Experimenatal study of pre-strain on the shape memory effect in ethylene vinyl acetate (EVA), polystrene(PS) & polymethyl methacrylate(PMMA)

• Main Author: Peh, Khian Huat.
• Other Authors: Huang Weimin
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/54130
• Institution: Nanyang Technological University

Shape memory polymers have the ability to recover to its original shape even when its physical appearance undergoes significant and seemingly plastic deformation (i.e. Indention Mark) with the presence of the right stimulus such as heat (Thermo-responsive) and etc. In this report, the shape memory effect/ shape recovery of Polymethyl Methacrylate (PMMA), Polystyrene (PS) and Ehylene-vinyl acetate (EVA) are investigated during the 1st 2 trial tests. A further 3rd trial test was conducted on EVA to study the shape recovery by using the Taylor Scanning Machine (Talyscan), which gives a better understanding on the degree of recovery at the same point during different heating temperatures. In addition, a sample (with indentation) EVA was gold coated and subsequently heated to 80ºC (Tg + 25ºC) to understand the effects it has on the surface during the recovery process by using the OLYMPUS SZX7 Stereo Microscope. The results from this study not only reaffirm the shape memory properties that these polymers possess as well as a better understanding of the effects it has on the surface after recovery. Therefore, these SMMs may well be a promising candidate for a broad spectrum of applications, especially in the biomedical industry.