A mechanical and dielectric study on calcium hydroxide pre-treated kapok husk-reinforced epoxy composites

The present work is aimed to develop and study kapok husk-reinforced epoxy composite for its potential application and focus on the characterization of both kapok husk and its reinforced composite. Kapok husk (KH) has the inherent ability to absorb water, which reduces the durability and strength of the end-use product. So, in order to make the KH filler compatible with hydrophobic epoxy resin, two different treatment (chemical/physical) methods are studied. In the chemical treatment method, the alkalization process using calcium hydroxide, while in the physical treatment method, microwave irradiation has been adopted. Structural characterization of kapok husk has been carried out using X-ray diffractometry (XRD), Fourier transmission infrared (FTIR) spectroscopy, and scanning electron spectroscopy (SEM). The degree of crystallinity is higher in the treated fillers, which are evident from XRD and ascribe to the reorientation of the polymer chain. The cellulose structure of microwave-treated fillers remains nearly same where the chemical treatment alters the structure described by FTIR spectra. SEM data provide the images of surface roughness, micropores and swelling in the case of treated fillers. The composite mechanical characterization has been carried out by INSTRON Universal Testing Machine, where it reveals the microwave-treated filler shows relatively better mechanical properties than other filler categories. The dielectric characterization of composites has been done by LCR meter, where the chemical and microwave-treated filler are observed to have higher and lower dielectric constant, respectively.

Automated summary

The study aims to develop and investigate kapok husk-reinforced epoxy composite, focusing on characterizing both the kapok husk and its reinforced composite. Different treatment methods (chemical/physical) were studied to make the kapok husk filler compatible with hydrophobic epoxy resin. The structural characterization of kapok husk revealed higher crystallinity in the treated fillers, with microwave-treated fillers showing better mechanical properties in composite testing. The dielectric characterization showed that chemical and microwave-treated fillers had higher and lower dielectric constants, respectively.