Butadiene rubber (BR) is commercially available in two main forms. One contains 1,4-cis repeating unit levels at around 40 percent, which is called low-cis BR. And the other with levels that range from 92-98 per- cent, called high-cis BR.
Moreover, high-vinyl polybutadienes may be obtained, which contain pendent vinyl groups as a result of 1,2-polymerization mechanisms. These rubbers had properties similar to those of SBR and are used with a specific compounding strategy.
This paper reports an overview of several different polybutadienes with different molecular architecture and related property-structure relationships. Functionalization, being a chemical parameter, is not taken into account. In addition, besides traditional BR grades, new Nd-based polybutadienes containing a specially designed molecular architecture are introduced, to optimize processing and performance at the same time.
The molecular architecture able to conjugate those extremely different aspects is discussed on the basis of the linear viscoelastic response. By considering various recipes, advantages in extrusion behavior and hysteresis are addressed together with commonly used testing parameters.