Classification of SBR and its advantages and disadvantages

SBR is a kind of synthetic rubber which was industrialized in early time. At present, low temperature emulsion SBR accounts for about 80% of the total SBR. Then there are SBR black mother rubber, oil filled SBR, high styrene SBR, hydroxy SBR and liquid SBR.

At present, the production of SBR (including latex) accounts for about 55% of the total production of synthetic rubber, which is a kind of rubber with a large output and consumption.

Advantages and disadvantages of SBR:

SBR is an unsaturated hydrocarbon polymer with solubility parameters of about. Physical and chemical reactions will occur under the action of light, heat, oxygen and ozone, but the oxidation of the reaction is slower than that of natural rubber, even at higher temperature. Light has no significant aging effect on rubber, but its ozone resistance is worse than that of natural rubber. Brittle temperature is about 45 below zero °， The low temperature performance is slightly poor.

Compared with general rubber, it has the following advantages and disadvantages:

1. Advantages

(1) The rubber is not easy to scorch and sulfur, and the vulcanization flatness is good.

(2) The wear resistance, heat resistance, oil resistance and aging resistance are better than that of natural rubber. High temperature wear resistance is good, suitable for passenger tire.

(3) The molecular weight of the process will not be reduced after it is reduced to a certain extent, so it is not easy to be refined and the plasticity is even. The hardness of vulcanizate changed little.

(4) The molecular weight can be increased to high filling. The processing performance of oil filled SBR is good.

(5) It is easy to use with other unsaturated general rubber, especially with natural rubber and cis-butyl rubber. The shortcomings of SBR can be overcome by formula adjustment.

2. Disadvantages

(1) The strength of pure glue is low, and it can be used only when high activity reinforcing agent is added. The difficulty of adding mixture is bigger than that of natural rubber, and the dispersibility of the mixture in rubber is poor.

(2) The structure of trans type is more, the structure is irregular, and the benzene ring is on the side base, so it has a great lag loss, high heat generation, low elasticity and poor cold resistance. But when filled with oil, it can reduce heat generation.

(3) The vulcanized rubber has the advantages of large shrinkage, low strength and less adhesion performance than natural rubber.

(4) The vulcanization rate is slower than that of natural rubber.

(5) The vulcanizate has better resistance to cracking than natural rubber, but the crack propagation speed is faster. The thermal tearing performance is poor.