as you know, polymers with high Tg (> atmosphere temperature) can not form a thin flexible film to use as sample for DMA. how we can create a thin and not brittle sample of them?
Why do you want to make a thin film and what thickness do you need? If the DMA instrument has different testing apparatus you can test your thick specimens (up to 4, 5 mm) too, in bending or cantilever (single or double) mode. Please specify your polymer. Your argument is not correct. Polymers with high Tg CAN form thin films such as polyimides and other high performance polymers if you properly dissolve them and evaporate solvent slowly. Brittleness is another issue.
Ali Durmus it's a pure acrylic polymer with tg>30 c, and we can just use thickness between 1 micron to 1 mm. when the sample was dried in air, it was broken apart!
Dear Aida,
Firstly, to avoid some confusion and for more clarity, I would like to precise that many polymers with high glass temperature (e.g., about/above 100°C such as PS, PMMA, PC, and so on, are characterized by DMA as thin films (less than 1 mm) or as thick specimens (thickness higher than 1 mm) using adequate methods and DMA devices (Film tension clamps, Dual cantilever clamps, others).
For more information I will recommend to go directly on the web site of TA Instruments or of METTLER TOLEDO, some traditional suppliers of DMA instruments.
In your case, using a specific acrylate (co)polymer, I believe that is firstly a problem of processing to obtain the good specimens for DMA characterization (films or specimens of 1 mm thickness), thus I assume that this aspect need carefully consideration from your part.
However, if your samples are very rigid, to avoid their broken during testing, you can take in consideration the possibility to test thicker specimens…
Good luck in your R&D work,
Marius
I just would like to take your attention on another point; if your sample is very brittle and broken during testing, you can also decrease the frequency or displacement (like 5 micron) in your procedure.
You will definitely see lots of colored graphs, device photographs on the web sites but I am not sure whether you can find operational details about sample preparation and testing conditions on these sites. In my opinion, it is more related to experience and technical communication with the instrument.
dear all
I used a silicon mold to make a thick sheet of that polymer, but after a while, it started to crack and broke apart! besides, the thickness of polymer was not homogeneous. what should I do?
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