Characterization of silicone-carbon black polymer composites

• Main Author: Teo, Jun Wei.
• Other Authors: Huang Weimin
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Material testing and characterization; DRNTU::Engineering::Materials::Composite materials
• Online Access: http://hdl.handle.net/10356/16235
• Institution: Nanyang Technological University

The fascinating functionality and applications of shape-memory polymers (SMPs) has attracted significant interest from both industrial and academic researchers. Shape memory materials are stimuli-responsive, and possess the ability to “memorize” a macroscopic (permanent) shape, be manipulated and “fixed” to a temporary and dormant shape under specific conditions of temperature and stress. A thermal, electrical, or environmental command will be required for SMPs to return to its original, stress free condition. Experimental studies were conducted to investigate the possible alignment of nano-sized carbon black particles in a polymer matrix when subjected to a range of excitation frequency, as well as the electrical conductivity of the polymer samples when subjected to different volume fractions of carbon black powder. The project was divided into 4 main sections, namely performing literature review, design of the adaptor, fabrication of the SMP samples, and to carry out resistivity testing on the samples. Experimental data obtained from resistivity testing has proved that there was significant improvement in the conductivity of CB polymers was in the direction transverse to the direction of vibration. The improvements in resistivity for the 8% and 10% samples at an excitation frequency of 150 Hz as compared to similar samples that did not underwent vibration were 18.93% and 30.55% respectively. Therefore, although the Standing Wave Theory is not totally applicable in viscous mediums, it can be conjectured that partial alignment of nano-sized CB chains can still be formed within the polymer matrix in the transverse direction. Experimental data also exemplify the improvement of electrical conductivity in the direction parallel to the direction of vibration. The improvements in resistivity for the 8% and 10% samples at an excitation frequency of 150 Hz as compared to similar samples that did not underwent vibration were 7.07% and 12.24% respectively.