Dynamic mechanical analysis: Difference between revisions

Revision as of 18:36, 17 October 2019

Revision as of 16:17, 18 October 2019

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===Measuring glass transition temperature===

One important application of DMA is measurement of the [[Glass transition#Transition temperature Tg|glass transition temperature]] of polymers. Amorphous polymers have different glass transition temperatures, above which the material will have [[rubber]]y properties instead of glassy behavior and the stiffness of the material will drop dramatically with an increase in viscosity. At the glass transition, the storage modulus decreases dramatically and the loss modulus reaches a maximum. Temperature-sweeping DMA is often used to characterize the glass transition temperature of a material.[[File:2019-10-17 20 23 45-DMA Reference Measurements Linear Drive - Anton Paar RheoCompass™.png|alt=|thumb|325x325px|Figure 2. Typical DMA thermogram of an amorphous thermoplastic (polycarbonate). Storage Modulus (E’) and Loss Modulus (E’’) and Loss Factor tan(delta) are plotted as function of temperature. The glass transition temperature of Polycarbonate was detected to be around 151°C (evaluation according to ISO 6721-11)]]

One important application of DMA is measurement of the [[Glass transition#Transition temperature Tg|glass transition temperature]] of polymers. Amorphous polymers have different glass transition temperatures, above which the material will have [[rubber]]y properties instead of glassy behavior and the stiffness of the material will drop dramatically with an increase in viscosity. At the glass transition, the storage modulus decreases dramatically and the loss modulus reaches a maximum. Temperature-sweeping DMA is often used to characterize the glass transition temperature of a material.

===Polymer composition===