Structure and properties of oil palm-based nanocellulose reinforced chitosan nanocomposite for efficient synthesis of butyl butyrate

Abstract

In this study, nanocellulose (NC) was successfully extracted from oil palm frond leaves (OPFL) using a combination of bleaching, alkaline treatment and acid hydrolysis. X-ray diffractogram revealed the extracted NC was crystalline with a crystallinity index of 70.2%. This indicates its suitability as nano-fillers for preparing the chitosan/nanocellulose (CS-NC) supports to immobilize Candida rugosa lipase (CRL) to produce the CRL/CS-NC biocatalysts. FTIR, FESEM and TGA characterizations of the CRL/CS-NC confirm the CRLs were successfully conjugated to the CS-NC supports. The air-dried CS-NC supports gave satisfactory immobilization of the CRLs (5.2 mg/g) with the resultant CRL/CS-NCs catalysed conversions of ≥80% of butyl butyrate within 6 h. Time course reaction profile revealed that 76.3% butyl butyrate conversion was achieved at 4 h immobilization time using 3 mg/mL of CRL/CS-NCs. NMR analyses on the purified butyl butyrate confirmed that the ester was successfully synthesized.