The DMTA Analyzers

Analyzers are available for both strain (displacement) and stress (force) control. On the one hand, under strain control, the probe is displaced and the resulting stress of the sample is measured by implementing a force balance transducer, which utilizes different shafts. The advantages of strain control include a better short-term response for materials of low viscosity, which allows experiments of stress relaxation to be performed with relative ease. On the other hand, under stress control a set force is applied while several other experimental conditions (temperature, frequency, or time) are varied. Although stress control analyses are 

7 Dynamic Mechanical Thermai Analysis (DMTA) 1367 PERPFNDrCUUAR i PARALLEL PLANES 

Depending on the commercial trademark, the DMTA analyzers can offer different ranges of temperature and frequency ranges. In general terms, currently available analyzers have can perform between —150 and 600 °C, in multifrequency 

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At temperatures just below melting, the material will start to flow in a liquid-like manner, causing a dramatic reduction in the moduli. Thus, it is advisable to design experiments in the correct fashion by defining a final temperature that is safe enough to avoid spreading and to prevent the polymer blend from sticking to the probe of the DMTA analyzer. 

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