Anhydride modification of cultivated kenaf bast fibers: Morphological, spectroscopic, and thermal studies

Abstract

Kenaf bast fiber was chemically modified by using propionic and succinic anhydrides. Five retention times were compared: 30, 60, 120, 180, and 240 minutes at 100°C. Confirmation of anhydride modification was established by the weight percent gain (WPG) and was further confirmed by Fourier Transform Infra-Red (FT-IR) spectroscopy. Based on WPG, succinylated fibers exhibited higher WPG than propionylated fibers. The results of WPG for both succinylated and propionylated fibers showed that 180 minutes was an optimum time for modification, yielding the highest WPG. The thermal stability of modified fibers was characterized with Thermal Gravimetric Analysis (TGA). Succinylated fibers showed better thermal stability than propionylated fibers. Anhydride modification also enhanced the fiber smoothness, as demonstrated by Scanning Electron Microscopy (SEM) analysis. Succinylated fibers showed a much smoother surface as compared to propionylated fibers and untreated fibers. Anhydride modification significantly decreased the contact angle of kenaf bast fibers, thus imparting good adhesion characteristics to the fibers.