Electrical conductivity and thermo-mechanical properties of a polyurethane shape memory polymer filled with aligned micro-sized Ni powders

• Main Author: Quan, Yuan.
• Other Authors: Huang Weimin
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/18195
• Institution: Nanyang Technological University

Shape Memory Polymer (SMP) is a kind of polymer material which can recover from a deformed shape to their original one by applying an external stimulus. SMPs have great potential applications due to their unique properties including light weight, high energy dissipation, uniform composition and low cost. Recently great attention has been paid to enhance the performance of SMPs because of the potential applications for medical and other industrial fields. The purpose of this project is to fabricate SMP thin films with conductive chains inside and investigate the thermo-electro-mechanical properties of these films. SMP thin films with anisotropic thermo-electro-mechanical properties filled with different amounts of nickel (Ni) powders were fabricated at the first time. The Ni particles were linked to horizontal chain direction inside the samples while applying a magnetic field (chained sample) and not (random sample) to study their special thermal and electrical properties. Optical microscope (OM) and scanning electron microscope (SEM) images were introduced to observe the chain-like structures in chained samples. Differential scanning calorimetery (DSC) tests were carried out on the chained samples to determine the relationship between heat flow and the temperature. Dynamic mechanical analysis (DMA) tests were conducted on both random samples and chained samples to determine the variation of the storage modulus against temperature resistivity measurements. The volumetric electrical resistance of random and chained samples was also measured by a multimeter. Results showed that the formation of well-aligned Ni chains (0.5%) apparently increased the electrical conduction of SMP/CB and SMP/CB/Ni composites and presented favorable shape memory effect. The electrical conductivity of SMPs composites along the chain direction can be obviously improved by forming conductive Ni chains under a weak static magnetic field.