Changes in crystallinity of sago palm (Metroxylon sago spp.) waste during cellulose extraction

Abstract

Sago palm (Metroxylon sago spp.) is one of the major agricultural plants in Malaysia. Sago pith waste (SPW), which is left behind after sago starch extraction, is disposed of by washing off into the nearby river. Reuse of SPW provides a solution to the problem of discarding the waste. In this study, cellulose has been extracted from SPW. The fibers were pretreated with 2% of aqueous sodium hydroxide (NaOH) solution before bleaching with an acidified sodium chlorite (NaClO2) and acetate buffer solution. The influence of NaOH and bleaching treatment on the cellulose crystallinity of SPW has been investigated using chemical analysis, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). From XRD analysis, the crystallinity index (CI) was calculated. The CI of SPW increased significantly by 110% after the chemical treatments. The FTIR analysis proved the dissolution of the non-cellulosic components by NaOH and NaClO2 treatments.