Influence of Thermal History on Nylon

DETA is an effective tool for characterising the influence of thermal history on the molecular structure of a material and, in turn, on molecular relaxation. 

The P-transition is ill defined in the first temperature scan because molecular motion in the as-received sample is restricted by hydrogen bonding caused by the presence of small amounts of water. Evaporation of the water during the first heating cycle makes the P-transition more detectable during the second scan. 

A broad range of test frequencies is important for isolation of different types of molecular relaxations. As demonstrated by this experiment with Nylon, low frequencies are important for characterising the P-transition, whereas high frequencies help in the separation of the a-transition from other complex phenomena that occur at high temperatures. 

DMTA has been used to explore relaxation processes in amorphous and semicrystalline polymers (see Section 8.1.6). 

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