I need to calculate tan delta for a polymer sample (thin membrane of thickness 0.05mm), which is deformed at a particular strain and also ramped from room temperature to 300 C. To get a graph tan delta vs. temperature what will be the correct procedure? To do this experiment is frequency is necessary?
I'm not familiar wit hte DMA Q 800 but in general you should just set your measurement parameters (i guess tensile test):
static strain as desired (if strain control is possible)
suitable dynamic strain for your sample and the involved sensors. Here it is important to get a measurable dynamic force (especially for thin samples) in combination with a sufficiently large amplitude (depending on the sensor). For DMA the dynamic amplitude should be small namely within the linear elastic region. Depending on your sample it can be difficult to get suitable parameters if the sample shows transitions and therefore the material properties (modulus) changes. Sometimes it is necessary to perform pretest to get the measurement conditions right.
Your question about the frequency is somewhat ambiguous. Of course you need a frequency for your dynamic deformation (that is the whole point about DMA). Typicall values are 1Hz or 10Hz. But it is also common to measure multiple frequencies. This helps to characterize occuring transitions (their frequency dependence) in you material. For further reading you can check e.g. for WLF behaviour of glass transition or e.g. arrhenius type behaviour for other relaxations. But this really depends on the investigated material. Often Polymers are investigated where the given examples apply.
THe heating rate should be not to high. Typical values are 1 or 2 K/min. It is important that the sample temperature can follow the change in temperature in the oven.
I hope this answer is usefull!
Regards
Matthias
I think some frequency should be given in method for any test in DMA. You can try 1Hz or 10Hz. Take 3 or 4 degree for minut ramp. It will automatically gives storage modulus, loss modulus along with Tan delta.
Thank you for everyone for answering. Actually I have chosen DMA multifrequency constant strain temperature ramp mode; in which I have given 1% strain, various frequencies (I have tried very low to high frequency, single frequency, log, linear, discrete respectively for each trail), temperature ramp 3 degree per minute. The moment after giving all these parameters I am facing an error showing SAMPLE IS YIELDED at 1.9mm. So further I cannot proceed.
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