Physical Mechanical and Thermal Characterization of Hexagonal Boron Nitride and Sisal Fiber Reinforced Polyester Composites for Microelectronic Applications

Abstract

This thesis presents an experimental study on the physical, mechanical, thermal and dielectric behaviour of polyester-based composites filled with micro-sized hexagonal boron nitride and polyester-based hybrid composite filled with hexagonal boron nitride and short sisal fiber. The objective of the investigation is to explore the possibility of using ceramic filler in combination with a natural fiber in the polymer matrix to develop a hybrid composite suitable for microelectronic applications. The thesis is comprised of three parts. The first part of the thesis described the raw material used for composite preparation along with the method implemented for surface modification of hexagonal boron nitride and short sisal fiber using a suitable chemical reagent. This part of the thesis also had a detailed description of the route adopted for the fabrication of different sets of the composite body. Apart from that, a detailed discussion of the experiments conducted during the research is also discussed in this part of the thesis. The second part of the thesis consists of the results obtained during the physical, mechanical, thermal and dielectric characterisation of polyester filled with a single filler i.e. hexagonal boron nitride. All the properties are evaluated as a function of filler loading. This part of the thesis also discussed the microstructural features of the fabricated samples. Along with that, the effect of the surface modification of the hexagonal boron nitride using a silane coupling agent (and#947;-aminopropyl triethoxysilane) on the different properties under investigation was also discussed in detail. From the experimental investigation, it has been observed that the silanemodified hBN improves the compatibility and adhesion with the matrix as verified by SEM images. The experimental investigation reveals that the addition of hBN in polyester unwillingly raises the density, void content, and water absorption rate. However, the increment is limited with surface-modified hBN.