Thermo-mechanical modeling of shape and non-shape memory polymers

Abstract

Shape memory materials are a special class of material that has an ability to retain their intended shape when the stimuli causing the shape change is reversed. In the current work, we demonstrate that two non-shape memory polymers when mixed can exhibit shape memory effect. Our model is represented by a viscoelastic system consisting of combinations of springs and dashpots, the mechanical properties of which change with temperature. In the current study we take two materials, wax and rubber, and use their mechanical properties to simulate the shape memory cycles. Initially shape memory cycle is applied on rubber and wax separately, and we show that these materials do not exhibit shape memory behavior. When we mix rubber and wax together, the combined system shows shape memory effect. Moreover, the results of simulation for predicting the behavior of viscoelastic model are in agreement with experimental results showing shape memory nature of the model, which is similar to the polyurethane a known shape memory polymer.