POTENTIALITY OF Theobroma cacao PEELS EXTRACT AS ADDITIVE ON WATER-BASED PAINT TO HYDROPHOBIC PROPERTIES
RASAYAN Journal of Chemistry
Cacao fruit consists of three major components: fruit, placenta and content. Cacao peels or commonly called as cacao pod/peel is waste with the largest proportion produced by cacao crops which have not been utilized sufficiently. The peel of cacao contains polyphenol compounds, one of which is tannin. It is an antinutrient compound that reduces the quality of materials by forming complex bonds with proteins. Tannin-protein complexes are occurred because of the hydrogen bonding, hydrophobic
... g, hydrophobic interactions, and covalent bonds between the compounds. Here, at this research, with the hydrophobic interaction in tannin, cacao peels extract is mixed as an additive in the water-based paint with concentration variations of 1%, 3%, 5%, 7% and 10%, in order to increase the contact angle so that the paint is hydrophobic. Characterization was performed in accordance with Indonesian National Standardization 3546:2009 emulsion wall paint such as pH and density measurement, accelerated weather resistance, and alkaline resistance. Moreover, the contact angles and its surface morphology then were analyzed from the test results. It turned out that the water-based paint was hydrophobic on the addition of a 3% concentration additive with 127.89 o of contact angle before heating, and 127.26 o after warming in an accelerated weather resistance test. Hence, it was determined that cacao peels extract can improve the hydrophobic properties in water-based paint.