MODIFICATION OF PURUN TIKUS (ELEOCHARIS DULCIS) AS A NATURAL FIBER COMPOSITE USING KMnO4 AND NaOH

Abstract

The choice of natural fibers as a composite reinforcing material is related to the advantages of being cheap, abundant, renewable, and environmentally friendly. This research was conducted to study the effect of de-lignification treatment on the properties of purun tikus (Eleocharis Dulcis) fiber. Purun tikus fiber has been modified with the alkaline treatment of KMnO4 2% and NaOH 5%. This treatment was mainly applied to improve the physical and chemical properties of purun tikus fiber. Changes in chemical characteristics (water, lignin, cellulose, and hemicellulose), physical (density), mechanical (tensile strength), morphology, and elemental content of purun tikus before and after treated with alkaline were studied. The measurements showed an increase in water content and density while lignin, cellulose, and hemicellulose were decreased. Thus the alkaline treatment of KMnO4 2% and NaOH 5% reduced lignin, cellulose, and hemicellulose of the purun tikus fiber to reduce the size of the fibers, as shown in SEM measurements. There was a change in elemental content after being treated with KMnO4 2% and NaOH 5%. NaOH treatment was better than KMnO4 treatment in terms of removing lignin and hemicellulose in purun tikus fiber. Although the tensile strength of the purun fibers treated with KMnO4 2% and NaOH 5% were lower than untreated, with less lignin, cellulose, and hemicellulose, it is expected that these fibers will blend better in the composite and improved its mechanical properties.

Modification of Purun Tikus (Eleocharis dulcis) Long Fiber with Potential as Composite Reinforcement Material

“…This is in accordance with the purpose of the treatment, which is to isolate cellulose from lignin and hemicellulose. The hemicellulose content of short fiber purun tikus with 5% NaOH treatment for three hours was 0.97% [3], while in this study, the hemicellulose content of long fiber with the 5% NaOH treatment was 0.33%. This value is smaller than in previous studies.…”

“…Analysis of lignin content showed that the hot water immersion treatment and 5% NaOH treatment had reduced the lignin content of the purun tikus fiber. Haryanti [3] stated that the lignin content in the purun tikus short fiber without treatment was 45.03%. Based on Table 2, both treatments succeeded in reducing the lignin content in the fiber, but the NaOH treatment was the best treatment in reducing the lignin content in the purun tikus fiber.…”

“…This alkaline treatment affects the surface of natural fibers, namely cellulose, which has an optimum water content which can be reduced to obtain natural properties [1,21]. Haryanti [3] obtained lignin content of purun tikus short fiber with 5% NaOH treatment for 3 hours at 13.96%, Sunardi & Istikowati [4] obtained purun tikus lignin content of 26.40%. The lignin content obtained by these two studies was not too large as compared to the lignin content in wood, which ranged from 23-35%.…”

“…Alkalization process has removed impurities in natural fibers, which are lignin and pectin and gave rise to cellulose, thereby increasing the mechanical properties of the fiber [15,23]. Haryanti [3] found that the cellulose content of purun tikus short fiber with the 5% NaOH treatment for three hours was 19.10%. The main advantages of using cellulose as a reinforcing material in polymer matrices are low density, not easily abraded, producing high stiffness properties, easy to recycle, the material is easy to obtain because it is widely available in nature, and cheap [15].…”

“…Purun tikus (Eleocharis dulcis) is a weed that grows in swampy areas that can be used as a constituent of composite materials because it has a fairly high natural fiber content [3]. The province of South Kalimantan has a fairly large availability of natural fiber purun tikus.…”