Curious George - 7-4-2011 at 12:03
Have a supply of HDPE that is contaminated with an organic peroxide -- probably DTBP = Di-tert-butyl peroxide. This peroxide is typically used as a
cross linking agent. The peroxide has been ABSORBED by the HDPE, but has not been heated yet, so there is no cross linking reaction. I need to
EXTRACT the DTBP from the HDPE to prevent cross linking when the HDPE is melted.
Any suggestions?
Thanks!
HydroCarbon - 7-4-2011 at 15:16
You could possibly try soaking it in a solvent that the peroxide is highly soluble in, and also that swells the polymer. Im thinking methylene
chloride, or chloroform.
Curious George - 8-4-2011 at 08:39
Tried Xylene, and it worked well. Problem is that xylene is too expensive. Is there any way to do this in an AQUEOUS system?
I've tried adding caustic and adding ammonia to water. They have removed "something" from the HDPE (solutions become yellow to brown), but NOT the X
linking peroxide.
Also tried several household detergents, but I'm assuming not enough 'driving force' to move the "plastic soluble" organics from the HDPE to the
aqueous phase.
Any suggestions? I KNOW there are some BRILLIANT people out there !
Eclectic - 8-4-2011 at 08:51
Try kerosene?
chemrox - 8-4-2011 at 09:18
also ethylacetate (slower)- is the reason for extracting it because you want to melt the HDPE? If you heat it will it bond to the HDPE? (2 free rads)
Curious George - 8-4-2011 at 09:29
Kerosene or #2 heating oil are my next two choices. However, I'm afraid that the lack of aromaticity will prevent good extraction. Will report
back...
Yes, I want to MELT the HDPE w/o triggering the crosslinking. As is, it starts to melt and then "sets up" before I can use it. I can either remove
(extract) the XL agent, OR, is there some way to PREVENT IT from working?
Either way, I'd like to do this in AQUEOUS solution (or perhaps an emulsion?) if possible.
Appreciate any advice....
mr.crow - 8-4-2011 at 10:28
Can't you just get new HDPE? Unless you are operating on a large scale of course
HydroCarbon - 8-4-2011 at 13:58
I doubt you'll be able to do it with aqueous, as the solvent (water) won't be able to penetrate the polymer matrix. Heating oil and other low grade
organic materials are also a bad idea as they would contaminate your polymer with the non-volatile contaminants that are present.
One thing you may want to try is grinding the polymer to a fine powder; then you may even be able to extract the peroxide with an aqueous solution, or
at least a low amount of clean solvent.