Physical and mechanical properties of magnetic iron filled rubber composites / Nurul Husna Rajhan

The implementation of base isolators as seismic isolators or laminated rubber bearings is useful for high rise buildings and bridge constructions, especially in seismic prone areas. Generally, a base isolator is made up of alternate layers of steel and rubber. The idea of adopting magnetoreological elastomers (MREs) in base isolator systems was introduced in the past few years in order to improve the efficiency of base isolator systems. As planned, this research's aim is to study the performance of MRE composites due to effect of carbon black loading. The compounding process of MRE development was done using two roll mills and a conventional vulcanization system. The cure assessment of MRE composites was determined by Rheometer 100. The determination of MRE composites performance in this study includes the mechanical test, thermal test and magnetic test. The mechanical test through tensile test, hardness test and rebound test. Then, the morphological characterization was observed using a Scanning Electron Microscopy (SEM). The magnetic properties of MRE composites were evaluated by a Vibrating Sample Magnetometer (VSM). The thermal test involves determination of thermal behaviour of MRE composites using a Thermogravimetric Analyser (TGA), thus the degradation points of MRE composites were examined. Results show that the incorporation of carbon black loading reduces the cure time of MRE composites. The tensile test shows that as carbon black loading increases, the tensile strength also increases until an optimum value before it reduces back. The elongation would increase with carbon black loading. However, if the carbon black loading is increased more than optimum amount, the elongation decreases. The SEM results reveal that the morphology observation of MRE composites strongly proves and enhances the results of tensile strength and magnetization test. The magnetization values of MREs decreases with increasing carbon black loading. Furthermore, the saturation magnetization of MRE composites through VSM starts to occur when magnetization value reaches 0.7 Tesla. The thermal stability of MRE composites increases with increasing carbon black loading. Also, the MRE composites are highly decomposed at temperature in the range of 375°C to 400°C through the degradation process of TGA analysis.