The effect of dispersants on polymerization
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Dispersants not only affect the particle morphology of the resin but also have a significant impact on fish eyes, especially 72.5PVA.
How to do a fisheye effect? Please explain in detail! At the same time, I would like to learn about methods to reduce the use of resin in fish eyes
Dispersants possess protective and dispersing capabilities, and the quality of these dispersants directly affects the particle morphology of the product. Fish eyes are transparent PVC particles that have not been plasticized under thermoplasticization conditions. Reasons for fish-eye effect: 1. Poor water quality. 2. The content of high-boiling substances in the monomer is too high. 3. The discharge is not stable.
Reply to 2# zthx2010: Strengthen flushing during discharge to improve the quality of pure monomer, and enhance water quality monitoring
Reply to 1# kansam: The main functions are as follows: First, it reduces the interfacial tension between VC and water, which facilitates the dispersion of VC under stirring. Second: it serves to preserve the gel structure, preventing droplets from merging. Impact: The amount of dispersant used is determined based on the requirements of the product. Too much not only is uneconomical, but also increases the viscosity of the system, leading to severe sticking of the gas phase to the reactor walls and causing the resin particles to become finer. Too little; it cannot provide stability. It easily produces coarse material.
Reply to 2# zthx2010: The formation of fish eyes has little to do with the dispersant; the main causes of fish eye formation are as follows: 1. Each time the contents of a reactor are discharged, the reactor is not thoroughly cleaned, resulting in a secondary reaction. 2 The coating agent has poor effectiveness or has become ineffective (oxidized). 3 The abrasion of the mechanical grinding rope is caused by iron filings.