Shape memory effect in thermo-plastic rubber (TPR)
Date of Issue2019-05-05
School of Mechanical and Aerospace Engineering
Shape memory effect (SME) is a quite novel and interesting phenomenon to all kinds of materials, though the working mechanism of SME in different materials may be distinct to each other. Three different mechanisms, consisting of dual-state, dual-component and partial-transition are the main reasons that lead to shape memory effect in almost all metals, ceramics, polymers and composites, whether they work on the materials individually or jointly. Shape memory polymers are favorable materials for ergonomics such as comfort fitting clothes and footwear because of its manual programmability instead of using a heavy machine to do the programming. Therefore, to make use of the shape memory effects, different design and synthesis methodologies are adopted to investigate how well the SME can achieve. In this thesis, a commercially available polymeric material, styrene-butadiene-styrene block copolymer (thermo-plastic rubber, TPR) pellets are manufactured into thin films to thoroughly investigate its mechanical response and shape memory effect. The elasticity and ductility of TPR are considerably good under room temperature, but not the shape memory effect such that the laminate composite is proposed to improve it. Finally, alternative method to fabricate TPR thin film is proposed to eliminate the problem of anisotropy and residual stress. But this method is hazardous to environmental and health such that it is not suitable for mass production.