What is the effect of adding p-nonylphenol before VC distillation?
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Nonylphenol acts as a polymerization inhibitor in VC polymerization; does it have an impact on the molecular weight distribution of the resulting resin? Do other manufacturers use this method before distillation?
When used in the appropriate amount, it has no effect on the molecular weight of the product. Nonylphenol can be added before distillation to prevent VC from self-polymerizing in the low-boiling and high-boiling towers as well as other equipment and pipelines.
Some manufacturers add nonylphenol to the gas pipeline at the inlet of the total condenser to slow down the auto-polymerization of the pipes in the distillation tower and its associated equipment.
Reduce tray self-polymerization; if the self-polymerization problem in sieve plate towers is not severe, there is no need to add anything. α**ethylene can also be added, but not in large quantities, as too much of it will affect the polymerization reaction cycle.
Nonylphenol primarily serves to prevent the self-polymerization of vinyl chloride monomer.
At present, our company has not done this yet. If there is severe self-polymerization of the trays or pipes in the high and low boiling towers of the distillation system, it can be added. Although it is a polymerization inhibitor, it should not be used in large quantities, as too much of it will affect the polymerization time. Some manufacturers add it to both the full condenser and the high and low towers
Adding some ATSC before distillation can also reduce self-polymerization
The anti-distillation effect of the column is not very significant; what’s important is to use trays with a better anti-self-condensation effect, as well as to operate the column carefully!
I disagree with the view on floor 7, because ATSC can be easily broken down into TSC, and TSC is one of the main reasons for the formation of coarse particles; therefore, adding some ATSC before distillation can also reduce self-polymerization, but it still has the drawback of leading to the formation of coarse particles
Before entering the distillation process, an anti-polymerization agent must be added to the recycled material. This agent does not end up in the material after distillation; instead, it is discharged at the bottom of the tower as a heavy component. Unless the tower is blocked or there is an abnormality. The inhibitor can be TBC (tert-butylhydroquinone), at a concentration of over 200 ppm.