TY - GEN
T1 - Thermomechanical characterization of environmentally conditioned shape memory polymer using nanoindentation
AU - Fulcher, J. T.
AU - Lu, Y. C.
AU - Tandon, G. P.
AU - Foster, D. C.
PY - 2010
Y1 - 2010
N2 - Shape memory polymers (SMPs) are an emerging class of active polymers that have dual-shape capability, and are therefore candidate materials for multifunctional reconfigurable structures (i.e., morphing structures). However, the SMPs have not been fully tested to work in relevant environments (variable activation temperature, fuel and water swell, UV radiation, etc.) required for Air Force missions. In this study, epoxy-based SMPs were conditioned separately in simulated service environments designed to be reflective of anticipated performance requirements, namely, (1) exposure to UV radiation for 125 cycles, (2) immersion in jet-oil at ambient temperature, (3) immersion in jet-oil at 49°C, and (4) immersion in water at 49°C. The novel high-temperature indentation method was used to evaluate the mechanical properties and shape recovery ability of the conditioned SMPs. Results show that environmentally conditioned SMPs exhibit higher moduli in comparison to an unconditioned one. During free recovery, the indentation impressions of all SMPs disappeared as temperature reached above Tg, indicating that the material's ability to regain shape remains relatively unchanged with conditioning.
AB - Shape memory polymers (SMPs) are an emerging class of active polymers that have dual-shape capability, and are therefore candidate materials for multifunctional reconfigurable structures (i.e., morphing structures). However, the SMPs have not been fully tested to work in relevant environments (variable activation temperature, fuel and water swell, UV radiation, etc.) required for Air Force missions. In this study, epoxy-based SMPs were conditioned separately in simulated service environments designed to be reflective of anticipated performance requirements, namely, (1) exposure to UV radiation for 125 cycles, (2) immersion in jet-oil at ambient temperature, (3) immersion in jet-oil at 49°C, and (4) immersion in water at 49°C. The novel high-temperature indentation method was used to evaluate the mechanical properties and shape recovery ability of the conditioned SMPs. Results show that environmentally conditioned SMPs exhibit higher moduli in comparison to an unconditioned one. During free recovery, the indentation impressions of all SMPs disappeared as temperature reached above Tg, indicating that the material's ability to regain shape remains relatively unchanged with conditioning.
KW - Environmental conditioning
KW - Nanoindentation
KW - Shape memory polymer
UR - http://www.scopus.com/inward/record.url?scp=77953528747&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77953528747&partnerID=8YFLogxK
U2 - 10.1117/12.846974
DO - 10.1117/12.846974
M3 - Conference contribution
AN - SCOPUS:77953528747
SN - 9780819480590
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Behavior and Mechanics of Multifunctional Materials and Composites 2010
T2 - Behavior and Mechanics of Multifunctional Materials and Composites 2010
Y2 - 8 March 2010 through 11 March 2010
ER -