A comparative study of characterization and water absorption behaviour of polyester composites with inorganic and organic fibers

Abstract

Abstract The research deals with fabrication and characterization of h-BN composites with polyester as the matrix material as well as hybrid composites incorporating inorganic as well as organic filler. The inorganic ceramic filler like h-BN tends to enhance the thermal properties and imparting moisture resistant properties whereas organic fillers like Peanut husk increases the strength and stability of the composites. The implications of embedment of h-BN on the thermal conductivity (keff), mechanical characteristics, and morphological parameters are apprehended. It is observed that increase in filler content increases the effective thermal conductivity. With 35 wt% of h-BN the improvement of keff is appreciably elevated to 23.69%.In case of hybrid composites, the keff value decreases to some extent due to insulative property of peanut husk fibers but shows an improvement in mechanical properties with addition of peanut husk fibers. Therefore, thermal conductivity is compromised a little for achieving a balance between physical, mechanical and thermal properties. Though theoretical Rule of Mixture model aids to be well co-correlation to estimate keff for spherical Boron Nitride particles in composites, a better model is proposed for the same. At about filler volume fractions more than 20%, there is a conductivity jump in the composites because of the interaction between Boron Nitride particles and matrix forming conductive networks and this phenomenon occurs at a volume fraction called the percolation threshold. Hence, with higher thermal conductivity and good mechanical properties with very low water absorption, composites with appropriate amount of particulates can be utilized in various fields like heat engine laminates, engine casings, military equipments, fins and heat sinks, printed circuit board substrates etc. where faster heat transfer is a necessity.