BR stands for “butadiene rubber” and designates, along with SBR (styrene butadiene rubber), the most commonly used synthetic rubber. BR is produced from 1,3-butadiene. The monomers can be connected on both ends (1,4 bonding) or only on one end (1,2 bonding, vinyl group in the side chain) producing diff erent BR types with different properties. The 1,4 bonding can further be classified into 1,4 cis and 1,4 trans, where “cis“ means that the substituents are on the same side of the double bond; “trans” means they are on the opposite side of the double bond.
|DSC 204 F1 Phoenix®
|IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase
|8 min / 3 min / 8 min
|Al, pierced lid
|N2 (40 ml/min)
Polybutadiene or butadiene rubber has both soft and hard segments. For this reason, the above graphic shows a Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition at -101°C (midpoint) in both heatings with a step height (Δcp) of approx. 0.27 J/(g.K) from the soft segments and a melting endotherm with a peak temperature of -5°C from the hard segments. It can be concluded that the sample is mainly a 1,4 cis type.