High Performance, Eco-Friendly Filler from Palm Fibre
Aneesa P1, Navadeep Manhas2, K. Balasubramanian3*, Sunil Nimje2
1Centre for Biopolymer Science and Technology (a unit of CIPET), Kerala- 680102
2 Dept.of Mechanical Engineering, DIAT (DU), Ministry of Defence Pune 411 025
3Dept.of Materials Engineering, DIAT (DU), Ministry of Defence Pune 411 025
*Corresponding author: ,
Keywords- Nanofibrils, Palm fibre, Ultrasonication.
ABSTRACT
The surface functionalized cellulose nanofibrils have found commodious applications in various fields such as bio-nanocomposite, tissue engineering scaffolds, and nanodevices owing to their excellent mechanical properties, sustainability and renewable nature. Therefore, the aspiration of the present study is fabrication of competent reinforcing nanofibrils, which have a greater surface area with respect to volume that leads to a superior interaction with matrix system of composite from palm fibres, which is an influential raw material. We have demonstrated an economically viable model for the isolation of nanofibrils from palm fibres employing relatively less harmful and mild chemicals. The design involves chemi-mechanical techniques which comprises of alkali treatment, bleaching and ultrasonication, which are favorable for the cellulose purification and nano fibrillation through delignification and defibrillation.
The alkaline treatment of leaves of palm tree with caustic soda removes lignin, hemicellulose, wax and oil shielding the peripheral surface of the fibre cell wall and depolymerises the native cellulose. Mercerized fibre is then subjected to bleaching with 3%, 5%, 7% and 10% of bleaching solution for eradication of the remnant lignin. 5% bleaching treatment was found to be optimum, as confirmed by FTIR. The structural and morphological characteristics of raw fibre, chemically treated fibre and isolated nanofibres were investigated through FE-SEM, which reveals substantial reduction in diameter of palm fibre to 30nm by a greener method of ultrasonication for 60 min with 145 W power rating and 512 KJ of energy. FTIR spectra have shown partial removal of hemicellulose and lignin. Lignin present in raw palm fibre gives a characteristic peak at 1592cm-1 corresponding to the aromatic skeletal vibration and carbonyl group. This peak was absent in spectra of bleached fibre. These fibres find extensive applications as nanofillers in structural composites for automobiles and medical fields.