Processing And Evaluation Of Chemically Treated Kenaf Bast Hibiscus Cannabinus

ABSTRACT The processing and evaluation of chemically retted kenaf bast Hibiscus cannabinus was carried out using sodium hydroxide and sodium sulphite. The bast of the kenaf plant was retted with 5 sodium hydroxide NaOH and 5 sodium sulphite Na2SO3 at 100 oC for 10 mins. The extracted fibres were subjected to bleaching with hydrogen peroxide H2O2. Mercerization process was carried out on the bleached fibres in order to improve the quality of the fibres. The kenaf bast was converted into clean lustrous smooth and soft fibres using the retting bleaching and mercerization processes. The effects of these treatments were further evaluated using a tensile strength machine and a viscometer. It was observed that the samples retted with Na2SO3 and its corresponding bleached fibre had relatively high tensile strength and low viscosity values while those retted with NaOH and its corresponding bleached samples gave lower tensile strength and high viscosity values. The implication of this is that the samples retted with Na2SO3 were slightly affected while those retted with NaOH were affected most. This was attributed to the inefficiency of NaOH in removing the impurities of the fibre completely and as such lead to lower tensile strength and high viscosity while the reverse is the case for Na2SO3 retted and bleached fibres. The corresponding viscosity of mercerized fibre of NaOH retted samples was low whereas that of Na2SO3 was high. From the results obtained it indicates that Na2SO3 is a better retting agent than NaOH.