HIPS / Styrene Butadiene Copolymers 3

[GilPolymers]

Hi all,

Today during a chat w/ some friends at work we end up at the question, which is the difference between HIPS or Styrene Butadiene Copolymer? I would like to share this question with you people to know also what you think about it.

As far as I know HIPS is made out PS blended or copolymerized w/ a rubber like material (usually Polybutadiene) so I assume that Styrene Butadiene Copolymer is also a HIPS. My concer is, should we define the HIPS only when we have PB particles dispersed on a PS matrix and define Styrene Butadiene Copolymer to the case of a copolymer? Since I arrived from work I'm searching info regarding the subject and I still not 100% sure about this definition.

So, thank you for comments...

Cheers

 

[Demon3]

I have worked extensively with these polymers so I can help you with the answer. HIPS and SBS are not the same.

HIPS, as you stated, is polystyrene with rubber particles (polybutadiene) added to improve impact resistance. The rubber particles scatter light and make the HIPS white where the unfilled polystyrene is transparent.

SBS is a copolymer of styrene and butadiene. Both monomers are incorporated in the same polymer chain so there are no blobs of rubber in a PS matrix. Because SBS is a copolymer with no rubber particles it is transparent (there are no domains there to scatter light).

Examples of an SBS are Kraton, Styrolux and Styroflex. They are often soft elastomeric materials whereas HIPS is rigid because the continuous phase, polystyrene, is rigid.

If you are not a chemist, you can think of it with this analogy. Imagine polystyrene units are red paperclips and butadiene are green paperclips. The HIPS would be strings of green paperclips all balled up and floating in a sea of strings of red paperclips.

In contrast, SBS would be strings of mixed red and green paperclips (red and green in each string, or polymer chain)

Chris DeArmitt

"Knowledge has no value except that which can be gained from its application toward some worthwhile end."
Think and Grow Rich - Napoleon Hill

 

[Pud]

A very neat and succinct analogy (yet again)...

Too much time on your hands....

Harry

http://www.tynevalleyplastics.co.uk

 

[patprimmer]

Chris

Very interesting. The standard we have come to expect from you.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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[Demon3]

Thanks guys. Getting such a response from you fellows inspires me!

Chris DeArmitt

"Knowledge has no value except that which can be gained from its application toward some worthwhile end."
Think and Grow Rich - Napoleon Hill