- In this method, polymerization is done through free radicals, which is done in both hot and cold states. The product obtained by cold method in the presence of oil or in the presence of oil-soot has high linearity, narrow molecular distribution, high molecular weight and difficult processing. (Series 1500 (Type 1500)). The product obtained by hot method is also highly branched and has a wide molecular mass distribution, good process ability and higher 1 and 2-vinyl percentages. (Series 1000 (Type 1000)
- Solution method : In this method is ionic polymerization, the product of this method has high linearity, high flexibility and high abrasion and tear resistance against dynamic stresses.
- Gel method : The product of this method has a weak percentage of chemical bonds during the polymerization reaction between the chains, which reduces the mobility of the chains and improves process ability. The gel is obtained in two ways: 1) Increasing the polymerization temperature. 2) Increase substances such as di vinyl benzene.
Types of additives
Soot dominance is added to the SBR to increase tear and tensile strength. The more soot added, the more black the tire burns with black smoke and the more carbon particles it burns. Silica or titanium oxide may also be added to increase strength and stiffness. Filling can be reduced by using fillers such as plaster, lime or clay.