免费观看国产午夜激AV_av狼友国产在线观看_久热中文字幕在线播放_日本精品一区免费中文视频

What is butadiene rubber?

Butadiene rubber is short for Cis-1, 4-polybutadiene rubber, its molecular formula is (C4H6)n. Butadiene rubber (BUtadiene) is a synthetic rubber with regular structure, and its cis-structure content is more than 95%. Depending on the catalyst, it can be divided into nickel series, cobalt series, titanium series and rare earth series (neodymium series) butadiene rubber. Butadiene rubber is the second largest synthetic rubber after styrene butadiene rubber.

Properties of butadiene rubber

1. The molecular structure of butadiene rubber is orderly, and the elasticity is better than that of natural rubber.

2. Butadiene rubber has good low temperature physical properties, cold resistance temperature is lower than -55℃.

3. Elasticity is the best kind of universal rubber. The heat resistance is the same as that of natural rubber, but the heat aging performance is better than that of natural rubber.

4. Tensile strength is lower than natural rubber, styrene butadiene rubber, so add carbon black and other reinforcing agents.

5. Butadiene rubber has excellent wear resistance, small hysteresis loss and low heat generation, which is very favorable for reducing heat generation and permanent deformation of products under multiple deformation.

6. Butadiene rubber does not need to be plasticized before mixing. The extrusion performance of the compound is good and it is suitable for injection molding.

7. Butadiene rubber is sensitive to the change of processing temperature.

8. It is generally needed to be used with natural rubber or styrene butadiene rubber to improve the processing performance.

The production process of butadiene rubber

The process includes preparation and measurement of catalyst, terminator and antioxidant, polymerization of butadiene, gel condensation and rubber dehydration and drying. The polymerization process is almost continuous solution polymerization, and most polymerization devices use 3 ~ 5 reactors in series, with a single reactor volume of 12 ~ 50m. The solvents used and the products produced vary with the catalyst.

1. Using butyl lithium as catalyst to produce butadiene rubber, mostly cyclohexane (or hexane) as solvent. The polymerization system has high catalytic activity, simple process and easy to control the reaction. Generally only mixed with polystyrene resin as modified resin.

2. When titanium or cobalt catalytic system is used to produce butadiene rubber, benzene or toluene is generally selected as the solvent. The cis content of butadiene rubber is high and the physical properties of vulcanized rubber are similar, but the difference is that titanium butadiene rubber has narrow molecular weight distribution and large cold flow tendency.

3. In the production of butadiene rubber with nickel catalyst, aromatic hydrocarbons (such as benzene or toluene) and aliphatic hydrocarbons (such as cyclohexane, hexane, heptane or hydrogenated gasoline) can be used as polymeric solvents, and all can be obtained with high molecular weight, high grade butadiene rubber. The technology of producing butadiene rubber with nickel naphthenate - triisobutyl aluminum - boron trifluoride ether complex as catalyst and extracted oil as solvent (the main technology of rubber production in China).

4. There are three new catalysts: High order (96% ~ 99%) butadiene rubber can be prepared by rare earth catalysts (such as rare earth naphthenate - monochlorodiethyl aluminum - triisobutylaluminum), π-allyl nickel chloride catalysts (such as (π-C3H5NiCl) 2-tetrachlorobenzene quinone) and π-allyl uranium halide catalysts, and the activity and physical properties of the obtained vulcanized rubber are good.

Natural rubber is often mixed with butadiene rubber to prepare rubber products

1. The role of blending

The cold resistance, wear resistance, elasticity and dynamic properties of natural rubber products can be further improved by proper addition of butadiene rubber in the production of rubber products with natural rubber as main raw material. Blending natural rubber into butadiene rubber can improve the roll behavior of butadiene rubber, increase the viscosity, and further improve the tear strength and tensile strength of vulcanized rubber. In practical production, the use of natural rubber and styrene-butadiene rubber to prepare tires can also improve the traction force of tires on wet road surface and reduce the breakage of tires in the late aging period.

2. Use of blending glue

The rubber material used with natural rubber and butadiene rubber can be used to prepare all kinds of automobile tires, conveyor belts, hose, rubber cloth, rubber shoes, etc. It can also be used to produce buffer materials, cold resistant products, sponge rubber, etc. The rubber material has good technological performance, and the finished product has better comprehensive indexes such as mechanical strength, wear resistance, tear resistance and aging resistance. In practical production, natural rubber and butadiene rubber can also be used with appropriate amount of styrene butadiene rubber in the preparation of tire.

Application field of butadiene rubber

1. Butadiene rubber is widely used in tire manufacturing, the produced tire tread.

2. Butadiene rubber is widely used in rubber shoes, tape, cots and so on.

3. Butadiene rubber is widely used in cold resistant rubber products, buffer materials.

4. Butadiene rubber is widely used in the field of printing equipment.