SBR or SBS

[andy1985]

Hi, i am currently working in a footwear industry and doing a research on SBR (Styrene Butadiene Rubber) and SBS (Styrene Butadiene Styrene). Been stuck in finding out what are the difference between these two. And they are both suitable for footwear. 1 of the difference that i notice is about their elongation percentage and tensile strength. SBR has higher tensile strength and lower elongation, while the other is vice versa. Can anyone please help me in explaining the other differences? Or are they actually a same kind but SBS is only a more styrene kind of version of SBR?

Thank you!

 

[GrahamBennett]

SBR is a random co-polymer of styrene and butadiene whereas SBS is a block copolymer of the two. SBS is more like a thermoplastic I think.