EPDM rubber and EPDM reclaimed rubber have excellent weather resistance and are often used to produce rubber products that require long-term exposure to sunlight, hot oxygen, ozone, damp heat, etc., and delay rubber products in the above conditions. The aging time; so why is the EPDM compound excellent in weather resistance? What other factors will affect the weatherability of EPDM rubber?
1. Why is the EPDM compound excellent in weather resistance?
EPDM rubber is a copolymer of ethylene, propylene and a small amount of non-conjugated diene. Its main chain is composed of chemically stable saturated hydrocarbons. Only a small amount of unsaturated double bonds are contained in the side chain. The molecular chain is stable and not The saturation is extremely low, the unique molecular structure gives the EPDM excellent weather resistance; the EPDM reclaimed rubber is a recycled rubber processed from EPDM waste rubber and waste EPDM rubber products, retaining the original EPDM rubber. Some performance characteristics, including its weather resistance.
2. What are the factors affecting the weather resistance of EPDM compounds? How to improve the weather resistance of rubber products?
(1) Diene content affects the weather resistance of EPDM rubber
Studies have shown that the weather resistance of EPDM rubber is related to the content of diene. The molecular stability of EPDM rubber will decrease with the increase of diene content, resulting in poor weather resistance of EPDM rubber. . When using EPDM rubber and EPDM reclaimed rubber to produce rubber products with extremely strict weather resistance requirements, it is necessary to select a rubber compound with a low diene content to extend the service life of the rubber products.
(2) Some rubber fillers can improve the weatherability of EPDM compounds
The type and amount of filler in the rubber product formulation also affects the weatherability of the EPDM article. As the most commonly used reinforcing agent in the rubber products industry, carbon black itself has strong absorption of ultraviolet light. The smaller the particle size, the larger the amount, the more obvious the absorption effect on ultraviolet rays; the use of EPDM rubber or EPDM reclaimed rubber When producing black and dark rubber products, the amount of small particle size carbon black can be increased as much as possible. When the EPDM rubber is used to produce light-colored rubber products, the rubber product formulation can be filled with appropriate amount of titanium dioxide and zinc oxide to improve the weather resistance of the EPDM recycled rubber products.
(3) Rubber anti-aging agent significantly delays the aging time of EPDM products
Adding an appropriate amount of anti-aging agent to the rubber product formulation can delay the aging time and prolong the service life of the rubber product; among them, the amine anti-aging agent, the anti-aging agent NBC, the p-phenylenediamine anti-aging agent, the phenol anti-aging agent, the paraffin wax and the ultraviolet absorber are all It can significantly improve the weather resistance of EPDM rubber products, especially anti-sunlight aging; it is necessary to pay special attention to the fact that p-phenylenediamine anti-aging agent has excellent anti-sunlight aging effect, but its color change is serious and cannot be used in shallow Color and color EPDM rubber products are produced.
Both EPDM rubber and EPDM reclaimed rubber have excellent weather resistance. Selecting the rubber compound variety, rationally adjusting the reinforcing filling system and anti-aging system in the rubber product formula can further improve the EPDM rubber products. Weather resistant, extending the life of EPDM products.