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DMTA Analysis of Polymers

Objective: Measure the dynamic mechanical loss and storage modulus as a function of frequency using time-temperature superposition (TTS) of dynamic mechanical analyzer (DMA) data at various temperatures from a rubbery sample (PDMS or butadiene rubber), a glassy sample (polycarbonate, polystyrene, polyethylene terephthalate (PET) or polymethylmethacrylate) and a semi-crystalline sample (polypropylene or polyethylene).  Investigate the effects of filler on the DMA data and TTS.

Materials:
Rectangular samples of solid polymer:  polydimethylsiloxane (silicone rubber) PDMS or polybutadiene rubber, polycarbonate, polystyrene or polymethylmethacrylate and polytetrafluoro ethylene (PTFE), polypropylene or polyethylene.  We will use the Mettler Toledo DMA 861 in the Characterization Lab.  Nylon thread (glide dental floss) in air and in water at 20 and 40C (see Mettler examples). 

Procedure:

    The Procedure will follow the operating manual for the Mettler-Toledo DMA 861.

Analysis:

     1) Plot the storage modulus, loss modulus, and tan delta at different temperatures and frequencies  
     2) Describe the observed transitions (compare with the examples on the webpage for the instrument)
3) Determine the plateau modulus and the entanglement molecular weight
4) Determine the glassy modulus.
5) Plot a Cole-Cole Plot and determine if the material displays a single relaxation time and other information available from the Cole Cole Plot
6) Perform a time temperature superposition to show the master curve.  

     The analysis follows the operation manual for the Mettler-Toledo DMA 861.

     The report should include TTS plots for each of the polymers studied at different temperatures and different frequencies.

Questions:

    Please answer the quiz questions and either include them in the lab write-up or add them to the end of the report.