SBR rubber

Styrene-butadiene rubber (SBR) is a fundamental material for the majority of synthetic rubbers. It is a copolymer derived from butadiene and styrene.

- Crack resistance is lowest at high temperatures; at 100°C, it loses 60% of its crack resistance.
- Heat resistance is poor; at 94°C, vulcanized rubber loses two-thirds of its strength and 30% of its elongation.
- It exhibits significant crack propagation.
- Energy consumption during preliminary processing and compounding is high; prolonged preliminary processing results in reduced plasticity.
- Low plasticity makes mold filling difficult, though plasticity can be improved using additives such as naphthalene oil or rosin.
- Internal heat generation is high compared to natural rubber, leading to significant energy loss in products subjected to repeated flexing or compression.
- The vulcanization rate of SBR is slower than that of natural rubber.