as initiators and polar organic compounds such as ether amines as regulators to regulate the microstructure of the polymer chain.

Related synthetic rubber:

Emulsion styrene-butadiene rubber (ESBR) refers to a copolymer of 1,3-butadiene and styrene synthesized in an emulsion according to a free radical reaction mechanism.

Butadiene rubber (BR) is the abbreviation of cis-1,4-polybutadiene rubber. It is a structurally regular synthetic polymer polymerized from butadiene. Rubber, its cis content is more than 95%.

Synthesis method of styrene-butadiene rubber

The method for synthesizing (low heat generation) solution-polymerized styrene-butadiene rubber includes the following steps:

① In an inert solvent and an organic lithium initiator, perform the first copolymerization reaction of styrene monomer and a segment of butadiene monomer;

②Steps

① Add the second-stage butadiene monomer to the obtained product, complete the feeding of the second-stage butadiene monomer within 10~40 minutes, and then perform the second copolymerization The reaction takes 10~40 minutes; the mass ratio of one-stage butadiene and two-stage butadiene monomers is (30~200): 100;

③ Step

②The obtained active butyl styrene polymerization product is coupled and terminated, and an antioxidant is added.

A simple flow chart is shown below.

Performance and application of solution polymerized styrene-butadiene rubber

Solution-polymerized styrene-butadiene rubber has excellent wear resistance, groove and crack resistance, wet road grip, low rolling resistance, heat resistance and It has good flex resistance after being exposed to high temperatures for a long time. In addition, it has the characteristics of low heat generation during mixing in an internal mixer, small extrusion expansion rate, and high filling amount. It is mainly used in tires.

Solution-polymerized styrene-butadiene rubber has good wear resistance, tensile strength, vulcanization flatness, flex resistance and heat resistance, and is particularly suitable for For manufacturing heat-resistant conveyor belts.

Due to its low temperature resistance, shock resistance and good metal adhesion, solution-polymerized styrene-butadiene rubber is suitable for manufacturing belts, wipers, window frame seals and heat dissipation. hoses and other industrial parts.

In addition, solution-polymerized styrene-butadiene rubber has the advantages of good touch, weather resistance, good resilience and small permanent deformation. It can be used to make raincoats, felts, windbreakers and Air mattress etc.

Solution-polymerized styrene-butadiene rubber has good roller operability, calendering properties, wear resistance and high filling properties. It is widely used in the shoemaking industry and has bright color. , has the advantages of good touch, smooth surface, clear pattern, not easy to lose shape, and moderate hardness.

Solution-polymerized styrene-butadiene rubber can also be used to produce sponge materials with uniform foaming and dense structure.

Solution-polymerized styrene-butadiene rubber also has the advantages of less ash, high purity and fast vulcanization speed. It has developed rapidly in China in recent years.

The development prospects of solution-polymerized styrene-butadiene rubber

Synthetic rubber production distribution is shown in the figure below:

With the increasing emphasis on energy and environmental protection, as the main raw material for environmentally friendly tires, the domestic market for solution polymerized styrene-butadiene rubber (SSBR) has broad prospects. After years of development, China has basically mastered its production technology, but there are still many shortcomings that need to be improved.

Manufacturers are improving the intermittent process on the basis of, it is necessary to actively develop continuous polymerization processes and strive to optimize product performance to promote the promotion and application of my country’s SSBR in high-performance tires.

In addition, my country has accumulated certain experience and foundation in the technological development and industrialization of lithium rubber, which can provide technical support for the large-scale industrial development of SSBR. To improve product performance, technology for low-cost production of SSBR can also be researched and developed. With the vigorous development of my country’s highway network and the popularity of family cars, the demand for high-performance high-speed tires is growing, and the market prospects of SSBR will become better and better in the future.

Solution-polymerized styrene-butadiene rubber is a general-purpose rubber with comprehensive properties between emulsion polymerized styrene-butadiene rubber and butadiene rubber. In practical applications, solution-polymerized styrene-butadiene rubber Styrene rubber has better wear resistance, flex resistance, low temperature resistance and other properties. It also has the advantages of no cold flow of raw rubber, good stiffness of mixed rubber and good tear resistance. Judging from the current application market and product performance, SSBR has greater advantages than the other two rubbers.

However, there is a large gap between the development of SSBR at home and abroad. Therefore, caution should be used when producing and using SSBR. The road level at home and abroad is different. Larger, the usage conditions of the tires are also different. Moreover, the production cost of SSBR is higher than that of ESBR, resulting in higher product prices; in addition, the interchangeability between products produced by different companies is unstable. Unlike ESBR, the same brand can be interchanged well, which has certain limitations.