fluorescence
Hazard to Others
Posts: 285
Registered: 11-11-2013
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Gel permeation chromatography of Copolymers ?
Hey Guys,
So I need to perfrom a Gel permeation chromatography tomorrow of a co-polymer (styrene/isoprene-block copolymer) we made a few weeks ago).
Unfortunately I have never worked with that before and the texts they gave us do not mention how Co-Polymers should appear in the Diagram later.
As there are several dozen questions I need to find somewhere for tomorrow I don't have that much time to search more for it.
I assume for a perfect block-copolymer you won't see any difference.l It just seperates the polymers and not the blocks so they would probably still
appear with their normal masses and not seperate into blocks or anything. But I assume if you used two detectors where one scans using UV only the
benzene ring would respond to it and therefore you can see differences and perhaps even the composition.
But for a normal one-detector setup which uses something like a constant scan for refractions, am I able to see any difference between a polymer and a
block-copolymer (besides shifts in masses of course) ?
Thank you all in advance, I googled for a while but couldn't find a good answer on the problem.
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DrP
National Hazard
Posts: 625
Registered: 28-9-2005
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Mood: exothermic
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I am not sure, but I have used GPC for copolymers (statistical rather than block) - I do not think it matters as long as it dissolves readily into
the solvent. I think that all of the GPC's measurements are comparative to whatever calibration standards you use anyway (probably polystyrene), so
all results are approximate comparisons to the standard rather than direct measurements. I think that is the case - it was about 20 years ago anyway.
I hope that helps - sorry if I have misunderstood what you are asking for. If you need any further info then I am not sure I can be of further use,
I'm just saying that I 'think' you should be able to just fire it through your column and get a result.... how accurate will depend on the
calibration standard and the extent of the deviation of your block co-polymer to the standard.
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