A phenomenological thermodynamic model for the chemo-responsive shape memory effect in polymers based on Flory–Huggins solution theory
Abstract
We present a phenomenological thermodynamic model to study the constitutive relations and working mechanism of the chemo-responsive shape memory effect (SME) in shape memory polymers (SMPs). On the origin of the Hildebrand solubility parameter, Flory–Huggins interaction parameter and relaxation theory, a phenomenological model is proposed to quantitatively identify the factors influencing the chemo-responsive SMPs. After this, a free-energy function is implemented to couple the constitutive relations of the chemical potential and stress as a function of the weight fraction of solvent and stretch, respectively. Furthermore, the simulation of the phenomenological thermodynamic model is compared with the available experimental results and the simulation results of a semi-empirical model reported in the literature for verification.