Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


vapor pressure of PEG 400

vapor pressure of PEG 400

vapor pressure of PEG 400

Hi, I am trying to find out if there is such a thing as a published vapor pressure for polyethylene glycol 400 at a elevated temperature. SDS's I have found show the vapor pressure is < 0.01 mm Hg psi at 20C. My application is using PEG400 at about 300 F. The problem is that a state regulator is trying to say that there are VOC's being emitted from the PEG400 solution and since they can't find a vapor pressure for PEG400 at elevated temperature, they are assuming ethylene glycol, which is not even close to the same thing as PEG400. I would expect PEG400 to have a much lower vapor pressure than ethylene glycol at 300F. Does anyone know of a resource that either indicates how to estimate a vapor pressure at elevated temperature for PEG400 or supporting documentation that it is very very low, like less than 0.1 psi or something?

-Ryan Birkenholz, Licensed PE in MN and IA

RE: vapor pressure of PEG 400

PEG-400 is MW = 400 (about 8.7 oxyethylene units per molecule). You would be much better off modeling it with the highest MW glycol homolog you can find data on, like di-, tri-, or tetra-ethylene glycol. I know Aspen 7.3 has properties on those. If nobody comes thru with data on PEG-400, and you need data on tetra-EG, let me know.

Good luck,

To a ChE, the glass is always full - 1/2 air and 1/2 water.

RE: vapor pressure of PEG 400

Maybe this doesnt help, but the sat vap pressure of tetraethylene glycol (mol wt 194) is 1.0mmHg at 154degC (from Perry Chem Engg Handbook, 6th edition, pg 3-61), which translates to 0.0193psia at 310degF, so one would expect the sat vap pressure for polyethylene glycol with a mean mol wt of 400 to be even lower at 300degF.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close