Polyethylene glycol (PEG) is very commonly used and is useful in all walks of life. In rubber, it mainly neutralizes the acidity of fillers, accelerates vulcanization speed and crosslinking density, has good water solubility, and is compatible with many organic components. Good compatibility, excellent lubricity, moisture retention, dispersibility, and can also be used as antistatic agent and softener.

Generally, PEG-4000 is used in rubber. If the molecular weight is too low, the compatibility is not good, it is easy to separate out, and it is liquid, not easy to add, the molecular weight is too high, the alcohol group per unit mass is small (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, not easy to precipitate, and the polymer of medium molecular weight has better compatibility with rubber, so PEG-4000 is generally selected.

☆The role of PEG can be summarized as follows:
1. Processing aids can increase the extrusion speed of the rubber compound, improve the mold release, make the surface of the product bright, and also help to discharge water during vulcanization. When used in tires and rubber molded products, PEG-4000 has a good lubricating effect, making the surface of the products 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 does not volatilize, does not produce ash, and the mold remains clean after demolding. And the surface of the molded product is also smoother and cleaner due to its addition.

2. Vulcanization activator, plays the role of regulating the binding properties of raw rubber and filler (especially white), and also reduces Mooney and improves the vulcanization rate, especially has a good activation effect on thiazole accelerators, can improve Vulcanization rate and degree of crosslinking. Especially in the formulation of EPDM white CB reinforced extrusion microwave continuous vulcanization. Products bonded to metal preferably do not use PEG

3. Activating agents for acidic fillers, especially for silica, can be used as a treatment agent for silica to activate the vulcanization system. Wet the surface of acidic fillers such as silica. One reaction is neutralization and one is similar to covering. Because acidic fillers will adsorb, please note that they are adsorption enhancers. The amount used is proportional to the amount of acidic surface area of the acidic filler, etc. We can basically understand that the acidic surface has been neutralized. Of course, other vulcanization reactions will also appear acidic, such as HS. I'll leave that to Zinc Oxide.

4. Activated dispersant, when used as an activated dispersant in the rubber compound of various fillers and pigments, can reduce or eliminate the influence of fillers on vulcanization, make various additives evenly dispersed, prolong the scorch time, and improve the physical properties of rubber products. Mechanical behavior. In all kinds of colored rubber products, it can make the products bright in color. Due to its polar characteristics, it can also enhance the absorption of microwaves by non-polar rubbers (such as EPDM).