A Study on the Flammability of Calcium Carbonate-Filled Epoxy Composite

Loke, Wei Xin (2020) A Study on the Flammability of Calcium Carbonate-Filled Epoxy Composite. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

Text Loke Wei Xin.pdf Restricted to Registered users only Download (6MB)

Abstract

In recent years, calcium carbonate (CaCO3) from chicken eggshells (ES) have attracted considerable attention as bio-filler. CaCO3 powder is the cheapest commercially available, and has the additional advantages of low aspect ratio and large surface area. 5, 15, and 25 wt.% CaCO3 filler were incorporated into the epoxy matrix along with addition of 5 wt.% of expandable graphite (EG). The epoxy composite after burning were characterized by scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The effect of CaCO3 filler on the flammability, thermal stability and mechanical performance of the epoxy composites were investigated by UL-94 vertical burning test, TGA, tensile test and impact test respectively. The result obtained from thermogravimetric analysis (TGA) showed that CaCO3 filler improved the thermal stability of epoxy composites by raising the onset decomposition temperature of the epoxy composite. Furthermore, the residue of epoxy composites increased after addition of CaCO3. These char helped slow down burning. EP100 (pure epoxy) exhibits the highest mechanical properties. EP70-ES25-EG05 yields the highest impact value with 1295.59 J/m2, whereas EP90-ES05-EG05 shows the highest tensile properties amongst the epoxy composites. UL-94 vertical burning test revealed that the epoxy composite with 15 and 25 wt.% of filler was able to achieve V-0 rating of and slow down the burning rate to a maximum of 58%. From the findings, CaCO3 derived from chicken eggshell is able to improve thermal stability, possess self-distinguish and fire resisting properties by inhibiting the propagation of flame with the aid of EG. Overall, though the lack of biodegradability of EG may have negative impact on the environment, CaCO3, on the other hand, offer greener benefit, balancing the cost of the material and acting as promising synergist to EG.