Sciencemadness Discussion Board

'Polyethylene Glycol 3350 NF'

bfesser - 7-2-2012 at 14:31

I recently underwent a laparoscopic appendectomy and was given a bottle polyethylene glycol (PEG) with an average molecular weight of 3350. After finishing with the prescribed regimen of painkiller and PEG laxative, I have half a bottle (maybe 450 grams) of the PEG remaining. Besides ingestion and combustion, does anyone have a suggestion of something <em>interesting or useful</em> to do with it? A forum search didn't turn up much.

zoombafu - 7-2-2012 at 14:49

I suppose as a sexual lubricant...

AndersHoveland - 7-2-2012 at 15:25

It can be nitrated if you have an interest in "energetics"...

correction: mistake, I was thinking of polyvinyl alcohol

[Edited on 8-2-2012 by AndersHoveland]

UnintentionalChaos - 7-2-2012 at 15:39

Quote: Originally posted by AndersHoveland  
It can be nitrated if you have an interest in "energetics"...


That would do just about nothing, seeing as how the only available sites to add nitro esters are on the ends of the obscenely long chains.

Quote: Originally posted by zoombafu  
I suppose as a sexual lubricant...


Sounds painful, as it's a powder.

I'd treat it as a non-volatile polar solvent for high-temperature reactions.

[Edited on 2-7-12 by UnintentionalChaos]

garage chemist - 8-2-2012 at 00:14

I use PEG 1500 as the medium for my oil bath. It solidifies at room temperature (mp. 44-48°C), so there's no danger of spills when the oil bath is not in use, and most importantly, the solidified PEG is very water soluble so I can simply rinse the flasks with water and they become perfectly clean on the outside. No more greasy mess as with other oils or fats!
The solid PEG1500 is not noticeably hygroscopic, its surface stays dry and waxy.

The principal disadvantages of this otherwise perfect heat carrier are the price (ca. EUR 17 per kg), the high viscosity of the liquid below 100°C (it becomes less viscous when hotter)
and the mediocre stability towards heat and oxygen above 150°C. An antioxidant needs to be added (ideally, phenothiazine or phenyl-alpha-naphthylamine) in order to make the bath stable for prolonged operation above 150°C.
See page 15, right side:
http://www.essentialingredients.com/pdf/PolyglykolsforPerson...
However, someone I know has used this bath in the lab for many months without stabilizer, and the only symptoms were darkening and slow "evaporation" of the liquid. The bath remains useable despite the oxidation and weight loss, and I still think that PEGs are near perfect oil baths for the lab when temperatures are not overly high.

Organikum - 8-2-2012 at 03:53

Phase transfer catalyst in organic reactions, benzylalcohol to benzaldehyde for example, just to name a basic one.

DougTheMapper - 11-2-2012 at 08:39

According to Wikipedia, PEG is an anti-foaming agent used in some foods. Perhaps it could prevent foaming in a reaction? I have a bottle of the same stuff from a colonoscopy a few years back but I've yet to find a use for it either.

Magpie - 24-4-2012 at 13:08

I now have a few hundred grams of polyethylene glycol 3350 sold as a laxative. I'm wondering also how I might put it to a higher use. Here's its formula:

polyethylene glycol.bmp - 89kB

What I would really like to do is depolymerize it down to glyme or diglyme, both expensive, hard-to-find, and useful solvents:

glyme & diglyme.bmp - 157kB

Does anyone know how to do this?


garage chemist - 24-4-2012 at 13:19

I don't think that you can make glyme from this easily. Forming the methyl ether of a primary alcohol is normally done via Williamson synthesis with alkyl halide or dialkyl sulfate.
Glymes are made from ethylene oxide and dimethyl ether, this way the methyl ether bonds are formed via ring opening of the oxirane.

You could try converting it into dioxane. That would be very useful too. Dioxane can be used for coalescence and purification of dirty potassium.
Try distilling some of the PEG slowly over a free flame with a small amount of sulfuric acid added. Do you know how dioxane smells like?

watson.fawkes - 24-4-2012 at 13:23

Quote: Originally posted by Magpie  
I now have a few hundred grams of polyethylene glycol 3350 sold as a laxative. I'm wondering also how I might put it to a higher use.
Hair moisturizer? It's certainly, uh, higher.

Sorry, that was too good a straight line you provided.

Magpie - 24-4-2012 at 14:39

Quote: Originally posted by garage chemist  

Try distilling some of the PEG slowly over a free flame with a small amount of sulfuric acid added. Do you know how dioxane smells like?


I will give this a try. No, I don't think I've ever used dioxane.

UnintentinalChaos has a nice YouTube video showing how he depolymerizes polystyrene. If only it were that simple with PEG.


Quote: Originally posted by watson.fawkes  
Hair moisturizer? It's certainly, uh, higher.

Sorry, that was too good a straight line you provided.


Yes, the poor PEG is surely begging for a use with a little more dignity. ;)

bbartlog - 24-4-2012 at 17:23

You can also catalyze the hydrolysis to dioxane: see US patent 4283339 ...

Morgan - 24-4-2012 at 18:47

Bubbles perhaps.

"J-Lube may be the most important polymer for creating giant bubbles. Less than a gram of this powder can turn a gallon of water and twelve ounces (or less) of dishwashing liquid into a potent giant bubble juice. A 10 oz. bottle of J-Lube powder costs less than $20 (including shipping) and can make hundreds of gallons of bubble juice."
"J-Lube is a powder made up of 25% Polyethylene Glycol (often called PEO since it is also known as polyethylene oxide) which is the active ingredient and 75% sucrose which essentially acts as a dispersant. Its primary commercial use is for aiding veterinarians in the birthing of livestock. It adds valuable self-healing qualities to bubble solutions which enables bubbles to complete themselves and enables bubble-in-bubbles. It also reduces the likelihood that a bubble will tear coming off of the wand. In large quantities, it can make bubbles so self healing that any disturbance of the air will break up a large bubble into smaller bubbles. It is thought to work very well with the cellulose-based compounds like Hydroxypropyl Methylcellulose (HPMC) (see above -- it is found in Surgilube) and' 'Hydroxyethyl Cellulose (HEC) (see above -- it is found in KY-Jelly and its knockoffs). Many bubblers report synergies betwen these compounds so that solutions that include J-Lube and either HPMC or HEC have properties that exceed those of solutions with only of these ingredients."
http://soapbubble.wikia.com/wiki/Ingredients
http://en.wikipedia.org/wiki/Polyethylene_glycol

Big Outdoor Soap Bubbles ~ Recipe & How To Do. Time Warp Discovery Channel Featured Expert
http://www.youtube.com/watch?v=gQmpVIgDvgQ

Keith Michael Johnson explores how bubbles work & what we can do with them. BUBBLEOLOGY
http://www.youtube.com/watch?v=8_5AsgMM4CE&list=UU6WtmFF...