Isolation and characterization of nanocellulose from empty fruit bunch fiber for nanocomposite application

Abstract

Nowadays, the demands for plastics materials are increasing rapidly. Nevertheless, most of these products are non-environmentally friendly and nonbiodegradable. About 60 to 100 million gallons of petroleum are needed to produce plastics every year around the world. Therefore, there has been growing interest in developing bio–based products that can offer favorable environmental advantages. The purpose of this study is to isolate nanocellulose from empty fruit bunch (EFB) fiber and to investigate reinforcing effect of nanocellulose in poly(vinyl alcohol) (PVA)/starch blend films. The optimization of acid hydrolysis conditions for nanocellulose yield with response surface methodology (RSM) was also investigated. Cellulose and nanocellulose fibers were successfully extracted by using alkali treatment and acid hydrolysis, respectively. Subsequently, a series of PVA/starch film with different content of nanocellulose were prepared by solution casting method. The isolated nanocellulose displayed a relatively high crystallinity, which were around 73% that consisted of rod like nanoparticles with the diameter of 4 to 15 nm. Analysis of the RSM result revealed that high nanocellulose yield (83.42%) was obtained when the sulfuric acid concentration, hydrolysis time and reaction temperature were set at 58 wt%, 43 minutes and 35 °C, respectively. PVA/starch films reinforced with nanocellulose fiber possessed significantly improved properties compared to the film without reinforcement. From the results, PVA/starch films with the addition of 5% (v/v) of nanocellulose suspension exhibited the best combination of properties. This nanocomposite was found to have tensile strength about 5.694 MPa and the elongation at break about 481.85%. In addition, this nanocomposite had good water resistance (19.71% ) and biodegradability (47.73%). It can be concluded that the nanocellulose obtained in this study can be an excellent reinforcing material in PVA/starch blend film.