KESUM (POLYGONUM MINUS) FIBER BIOCOMPOSITE: EFFECT OF ALKALI TREATMENT ON THE TENSILE, MORPHOLOGICAL AND THERMAL PROPERTIES

Abstract

In Malaysia, Polygonum minus (Polygonaceae), often known as 'kesum,' is one of the most widely used food additives, flavoring agents, and traditional pain relievers. The primary purpose of this study is to compare the interfacial adhesion qualities of untreated Kesum fiber with alkali-treated Kesum fiber impregnated in Polylactic Acid (PLA) for PLA/Kesum biocomposite active packaging and manufacture utilizing the Solution Casting technique. The mechanical, morphological, and thermal properties of the bio-composite have been compared to those of PLA. Good interfacial bonding between fiber and matrix increases the tensile properties of composite material by increasing the frictional resistance against tensile loading in alkali-treated samples, as indicated by the mechanical properties. A SEM image demonstrated that PLA with alkali-treated Kesum exhibits enhanced stress transmission between the matrix and fibers. The mechanical properties of PLA/Kesum bio-composites will be enhanced by a good stress transfer of fiber-matrix due to a better fiber-matrix adhesion. In addition to the good miscibility of PLA with untreated kesum fiber, thermal investigations conducted on these samples demonstrate the superior thermal stability of PLA with alkali-treated Kesum at a higher decomposition temperature.