Natural Rubber (NR)
Natural Rubber is made from latex collected from rubber trees and is a polymer of isoprene. It has excellent abrasion resistance, high elasticity, tensile strength, and elongation. It ages easily in air, becomes sticky when heated, and easily swells and dissolves in mineral oil or gasoline. It is alkali-resistant but not resistant to strong acids. It is a raw material for making tapes, hoses, and rubber shoes, and is suitable for making shock-absorbing parts and products used in automotive brake fluid, ethanol, and other hydroxyl-containing liquids.
Styrene-Butadiene Rubber (SBR)
Styrene-butadiene rubber (SBR) is a copolymer of butadiene and styrene. Compared to natural rubber, it has more uniform quality and fewer impurities, but its mechanical strength is weaker. It can be blended with natural rubber.
Butyl Rubber (IIR)
Butyl rubber is polymerized from isobutylene and a small amount of isoprenes. It retains a small number of unsaturated groups for vulcanization. Due to the steric hindrance of methyl groups, its molecular motion is less than other polymers, resulting in lower gas permeability. It exhibits high resistance to heat, sunlight, and ozone, and excellent electrical insulation. It also shows high resistance to polar solvents such as alcohols, ketones, and esters. Its typical operating temperature range is -54~110℃.
Ethylene Propylene Rubber (EPDM)
Ethylene propylene rubber is copolymerized from ethylene and propylene. Its main chain does not have double chains, resulting in excellent heat resistance, aging resistance, ozone resistance, and stability. However, it cannot be vulcanized. To address this issue, a small amount of a third component with double chains is introduced into the EP main chain, allowing for vulcanization, thus creating EPDM. Its typical operating temperature range is -50~150℃. It exhibits excellent resistance to polar solvents such as alcohols, ketones, ethylene glycol, and phosphate ester hydraulic fluids.
Nitrile Rubber (NBR)
Nitrile rubber is copolymerized from acrylonitrile and butadiene. The acrylonitrile content ranges from 18% to 50%. Higher acrylonitrile content provides better resistance to petrochemical oils and hydrocarbon fuels, but lower low-temperature performance. The typical operating temperature range is -25 to 100°C. Nitrile rubber is one of the most commonly used rubbers for oil seals and O-rings.
Chlorosulfonated Polyethylene Rubber
Chlorosulfonated polyethylene (Hypalon, Polyethylene) is a patented synthetic rubber from DuPont. It has excellent heat resistance, weather resistance, and ozone resistance; it also has good acid resistance and is commonly used in applications requiring resistance to oxidizing agents (nitric acid, sulfuric acid). The typical operating temperature range is -45 to 120°C.