EFFECTS OF EGGSHELL ON THE MICROSTRUCTURES AND PROPERTIES OF PURPLE SWEET POTATOES EGGSHELL BIOCOMPOSITE

ABSTRACT \nThe eggshell as a filler for the matrix is a potential source to improve the \nproperties of biocomposite. The renewable and biodegradable of biocomposite \nmake this material very safe for the environment. \nThe purple sweet potatoes are new material as the matrix of biocomposite. \nThe addition of eggshell as a filler 0 %, 1 %, 2 %, and 3 % is used to improve the \nproperties of biocomposite. \nIncreasing of eggshell powder improves the mechanical properties of \nbiocomposite such as tensile strength and stiffness. The maximum tensile strength \nis 12.80 MPa in 1 % addition of eggshell powder. While the tensile strength of \npurple sweet potatoes is 5.77 MPa. The addition of 2 % and 3 % eggshell powder \nreduce the tensile strength of biocomposite. The tensile strength of PSP ES 2 % \nand 3 % are 4.88 MPa and 5.41 MPa respectively, but the elasticity and \nmodulus elasticity are lower. \nThe agglomeration and pores that are observed on scanning electron \nmicroscope (SEM) lead to low adhesion of filler-matrix and reduction of tensile \nstrength. These also make the water absorption of biocomposite increase due to \nthe easiness of water to absorb by PSP ES biocomposite. It is shown by the \nincreasing of hydrogen bonding of PSP ES biocomposite on FTIR analysis. \nKeywords: biocomposite, purple sweet potatoes, eggshell, tensile strength, \nscanning electron microscope (SEM), FTIR, and water absorption.