Hi, can I know how to change solvent used in my standard stock solution? For your information, I initially prepared the standard (styrene) in methanol and I need to change it to hexane. Can I reused my standard in methanol and reconstitute it with hexane ?
Your question is not an easy one "as it may seem to be".
If the standard stock solution you prepared is large in amount, then you may apply simple vacuum distillation to separate methanol (Tb = ~64.5 oC) from styrene (Tb= ~ 145 oC). Avoid excessive heating (since application of vacuum reduces heat requirements & styrene is susceptible to undesirable polymerization by heat "thermal polymerization").
My advice is to prepare a standard stock solution of styrene in toluene "unless you have to prepare it in hexane". This is what my students used to do when I taught practical polymer chemistry long time ago at Bradford University (Great Britain).
Styrene & toluene are completely miscible. If you would like to go on into polymerizing styrene by the free radical method, you can be sure that polymerization will proceed smoothly with nearly no chain transfer. Polystyrene is soluble in toluene so excess methanol is added to the polymeric solution with vigorous stirring to cause precipitation of the polymer.
Thank you very much Dr. Nizar Matar, I will consider your suggestion. I need to use hexane because I will use GC-MS for styrene analysis. I try to avoid drying up the hexane because styrene is a volatile compound.
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