Viscoelasticity of Shape Memory Polymer: Polyurethane series DiARY

Abstract

This study examined the creep behavior of DiARY ® , a shape-memory polymer (SMP), and the factors influencing the creep behavior. The creep test using the short term method obtained the master curve for the creep compliance, and confirmed the time-temperature superposition principle. Using this method, physical aging has little effect on the results of the creep test. To examine the effects of physical aging, we performed the creep test without using this method, which showed that physical aging alters the energy of activation of DiARY and the time-physical age time dependency at a specific temperature. The aging master curves were obtained as very smooth curves. In addition, the aging shift factors were attained when creating the aging master curves. The effect of physical aging depended on the time and temperature, confirming the time-physical aging time superposition principle, and achieved the effect of physical aging described as the aging shift rate. Using the master curve, time-temperature shift factor, and aging shift rate, it was possible to estimate the creep deformation, including the effect of physical aging on creep behavior.

Estimating the creep behavior of glass-fiber-reinforced polyamide considering the effects of crystallinity and fiber volume fraction

“…Effect of crystallinity on the creep behavior of PA and GFRPA Previous studies Sakai and Somiya (2006, 2009, Sakai et al (2007Sakai et al ( , 2011aSakai et al ( , 2011bSakai et al ( , 2015 and Tanks et al (2016) have detailed creep behavior as a function of time, temperature, fiber volume fraction, physical aging, and crystallinity. These reports discussed the application of the TTSP and proposed a master curve of creep compliance showing the effect of each influencing variable.…”

“…In previous studies, Sakai and Somiya (2006, 2009, Sakai et al (2007Sakai et al ( , 2011aSakai et al ( , 2011bSakai et al ( , 2015 and Tanks et al (2016) investigated the relationships between creep behavior, crystallinity, and the fiber volume fraction of a variety of polymers. The effects of these variables are described by shift factors that can be used to generate time-temperature curves at any given percent crystallinity or fiber volume fraction.…”

Effect of reinforcing layer on shape fixity and time-dependent deployment in shape-memory polymer textile composites

“…In addition, H TR (t) and a TR (T) were derived using the following methods. In the previous study [29,39], a shift factor was derived from the Williams-LandelFerry (WLF) equation or the Arrhenius equation. However, the WLF equation has poor accuracy below T g [30].…”

Analysis of Isothermal Physical Aging of Polycarbonate from Tensile Creep Tests

“…Barbero et al [15] developed a low-cost, short-term testing procedure to predict the time dependent properties of polymer liners over the lifetime of the installation. Sakai et al [16] studied the creep behavior of a viscoelastic shape memory alloy using Physical aging. Short term creep tests were used to obtain the master curve for the creep compliance, and the time-temperature superposition principle was confirmed.…”