ASTM D7605 Thermoplastic Elastomers-Measurement of Rheological and Dynamic Properties

Scope:

The ASTM D7605 test method is essential for determining the dynamic and viscoelastic properties of polymers and thermoplastic elastomers at specific temperatures. These properties play a crucial role in product processing and its performance evaluation. Moreover, the results obtained are used for quality control, development, and research purposes. This creates a standard for deciding the applications and reliability of these products.

Procedure:

In ASTM D7605, the specimen is kept in a closed cavity at a specific temperature and oscillated. A sinusoidal torque is created due to the sinusoidal strain, which indicates the viscoelastic properties of the specimen. Frequency sweep test, strain sweep test, and temperature sweep test are performed, considering different conditions. The resulting elastic, viscous, shear modulus and viscosity values help determine the rheological properties. 

Video 01: Explanation of a thermoplastic elastomer

Specimen size:

The specimen used in ASTM D7605 testing must be taken as per the requirements. The sample is taken such that it is ±0.02 g of the target mass.  

Data:

The elastic torque S’, viscous torque S”, storage shear modulus G’, loss shear modulus G”, tan δ, complex dynamic viscosity η*, and real dynamic viscosity η’ is determined by performing the test in given conditions. 

Conclusion:

The ASTM D7605 test method is essential for determining the dynamic and viscoelastic properties of polymers and thermoplastic elastomers at specific temperatures.