Fabrication of alkali cellulose
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Sheet cellulose is mercerized in two stages. In the first stage, 4-6-fold swelling of the cellulose takes place for 30–60 sec, and the alkali penetrating the swollen sheet is depleted due to chemical binding of NaOH. In the second stage, which lasts for 1–2 h, diffusion leveling of the concentrations takes place, and the amount of chemically bound NaOH increases by 10–15%. In the continuous method of sheet mercerization, treatment with alkali lasts for 30–60 sec, and to ensure the required amount of chemically bound NaOH, its concentration in the working solution is increased by 10–20%. Bulk mercerization, where cellulose filaments with a cross section of 0.03 mm are accessible to the alkali, takes place in 1–5 sec, since the diffusion stage is almost absent in this case. The continuous method of mercerization of cellulose in bulk includes the positive aspects of the process conducted in a VA unit and in UNM-30 continuous mercerization units and is free of their drawbacks.
KeywordsPolymer Cellulose Organic Chemistry Require Amount Positive Aspect
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