Natural rubber NR
Natural Rubber is made from rubber latex collected from rubber trees and is a polymer of isoprene. It has good wear resistance, high elasticity, tensile strength, and elongation. It is prone to aging in the air, becomes sticky when exposed to heat, expands and dissolves easily in mineral oil or gasoline, and is alkali resistant but not strong acid resistant· It is a raw material for making tape, hose, and rubber shoes, and is suitable for making shock absorbing parts and products used in liquids containing hydrogen peroxide such as automotive brake oil and ethanol.
Styrene butadiene rubber S B R
Styrene Butadiene Copolyme is a copolymer of butadiene and styrene. Compared with natural rubber, it has uniform quality, less foreign matter, but weaker mechanical strength, and can be mixed with natural rubber for use.
Advantages:
·Low cost non oil resistant materials
·Good water resistance, with a hardness below 70 and good elasticity
·Poor compression distortion at high hardness
·Can use most neutral chemicals and dry, nourishing organic ketones
Disadvantages:
·It is not recommended to use strong acids, ozone, oils, esters, fats, and most hydrocarbons· Widely used in the tire industry, shoe industry, and? Fabric and conveyor belt industries, etc.
Butyl rubber IIR
Butyl rubber is formed by polymerization of isobutylene with a small amount of isoprene, retaining a small amount of unsaturated groups for sulfur addition. Due to the less movement of methyl steric hindrance molecules compared to other polymers, it has less gas permeability, high resistance to heat, sunlight, and ozone, and good electrical insulation; It has high resistance to polar solvents such as alcohols, ketones, and esters, and is generally used at temperatures ranging from -54 to 110 ℃.
Advantages:
·Impermeable to most general gases
·Good resistance to sunlight and ozone
·Can be exposed to animal or vegetable oils or oxidizable chemicals
Disadvantages:
·Not intended to be used together with petroleum solvents, kerosene, and aromatic hydrogen· Rubber parts used for making chemical resistant and vacuum equipment.
Hydrogenated nitrile rubber HNBR
Hydrogenated nitrile rubber is a type of nitrile rubber that removes some double chains after hydrogenation. After hydrogenation, its temperature and weather resistance are much improved compared to general nitrile rubber, and its oil resistance is similar to that of general nitrile rubber. The general temperature range for use is -25~150 ℃.
Advantages:
·Compared to nitrile rubber, it has better wear resistance
·Excellent corrosion resistance, tensile resistance, tear resistance, and compression deflection characteristics
·Good resistance to ozone, sunlight, and other atmospheric conditions
·Generally speaking, it is suitable for washing clothes or dishes with cleaning agents
Disadvantages:
·It is not recommended to use in alcohol, ester, or aromatic solutions· The air conditioning and refrigeration industry is widely used as a sealing element in environmentally friendly refrigerant R134a systems.
·Automotive engine system seals.
EPDM ethylene propylene adhesive
Ethylene propylene rubber is formed by copolymerization of ethylene and propylene into a main chain that does not have double chains. Therefore, it has excellent heat resistance, aging resistance, ozone resistance, and stability, but cannot be sulfurized with sulfur. To solve this problem, a small amount of the third component with double chains can be introduced into the EP main chain to form EPDM through sulfur addition. The general temperature range for use is -50~150 ℃. Excellent resistance to polar solvents such as alcohols, ketones, ethylene glycol, and phosphate hydraulic oils.
Advantages:
·Good weather resistance and ozone resistance
·Excellent water resistance and chemical resistance
·Alcohols and ketones can be used
·High temperature vapor resistance and good impermeability to gases
Disadvantages:
·Not recommended for food use or exposure to aromatic hydrogen· Seals for high-temperature water vapor environments.
·Sanitary equipment seals or parts.
·Rubber parts in the braking system.
·Seals in radiators (car water tanks).