MD. SHAMSUL ALAM
Department of Applied Chemistry and Chemical Technology, Islamic University, Kushtia, Bangladesh
G. M. ARIFUZZAMAN KHAN
Department of Applied Chemistry and Chemical Technology, Islamic University, Kushtia, Bangladesh
S. M. ABDUR RAZZAQUE
Department of Applied Chemistry and Chemical Technology, Islamic University, Kushtia, Bangladesh
Chemical composition analysis, Dyeing behavior, Oxidative degradation, Pineapple leaf fiber, Tensile strength, Viscosity, Average molecular weight
Resource Development and Management
In the present investigation, efforts have been exerted for an estimation of the constituents of pineapple leaf fiber and to study the degradation behavior, as well as its various physicochemical properties.
Isolation and Estimation of Main Constituents The main constituents of PALF were isolated according to standard method (TAPPI Standard; Abou-Zeid et al. 1984). After treatment of raw PALF with boiling distilled water for 2 h, deaqueoused fibers were obtained. The loss of weight gives the amount of aqueous extracts.
The raw PALF was immersed in a benzene-alcohol mixture (2:1 by volume) for 10 h, maintaining the fiber-liquor ratio at 1:100. The fiber was washed with fresh benzene-alcohol mixture, and finally with alcohol. The loss in weight gives the amount of fatty and waxy matters in PALF. To determine the amount of pectic matters, the dewaxed fiber was heated with 0.5% ammonium oxalate solution at 70–80ºC for 3 days (fiber liquor ratio 1:100) in a heating mantle. The fiber was filtered and washed thoroughly with hot distilled water. The loss in weight gives the amount of pectic matters in PALF. The dewaxed and depectinized fiber was dried at 105ºC and treated with 72% H2SO4 in a ratio of 1 gm fiber per 15 mL of solution with frequently stirring at ordinary temperature. The mixture was allowed to keep for 2 h and then diluted to 3% acid concentration. After refluxing the mixture for 4 h, it was allowed to stand for overnight and filtered through a sintered glass funnel and washed thoroughly with hot distilled water. The constant weight of the residue is the amount of the lignin content of PALF, and this fiber is called delignified fiber. The dewaxed and depectinized fibers were heated with 0.7% NaClO2 solution and buffered to pH 4, at 90–95ºC for 90 min, maintaining the fiber liquor ratio at 1:80. To reduce chlorite action, the fiber was treated with 0.2% sodium metabisulphite solution for 15 min and then washed thoroughly with distilled water. The fiber treated with sodium chlorite is called, chlorite holocellulose. The dried chlorite holocellulose was treated with 24% KOH solution for 4 h with occasional stirring in the fiber liquor ratio of 1:100. With this treatment hemicellulose goes into solution and a-cellulose remains compact. It is then separated by filtration, washed thoroughly with 2% acetic acid solution, and finally, with distilled water. The amount of a-cellulose obtained was deducted from the weight of holocellulose taken, which gives the amount of hemicellulose.
Bleached PALF was dyed with Direct Green 27 and Acid Orange 52 in a dye bath at 60°C for 60 min, and the pH of the dye bath was adjusted at 4. The fiber liquor ratio was maintained 1:30. In order to measure dye ability, as well as absorption of dye percentage of the bleached fiber dyed with direct and acid dyes, were examined in a colorimeter (Model 6051).
Absorption of dye percentage = Do-De / Do x 100
where Do is the original dye bath concentration and De is the exhausted dye bath concentration. The photooxidative degradation of bleached pineapple leaf fiber was exposed to sunlight with the presence of air. The irradiation time lasted up to 300 h.
Journal of Natural Fibers, 6:138–150, 2009 ISSN: 1544-0478 print/1544-046X online
Journal