Permanganate Treatment Optimization on Tensile Properties and Water Absorption of Kenaf Fiber-Polypropylene Biocomposites

Abstract

Kenaf fiber has been studied for biocomposites reinforcement due to its renewable and carbon neutrality. Meanwhile, polypropylene sheets are easily processed and considered a prospective thermoplastic matrix source for biocomposites. Hence, the combination of both materials is expected to form an attractive biocomposite. This study aimed to optimize permanganate treatment on tensile properties and water absorption of kenaf-reinforced propylene biocomposites. It thermally tested kenaf fibers and PP using differential scanning calorimetry (DSC) before performing compression molding at 185°C and 70 bars using the film stacking method. The kenaf fiber variables were untreated, alkaline pre-treated, and alkaline-permanganate treated to low concentrations of 0.01 to 0.05 wt% of KMnO4. Furthermore, this study conducted Yarn tensile test and Weibull distribution to find a strength variability statistically. Composite tensile and burn tests were performed to obtain tensile strength, constituent materials, and void volume fractions. Composites fractography was implemented to examine the effect of permanganate on composite water uptake behavior using scanning electron microscopy. This study used low concentration in permanganate treatments than several previous studies. The results showed that biocomposites have a tensile strength of 125 MPa, higher than in previous studies that found a value less than 80 MPa. This study has contributed to the green optimization treatment using lower chemical concentrations but with better results on impregnation, interfacial, water absorption, and mechanical properties of kenaf or polypropylene composites.

Experimental investigation on strengthening of Zea mays root fibres for biodegradable composite materials using potassium permanganate treatment

“…In general, the permanganate treatment comes after the alkaline treatment 48 . One of the most efficient techniques used to enhance the binding at the fibre-polymer interface is the permanganate treatment that leads to changes in the macromolecular and crystallographic structure of the fibre composites as well as improved tensile characteristics, superior flexural strength, increased stiffness, and other attributes 4 , 6 , 15 , 40 , 42 , 51 , 56 . Rearrangement of microfibrils is facilitated by the delignification process that occurs during permanganate action; this improves crystallinity 29 , 44 .…”

“…This also serves to increase the physical and chemical coupling between the fibre and the polymer matrix by enhancing the alignment of the fibres, hence boosting fibre strength, and by slightly roughening the surface of the fibre to create micropores, which serve as the sites for interlocking. Furthermore, chemical treatment can lessen the creation of voids and improve the mechanical properties of the fibres [37][38][39][40][41][42] .…”

The Effect Of Potassium Permanganate On Betung Bamboo (Dendrocalamus Asper) Epoxy Fiber Compositesusing Hand Lay Up Method

“…al. have conducted research using KMnO4 on horn banana natural fiber, with the highest tensile test results of 46 MPa with 0.05% KMnO4 content, compared to no tensile strength treatment of 23 MPa [14]. Mohammed et.…”