RE: ORGLIST: Polyethylene oxide polymerization

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From: will jones (willjones46$##$hotmail.com)
Date: Fri Apr 21 2006 - 10:04:28 EDT

You could probably carry out some more polymerisation with epoxide in the
presence of 2M NaOH solution.

naturally you'll get a range of molecular weights, so then you want to
select the one you want. You can do this combining two different ways:

easiest is size exclusion chromatography. For a molecular weight of 10kDa,
use sephadex G25 or G50. If you want to be able to isolate just the PEO,
then use ammonium acetate as your salt.

Alternatively you can use size selective precipitation. I've used this for
other hydrophilic polymers, so you could give it a go. In my case, my
polymer was soluble in water, insoluble in ethanol. so, as you add ethanol,
the solution goes cloudy. Centrifuge and take off the supernatant. Add more
ethanol, it goes cloudy again and you do the same thing. the larger the
polymer, the more insoluble it is in ethanol (in my case, you may need to
find something else).

But, I'm sure it would still be quicker just to buy some 10kDa PEO.

If you need to make it yourself in large quantities, then size selective
precipitation is the easiest; but not as accurate as using size exclusion
chromatography.

cheers

Will

>From: "Prof. Dr. Hamilton Viana" <hmviana$##$uol.com.br>
>To: everybody$##$orglist.net
>Subject: ORGLIST: Polyethylene oxide polymerization
>Date: Fri, 21 Apr 2006 10:49:11 -0300
>
>Dear ALL!
>
>I got some polyethylene oxide (PEO) with 9000 g/mol as molecular weight but
>I need it with 50000 g/mol.
>Does anybody can suggest me some way to polymerize the former PEO? I mean,
>catalyzer, temperatures, any tip?
>
>TIA !
>
>Dr. Hamilton Viana

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