Hardness and compressive properties of calcium carbonate derived from clam shell filled unsaturated polyester composites

Abstract

The correlations between hardness and compressive strength for different size range of filler have been investigated through experiments. The filler was ground from the shell of local clam known as Polymesoda bengalensis and graded into eight different mean sizes. Hardness and compression tests were done, and the compressive strength values correlated with the Vickers hardness number. The result showed that the hardness of the unsaturated polyester improved as the CaCO₃ filler was infused into the matrix. Great enhancement of compressive modulus was achieved as filler size and filler content increased. For compressive strength, finer particles had shown better value than the courser filler at similar filler loading. The correlation between hardness and compressive strength of all samples was found to be lower than 3.

Keywords:

• Calcium carbonate
• Polymesoda bengalensis
• Vickers hardness number
• Compressive strength
• Unsaturated polyester, Tabor's relation

Acknowledgements

The authors wish to thank University of Malaya for providing financial support and research facilities. This research was financially supported by the Postgraduate Research Grant (PV096/2012A) of University of Malaya, Malaysia.