Polyethylene glycol (PEG) is very common and is useful in various industries. It mainly neutralizes the acidity of fillers in rubber, accelerates the vulcanization rate and crosslinking density, has good water solubility, and has many organic components. Good compatibility, with excellent lubricity, moisturizing and dispersing properties. It can also be used as antistatic agent and softener.

Generally, PEG-4000 is used in the rubber. If the molecular weight is too low, the compatibility is not good and it is easy to separate out, and it is liquid, it is not easy to add, the molecular weight is too high, the alcohol mass per unit mass is few (low hydroxyl value), and the acidity is neutralized The effect is poor, because the molecular weight of 4000 is solid flake, easy to process, easy to add, difficult to precipitate, and the polymer with medium molecular weight has better compatibility with rubber, so PEG-4000 is generally selected.