Messi Biology states that magnesium oxide (MgO) serves primarily as a neutralizing agent in the production of acetate fiber. It’s used to regulate the acid-base balance, improve fiber quality, and plays a crucial role in the stability and processing performance of the final product. Here’s a detailed look at the functions of magnesium oxide in acetate fiber production:
1. Regulating the Acid-Base Balance
During the production of acetate fiber, acetic anhydride is used to esterify cellulose, which typically generates a highly acidic environment (e.g., excess acetic acid and sulfuric acid). If the acidity is too high, it can affect the uniformity, thermal stability, and processing performance of the final fiber product.
- Alkaline Effect of Magnesium Oxide: MgO can react with excess acid to form magnesium acetate (Mg(CH₃COO)₂), thereby neutralizing surplus acid and improving the stability of the reaction system.
- Reducing Acidic Degradation: If excess acid in the system isn’t neutralized, it can lead to fiber degradation, reducing the fiber’s strength and durability.
2. Promoting the Stability of Acetate Fiber
The performance of acetate fiber largely depends on its molecular weight, degree of polymerization, and thermal stability. Magnesium oxide plays an important role in these aspects:
- Inhibiting Fiber Degradation: During production, excessive acidity can trigger fiber degradation, causing the fiber to become brittle and reducing its tensile properties. Magnesium oxide can effectively buffer this acidity, reducing fiber breakage and degradation.
- Improving Thermal Stability: A suitable amount of magnesium oxide can make the fiber more stable during high-temperature processing (e.g., ironing, heat setting), preventing color changes or degradation.
3. Influencing the Physical Properties of Acetate Fiber
Magnesium oxide directly affects the fiber’s strength, softness, dyeing performance, and other physical characteristics.
- Enhancing Fiber Strength: The presence of magnesium oxide reduces the destructive effects of acidity on the fiber structure, making the fiber more resilient.
- Improving Dyeing Performance: An appropriate amount of magnesium oxide helps adjust the surface activity of the fiber, making it easier for dyes to penetrate and improving dyeing uniformity.
- Reducing Static Electricity Accumulation: Acetate fiber is prone to generating static electricity. The addition of MgO in the right amount can alleviate static electricity problems, improving textile processing performance.
4. Influencing Process Control in Acetate Fiber Production
The method of adding magnesium oxide, its particle size, and its reactivity all affect its effectiveness in acetate fiber production.
- Smaller particle sizes lead to better dispersibility, helping to neutralize acidity more evenly and improving reaction efficiency.
- Highly reactive magnesium oxide has better solubility, allowing it to participate rapidly in the neutralization reaction, improving production efficiency.
- Excessive magnesium oxide can lead to precipitation or impurities, affecting the fiber’s transparency and gloss. Therefore, precise control of the dosage is necessary.
5. Environmental Protection and Sustainability
Magnesium oxide not only improves the efficiency of acetate fiber production but also plays a role in environmental protection:
- Reducing Acidic Wastewater Discharge: During production, magnesium oxide can react with acidic wastewater, reducing the acidity of the wastewater and lessening the environmental impact.
- Recyclable and Reusable: Some magnesium oxide can be recovered and reused during production, improving resource utilization.