INVESTIGATION OF THE EFFECT OF CARBOXYMETHYL CORN STARCH ON RETANNING AND DYEING PROCESSES
Project no. 1341 · Status: Kapanmış · 2018
Summary
Starch has been a research subject in many industries as an abundant, inexpensive, renewable, natural polymer for producing of sustainable environmental chemicals in recent years. In order to reduce the pollution load that occurs in leather industry, using the environmentally friendly chemicals in processes that create the pollution load such as liming, retanning and dyeing has a great importance. For this purpose, in the presented study, utilization of modified starch in leather making as a retanning agent and its effect on dyeing process were investigated. Within the scope of the project, firstly, native corn starch whose molecular size/weight is too large for penetrating between leather fibers was oxidized with H2O2 to reduce its molecular size/weight then obtained oxidized starch was subjected to carboxymethylation process for introducing carboxymethyl groups into the structure of oxidized starch. The product yields, water solubility and degree of substitutions of oxidized and carboxymethylated starches were determined, also structure analysis by FTIR, 1H-NMR, 13C-NMR and thermal analysis by DSC were carried out to determine the changes occurring in native starch structure by oxidation and carboxymethylation processes. In the second stage of the project, carboxymethylated starch were used to be %3, 5 and 10 ratios in retanning process of wet-blue goat leather pieces and the occurring changes in shrinkage temperatures and filling coefficients of leathers were determined. In addition, two different types of dyes, acid and metal complex dyestuffs were used in dyeing process of leathers retanned in different proportions, and the effect of carboxymethyl starch on dyeing was also investigated by determining the amount of dye remaining in the floats, dry and wet rubbing fastness and color differences. The results revealed that carboxymethyl corn starch can be used as a sustainable environmentally friendly retanning agent and dyeing auxiliary in leather production.