Polyethylene glycol (PEG) is very commonly used and is used in all walks of life. In rubber, it mainly neutralizes the acidity of fillers and speeds up vulcanization speed and cross-linking. It has good coupling density, good water solubility and good compatibility with many organic components. It has excellent lubricity, moisturizing and dispersing properties, and can also be used as an antistatic agent and softener.
Generally, PEG0 is used in rubber. If the molecular weight is too low, the compatibility is not good and it is easy to precipitate. Moreover, it is a liquid and is difficult to add. The molecular weight is too high and the unit mass There are few alcohol groups (low hydroxyl value), and the effect of neutralizing acidity is poor, because the molecular weight of polyethylene glycol 0 is in the form of solid flakes, which is easy to process, easy to add, not easy to precipitate, and polymerizes with medium molecular weight. It has better compatibility with rubber, so PEG-0 is generally chosen.
Polyethylene glycolThe role of PEG
1. Processing aids can increase the extrusion speed of the rubber compound, improve the demoulding properties, make the surface of the product bright, and help discharge moisture during vulcanization. When used in tires and rubber molded products,polyethylene glycol0It has good lubrication effect and makes the surface of the product smoother. In the production process of natural rubber and synthetic rubber, it can also be used as an internal release agent. The advantage is that it is non-volatile, does not produce graying, and the mold remains clean after demoulding. Moreover, the surface of molded products is smoother and cleaner due to its addition.
2. Vulcanization activator plays the role of adjusting the bonding properties of raw rubber and fillers (especially white). It also has the function of reducing Mooney and increasing the vulcanization rate. It especially has a good activation effect on thiazole accelerators and can improve Vulcanization speed and degree of cross-linking. Especially in the formula of EPDM white CB reinforced extrusion microwave continuous vulcanization. It is best not to use PEG for products bonded to metal.
3. The activator of acidic fillers, especially for silica, can be used as a treatment agent for silica to activate the vulcanization system. Wetting the surface of acidic fillers such as silica. A reactive rubber additive is neutralizing, and one is similar to covering. Because acidic fillers will adsorb, please note that they are adsorption accelerators. The usage amount is directly proportional to the acidic surface area of the acidic filler, etc. We can basically understand that the acidic surface has been neutralized. Of course, acidity will also occur in other vulcanization reactions, such as HS, etc. Let zinc oxide take care of that.
4. Activated dispersant, when used as an activated dispersant in rubber compounds using various fillers and pigments, can reduce or eliminate the influence of fillers on vulcanization, make various additives disperse evenly, prolong scorch time, and improve Physical and mechanical properties of rubber products. Among all kinds of colored rubber products, the products can be brightly colored.
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