Constitutive model for epoxy shape memory polymer with regulable phase transition temperature

Abstract

The epoxy shape memory polymer (SMP) with adjustable phase transition temperature is a kind of high-performance shape memory polymer, which can change its phase transition temperature and improve its mechanical properties through the process of photo curing. An epoxy SMP constitutive model combining phase transition and viscoelasticity is established by discretizing the epoxy SMP into several glass phase units and rubbery phase units in this paper. The model includes the viscoelastic constitutive equations of glass phase units and rubber phase units, the parameter expression during shape memory process, and material parameter equation during photocuring process. And the stress relaxation behavior of epoxy SMP at different temperatures and the change of material parameters during the photo-curing process are simulated numerically, and the simulation results perform consistency with the experimental data. The model can not only relate shape memory effect and phase transformation in physics but also better characterize the viscoelastic properties of SMP and predict the shape memory response of SMP.

Design of variable stiffness fixture for computerized embroidery machine based on shape memory polymer

“…At the same time, its elastic modulus at 20°C is taken as the elastic modulus of the glassy phase. p and k are 0.9 and −0.2, respectively, reported in the literature (Zhao et al, 2021). Figure 4 shows the verification of the model through experiments.…”

“…The constitutive model of SMP can provide a reference in the application design of SMP (Fan et al, 2020; Yarali et al, 2020). A constitutive model of epoxy SMP (Zhao et al, 2021), which parameters are easy to obtain and suitable for engineering applications, is employed to reference the distinctive design of SMP’s elastic modulus. It is assumed that the interior of SMP is composed of multiple glassy phase units and rubbery phase units, and the elastic modulus of SMP is described as…”

Dynamic Response and Deformative Mechanism of the Shape Memory Polymer Filled with Low-Melting-Point Alloy under Different Dynamic Loads

“…Due to being convenient to control the temperature, the heat-induced shape memory materials have attracted lots of interest. Lots of work has been performed on the design and fabrication of the heat-induced SMPs, and different types of heat-induced SMPs materials have been developed, including one-way [ 16 , 17 , 18 ], two-way [ 19 , 20 , 21 ], and multiple [ 21 , 22 ] SMPs materials.…”

Design and Synthesis of Shape Memory Phenol-Formaldehyde with Good Irradiation Resistance, Thermal, and Mechanical Properties

“…The temporary shape can be maintained for a long time by cooling down below T trans and then the permanent shape can be automatically recovered upon reheating above T trans . Recently, SMPs and their composites have been applied in many fields including aerospace, − biomedicine, textiles, − and electron devices. − So far, SMPs including polyurethane (PU), − cyanate, , epoxy, − polylactic acid, polyimide, , polyaryletherketone, and rubber , have been reported. However, the study of shape memory phenol-formaldehyde (SMPF) resin is rarely reported. , …”