Modified Cottonseed Oil Preparation Of Leather Fatliquor

With cottonseed oil as a raw material, systematical studies are done on the preparation techniques of fatliquoring agent through such processes as ester exchange, esterification, oxidation and sulphitation. The products are also been applied in fatliquoring process to evaluate their fatliquoring properties. The preparation techniques are analyzed and summarized. The product obtained is excellent in fatliquoring at last.By analyzing the influence of such influencing factors as time, temperature, dosage of methanol and catalyzer on the hydroxyl value and viscosity of the modified products, with the fatloquoring properties being considered, the proper preparation techniques are obtained at last. With the main structure of the oil constant, it may provide an easy condition for the esterification of the oil to try to introduce as more hydroxyl groups as possible to the oil. The proper ester exchange condition obtained at last is as follow: the mol ratio of oil and methanol is 1:2; the dosage of catalyzer is 0.9%; the temperature is 65 ℃; and the time is 4 hours.With the conversion of maleic anhydride as a criterion, the influence of such factors of esterifing temperature on the esterification is studied, and the proper temperature for the esterification is got. With the esterifing temperature constant, by the orthogonal test, the influence of the amount of maleic anhydride, the amount of catalyzer, esterification time on the esterification is studied, and the reaction condition is optimized. On the base of these studies, the factors that may affect the esterification are determined at last. The proper esterification condition is: the amount of maleic anhydride should be 15% of the modified oil in weight; the amount of catalyzer should be 1.5% of the modified oil in weight; the esterification temperature should be 130 ℃; and the esterification time should be 4 hours.As to the oxidation process, with acetic acid as oxygen-carrying agent, vitriol as catalyzer, and H₂O₂ as oxidizer, the double-bonds of the esterified oil are oxidated. After the oxidation products being separated by water washing, the influence of such factors as temperature, time and the amount of oxidation agent on the iodine value and the POV, when the oxidation reaction being conducted, is studied. The properoxidation process is obtained as follows: the amount of hydrogen peroxide is 40% of the modified oil in weight; the reaction temperature is 55 °C; the reaction time is 4 hours.The self-emulsible abality, the size of the emulsion particles and the permeation degree of the fatlaquoring agent are determined by the sulphitation degree. The influence of temperature, time, POV and the amount of sodium bisulfite on the sulphitation degree is studied by the bi-phase titration method. The fatliquoring agents are applied in the process of leather. A proper sulphitation condition is got as: the amount of sodium bisulfite is 30% of the oxidated oil in weight, the temperature is 65 °C, and the reaction time is 3 hours.The fatliquoring agent with proper components is achieved from raw cottonseed oil through ester exchange, esterification, oxidation, sulphition and application in leather. For further improvement the general behaviors and the emulsion stability of the products, chlorcosane and silicone oil are chosen to combine with sulphitated oil according to an orthogonal test. The composite is applied in the fatliquoring of leather, and the quality of the leathers is judged. The proper proportion among of sulphited oil, chlorcosane, and silicone oil in weight is 25:6:2.