Determination of wood and bark chemical composition of Turkish hazelnut (Corylus colurna L.) and evaluation of tannin extracted from bark with various methods

The chemical characterization of Turkish hazelnut (Corylus colurna L.) wood and its barks and its use in the leather industry were investigated. This master's thesis has been prepared Düzce University Graduate School of Natural and Applied Sciences Department of Forest Industry Engineer. Turkish hazelnut (Corylus colurna L.) which has a natural distribution within the boundaries of the Sazakici Forestry Management Department of Bolu Forest Regional Directorate has been selected as the material. For this purpose the basic chemical analyzes have been applied. In bark samples, tannin production experiments were carried out at various concentrations and ratios of the solvents. These experiments included hot water, 1%, 2% and 5% sodium hydroxide (NaOH), 1%, 2%and 5%sodium sulphite (Na2SO3) and 1%, 2% and 5% sodium carbonate Na2CO3. In addition, these solutions were used to extract bark samples in 1/6, 1/8 and 1/10 ratios and the resulting yields were calculated. From these experiments 1/8 ratio of hot water and 1/8 ratio of 2% sodium hydroxide (NaOH) solution were determined as the optimum solvents for tannin production. In addition, analyzes of Stiasny number and methanol: water (4: 1) solubility determinations with hot water, NaOH and Na2SO3 were also performed. It has been found that the quantitative chemical composition values are within the limits of the values in the literature. As a result of application of the obtained tannin on the leather, the effect on the thickness and color was observed. The increase in leather thickness was shown to be adequate for shoemaking, accessory and bags where visual effects are requested.