[Karkzu]

Hi all,

What is difference between Minimum film forming temprature and glass transition temprature (Tg).

İf you answer my question I would be glad

[Arkcon]

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Hi all,

What is difference between Minimum film forming temprature and glass transition temprature (Tg).

These are two different terms.  You can look up the definitions, online or in a book, and know the difference.  There's no way for us to help here -- either you read it, or we read it for you and type it.  That second way isn't something worthwhile for us to do.

If you read the definitions, what questions do you still have?  We might be able to help with where the real problem is.

İf you answer my question I would be glad

[Karkzu]

You are right I'm sorry. I should have written more clearly but my english is not very well.
Anyway, I begin again

I have reserched on the internet and I learned these terms. What I want to know When I buy powder polymer for mortar, I see this terms in Tds (techinical data sheet). For ex: MFFT 0 C for polyvinyl acetat and I cant interpret in this situtation. But Tg 0 C for polyvinil Ac , Tg 25 C for Polyacyrilic acid  in this case I understand this polymer is more flexible than PAA . But I didnt understand  MFFT.

[Karkzu]

according to the this pdf( www.european-coatings.com/content/download/61618/712441/version/.../45179.pdf)
MFFT and Tg are similar but shouldn't.

[P]

But I didnt understand  MFFT.

MFFT  - Minimum Film Forming Temperature  -  it gives you the minimum temperature at which the polymer will form a film without help.

[Karkzu]

Thank you for answer.
What I mean what is film. Is film solid layer build

[P]

What I mean what is film.

A film is just a thin layer of something.  With a paint, you have the wet film and the dry film. If the MFFT of the polymer is too low then you might not get an even well formed film as it dries. Above the MFFT it should film form more readily and easily.   I am sure there is much more to it than that, but the MFFT is a guideline for the operational temperature of the polymer and it's ability to form a film layer at lower temperatures.

[Karkzu]

"MFFT of the polymer is too low then I might not get an even well formed film as it dries."

 I did not understand that. Why so? Can you explain that for me?

Also I want to ask more question. Can you explain the difference between Tg and MFFT.
For ex; will MFFT inform us about polymer flexibility?

Thank you

[P]

The polymer will be more rigid with a lower Tg. The Tg is the temp at which the polymer is flexible - below that it is stiffer and glass like   -   it is a little more complex than that, but that is about it. It is about degrees of freedom of movement of the bonds in the polymer chains.

I do not know why a low MFFT would give a poor film. I thought it was more about what the MINIMUM usable temperature was - but it is probably more complex again. Maybe it dries/film form too easily/quickly at higher temps....  sorry - I do not know, just that it gives a minimum useful operating temperature for the polymer.

[Karkzu]

Thank you so much for everything, you have been very helpful.