04-28-04 23:19
No 503688
Hi there,
I know there's lot here about making polyphophoric acid so I will wait till TFSE is back, but in the mean time is anyone aware of references about the dehydration/vacuum method?
Thanks,
FF
Be joyful, though you've concided the facts!
(Hive Bee)
04-29-04 01:43
No 503710
The preparation of polyphosphoric acid by heating phosphoric acid under vacuum is described in Organikum in the reagents section. A rough translation:
"The water from the 85% H3PO4 is distilled out under the vacuum of a vater jet pump and the rest is heated for 6 hours at 150°C in the same vacuum. The remaining phosphoric acid crystalises out."
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