What factors of the refined cotton are related to the stability of nitrocellulose?
Thread Content
I need some advice! I’m a beginner and am in charge of managing the nitrocellulose production process. Recently, there have been issues with the heat resistance of the nitrocellulose produced. Upon checking the process, I found that there weren’t any major problems with the operations. Someone then suggested that the issue lay with the refined cotton, but I don’t understand this!
The production of nitrocellulose (NC) is more complex than the processes discussed in the previous chapters; it involves mainly three steps: ① Refining cotton to obtain； ②esterification ； ③Stabilization treatment. Ordinary cotton contains a large amount of dust and impurities, and it is covered with a layer of fat on its fibers, making it completely unsuitable for use in esterification. When used in medical applications, refined cotton is referred to as pharmaceutical cotton. Absorbent cotton is produced by removing mechanical impurities from cotton linters, followed by washing, pressure alkali treatment, rinsing, and other processes; it involves a relatively complex manufacturing procedure. Here is a simplified method of production, which is not suitable for large-scale manufacturing. Production from refined cotton: the highest-quality cotton, sodium hydroxide (NaOH, industrial grade), and water. Method: Tear the cotton apart and remove any visible impurities such as small stones and dead leaves. Rinse the cotton with water until the runoff is clear. Place the cotton in an enamel pot, add water until it just covers the cotton, then add NaOH in an amount equivalent to 2%–5% of the weight of the water. Cover the pot, bring to a boil, and then simmer for 10 minutes on low heat. Cool down, then rinse thoroughly with plenty of water – scrubbing for about 10 minutes while rinsing. Place the washed cotton on clean paper to dry. Note: Caustic solution (NaOH) is highly corrosive; gloves and plastic aprons must be worn, and any contact with the skin should be washed off immediately. Do not cook for too long, to avoid a decrease in polymerization degree, which could affect esterification. Be careful to avoid dust during drying.
Teacher upstairs, could you please provide some information on the industrial production process and equipment related to nitrocellulose? I really need to know this. If you have any detailed materials, please let me know how to get in touch. Let’s communicate separately. Thank you!