Abstract:
In recent years, the development of biodegradable materials from renewable natural resources has received increasing attention. In Thailand, bagasse fiber is an extremely abundance waste product from sugar production. Bagasse fiber has increased interest due to environmentally friendly and high fiber content. However, bagasse fiber is colorless and difficult to dye. Chitosan, derived from chitin, is a biopolymer that performed higher adsorption capacity of dye. This research aimed to study the effect of dye adsorption on bagasse fiber with chitosan solution and microchitosan emulsion as a dye absorber. The dyeing formulations of bagasse fiber were prepared by mixing bagasse pulp dispersion in water with chitosan solution or microchitosan emulsion. Two types of food grade dyes with various amounts were used in this study (tartrarzine and ponceau 4R), at 1% by wt sizing agent (alkyl ketone dimer, AKD) were also added. The experiments were carried out at different chitosan dosages of 5, 10, 15, 20 and 25% by wt. Various dye dosages of 5, 10, and 20% by wt were used in bagasse pulp formulation. After that, each formulation was processed into paper sheet according to TAPPI T250 standard. Physical and mechanical properties of the obtained paper sheets were investigated. The results from color measurement (CIELab) indicated that the brightness (L*) of the paper sheets decreased, a* had positive value (red color), b* had positive value (yellow color) and color strength (K/S) increased when the amount of chitosan solution and microchitosan emulsion increased. Paper sheets prepared with both dyes showed physical properties in the same fashion. The tensile strength, tear strength, air resistance and burst strength increased when the amount of the chitosan increased at 20% by wt of dye contents. However, the tear resistance and water resistance decreased as the chitosan solution and microchitosan emultion used in formula increased.