Epoxy resin from corn leaves (Zea mays)

https://doi.org/10.70228/CBJ2024057

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ABSTRACT

Epoxy is widely used for its superior adhesive and coating properties. It is utilized in fiber-reinforced products and structural engineering repair applications. It consists mainly of bisphenol A and epichlorohydrin (ECH); however, ECH synthesis uses propylene, which produces chlorinated products that pose environmental concerns. This study aimed to produce epoxy resin from corn leaves as an alternative epichlorohydrin source. Glycerol was initially extracted from the corn leaves by grinding the leaves, boiling the extract, and centrifuging the mixture. The extracted glycerol was reacted with hydrochloric and propionic acid for conversion into dichloropropanol. Dichloropropanol was hydrolyzed with 5.07M NaOH to yield epichlorohydrin. The epichlorohydrin was then synthesized with bisphenol A and NaOH to epoxy resin via a two-step dehydrochlorination process. The epoxy resin was tested in triplicate using ASTM D-4142 to evaluate the following: epoxy content, viscosity, color, hydrolyzable chloride, density, nonvolatile content, and acid value. The total percent yield of glycerol from the overall extraction from corn leaves was 2.44%, while the total yield of epichlorohydrin was 52.24%. The results of testing showed that epoxy content produced a sample mean of 247.37 WPE, viscosity with a mean of 210.64 cP, color with a sample mean of 137 PtCo, hydrolyzable chloride with a mean of 7.88 wt%, density of 0.98 g/ml, and acid value of 3.76 mg KOH/g sample. Overall, the results showed that the epoxy content, viscosity, color, density, nonvolatile content, and acid value of the epoxy resin from corn leaves complied with the ASTM standards except for the hydrolyzable chloride.

Keywords: adhesive, glycerol, dichloropropanol, epichlorohydrin, hydrolyzable chloride