10-30-02 02:36
No 374316
Gentlemens,
I am organising stuff for my first reduction with LAH in THF. From everything i read, distilling TFH from PVC cement could be dangerous.
So i am left with these options, one option is to buy for a chem supplier, the other is to separate it from this mixture that i found otc:
TETRAHYDROFURAN ~ 80 %
PYROMELLITIC DIANHYDRIDE ~ 10 to 30%
Would distilling the THF from this mess and then drying it with MgSO4 make the solvent usable for the LAH reduction? Are there any precautions that should be taken while distilling and then storring the stuff?
Thanks!
(Hive Bee)
10-30-02 04:48
No 374352
I dont know how to seperate Pyromellitic Dianhydride from THF because it is soluble in it. Since it boils at ~400C then it should be safe to distill this mixture as long as there are no other chemicals. Test for peroxides. Dry THF with Sodium wire/benzophenone, distill under nitrogen atmosphere (if possible) or reduced pressure.
Sink or SWIM
(Hive Bee)
10-30-02 05:10
No 374360
Just a few months ago, I ran accross a 'universal' solvent welding product that listed 100% THF as the only ingredient on the MSDN. When they gave no info on the product other than highly toxic and flamable I knew it had to be worth looking into. They leave out the resins normally added to the material-specific welding solvents, to achieve the best possible bonding between different polymers.
I think I read somewhere that THF had just reciently been upgraded to a higher restriction profile. So if you do find it to still be available, stock up.
Either way, do be careful. THF is nasty, to breath, touch, taste, hell just remembering an hour sealed into a bathroom distilling that shit nearly triggers a gage reflex. And according to credible sources it is even more susceptable than ether in the formation of peroxides which can spontainiously explode. Sunlight, open flame and O2 exposure should be held to an absolute minimum, and don't even think about storing, transferring or using THF in any plastic container other than PTFE. If you were to drop a buick in a vat of THF, I doubt you would have much left except foam a week later.
And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!
(Chief Bee)
10-30-02 20:11
No 374573
Just as a note, the anhydride above is 1,2,4,5-Benzenetetracarboxylic dianhydride.