Thermomechanical characterization of shape memory polymers

Bilim Atli; Farhan Gandhi; Greg Karst

doi:10.1117/12.715248

Translator Disclaimer

5 April 2007 Thermomechanical characterization of shape memory polymers

Bilim Atli, Farhan Gandhi, Greg Karst

Author Affiliations +

Proceedings Volume 6524, Electroactive Polymer Actuators and Devices (EAPAD) 2007; 65241S (2007) https://doi.org/10.1117/12.715248
Event: SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2007, San Diego, California, United States

Abstract

Data from comprehensive thermomechanical tests of shape memory polymers are reported, with specimens tested up to 75% strain and between 30-120°C temperatures. The data is analyzed and key observations are drawn. The stress/strain behavior during loading at temperatures above glass transition for the Veriflex shape memory polymer tested was linear and did not show much variation with the actual temperature. When the polymer is cooled with end constraints, thermally induced tensile stresses developed, but only after the temperature reduced below glass transition and the material stiffened. When the constraints were then released, 97-98% of the original strain was locked in. Reheating the shape memory polymer beyond the glass transition temperature resulted in shape recovery (shape memory effect). When the polymer was reheated while constraining the strain, the full recovery stress developed was about the stress the polymer was initially loaded to during deformation at high temperature. Examining the Young's modulus at elevated temperature and low temperature showed that Veriflex softened by around 40-60 times when heated through glass transition.

Citation Download Citation

Bilim Atli, Farhan Gandhi, and Greg Karst "Thermomechanical characterization of shape memory polymers", Proc. SPIE 6524, Electroactive Polymer Actuators and Devices (EAPAD) 2007, 65241S (5 April 2007); https://doi.org/10.1117/12.715248

ACCESS THE FULL ARTICLE