Magnesium oxide is mainly used as a neutralizer in the production of acetate fiber to adjust the acid-base balance, improve the fiber quality, and play a key role in the stability and processing performance of the final product. The following are the specific roles of magnesium oxide in the production of acetate fiber:
1. Adjusting acid-base balance
In the production process of acetate fiber, the esterification reaction of cellulose with acetic anhydride usually produces a strong acidic environment (such as excess acetic acid and sulfuric acid). If the acidity is too strong, it will affect the uniformity, thermal stability and processing performance of the fiber.
Alkaline effect of magnesium oxide: MgO can react with excess acid to generate magnesium acetate (Mg(CH₃COO)₂), thereby neutralizing excess acid and improving the stability of the reaction system.
Reduce acid degradation: If the excess acid in the system is not neutralized, it will cause fiber degradation and reduce fiber strength and durability.
2. Promote the stability of acetate fiber
The performance of acetate fiber depends largely on its molecular weight, degree of polymerization and thermal stability, and magnesium oxide plays an important role in these aspects:
Inhibit fiber degradation: During the production process, excessive acidity will cause fiber degradation, resulting in fiber brittleness and reduced tensile properties. Magnesium oxide can effectively buffer this acidic effect and reduce fiber breakage and degradation.
Improve thermal stability: The appropriate magnesium oxide content can make the fiber more stable during high-temperature processing (such as ironing and heat setting), and it is not easy to change color or degrade.
3. Affect the physical properties of acetate fiber
Magnesium oxide has a direct impact on the strength, softness, dyeing properties, etc. of the fiber.
Enhance fiber strength: The presence of magnesium oxide can reduce the damage of acidity to the fiber structure and make the fiber more resilient.
Improve dyeing properties: The right amount of magnesium oxide helps adjust the surface activity of the fiber, making the dye easier to penetrate and improving dyeing uniformity.
Reduce static electricity accumulation: Acetate fiber is prone to static electricity, and the right amount of MgO can alleviate the static electricity problem and improve textile processing performance.
4. Process control affecting the production process of acetate fiber
The addition method, particle size, and activity of magnesium oxide will affect its effect in the production process of acetate fiber.
The smaller the particle size, the better the dispersibility, which helps to neutralize the acidity more evenly and improve the reaction efficiency.
Highly active magnesium oxide has better solubility and can quickly participate in the neutralization reaction to improve production efficiency.
Excessive magnesium oxide may cause precipitation or impurities, affecting the transparency and gloss of the fiber, so the dosage needs to be precisely controlled.
5. Environmental protection and sustainability
Magnesium oxide can not only improve the production efficiency of acetate fiber, but also play a role in environmental protection:
Reducing acidic wastewater discharge: During the production process, magnesium oxide can react with acidic waste liquid to reduce the acidity of wastewater, thereby reducing the impact on the environment.
Recyclable: Some magnesium oxide can be recycled and reused during the production process to improve resource utilization.