SOLID-STATE C-13 NMR AND DIFFUSE-REFLECTANCE MIDINFRARED SPECTROSCOPIC ANALYSIS OF THE EFFECTS OF RETTING ON THE CHEMICAL-COMPOSITION OF KENAF FIBER

Bast ribbons from Tainung 1 (T-1) and Guatemala 45 (G(45)) cultivars o f kenaf (Hibiscus cannabinus) were subjected to a chemical retting pro cess. The resulting changes at the base and tip regions of each cultiv ar were analysed using solid-state C-13 NMR and diffuse reflectance mi d-infrared spectroscopies. Chemical retting was performed by boiling t he substrates in NaOH (70 g litre(-1)) + NaHSO3 (5 g litre(-1)) for 1 h, after which they were neutralised, washed and air dried. This proce ss produced large decreases in the non-cellulosic components, though 2 5% of the phenolic component was left undegraded, and cellulose crysta llinity was increased by similar to 5% over that in unretted samples.