Basic Properties Of Rubber Required For Rubber Sheet Production

1. Natural rubber NR

(Natural Rubber) It is made of latex collected from rubber tree and is a polymer of isoprene. It has good abrasion resistance, high elasticity, breaking strength and elongation. It is easy to age in the air and change when exposed to heat. Sticky, easy to swell and dissolve in mineral oil or gasoline, resistant to alkali but not strong acid.

Advantages: good elasticity, acid and alkali resistance.

Disadvantages: Not weather-resistant, not oil-resistant (vegetable oil-resistant) is the raw material for making tapes, hoses, and rubber shoes, and is suitable for making shock-absorbing parts, products used in automotive brake fluid, ethanol and other liquids with hydroxide radicals.

2. SBR

(Styrene Butadiene Copolyme) Copolymer of butadiene and styrene, compared with natural rubber, has uniform quality, less foreign matter, good abrasion resistance and aging resistance, but weaker mechanical strength, blended with natural rubber use.

Advantages: Low-cost non-oil-repellent material, good water-resistance, good elasticity below 70 hardness, poor compressibility at high hardness.

Disadvantages: Strong acids, ozone, oils, oil esters and fats and most hydrocarbons are not recommended. Used in tire industry, shoe industry, cloth industry and conveyor belt industry, etc. SBR has good heat resistance, abrasion resistance, aging resistance, oil resistance and ozone resistance. Good storage stability, can be stored for several years in the dark. Soluble in benzene, toluene, xylene, ethyl acetate, chloroform and other solvents.

3. Butyl Rubber IIR

(Butyl Rubber) is the polymerization of isobutylene and a small amount of isoprene. Because the movement of the steric barrier molecule of methyl group is less than that of other polymers, it has less gas permeability and is resistant to heat, sunlight and ozone. Large, good electrical insulation; high resistance to and capacitive agents, the general operating temperature range is -54-110 ℃.

Advantages: Impermeability to most common gases, good resistance to sunlight and odors, exposure to animal or vegetable oils or vaporizable chemicals.

Disadvantages: It is not recommended to use it with petroleum solvent, kerosene and aromatic hydrogen. It is used for inner tube, leather bag, rubber paste paper, window frame rubber, steam hose, heat-resistant conveyor belt, etc. of automobile tires.

4. Neoprene CR

(Neoprene, Polychloroprene) is polymerized from chloroprene monomer. The rubber after vulcanization has good elasticity and wear resistance, is not afraid of direct sunlight, has good weather resistance, is not afraid of severe distortion, and is not afraid of refrigerants, It is resistant to dilute acid and silicone ester series lubricating oil, but not resistant to phosphate ester series hydraulic oil. It is easy to crystallize and harden at low temperature, has poor storage stability, and expands greatly in mineral oil with low aniline point. The general operating temperature range is - 50~150℃.

Advantages: good elasticity and good compression deformation, the formula does not contain sulfur-sulfur, so it is easy to make. It has the characteristics of resistance to animal and vegetable oils, and will not be affected by neutral chemicals, fats, oils, various oils, solvents. And affect physical properties, with imitation combustion characteristics

Disadvantages: It is not recommended to use strong acids, nitro hydrocarbons, esters, chloroform and ketones among chemicals. R12 refrigerant resistant seals, rubber parts or seals on household appliances. It is suitable for making parts that are in direct contact with the atmosphere, sunlight and ozone. It is used for various flame-resistant and chemical-resistant rubber products.

5. EPDM

(Ethylene propylene Rubber) is made of ethylene and propylene copolymer, so heat resistance, aging resistance, ozone resistance, and stability are all excellent, but sulfur-sulfur cannot be added. To solve this problem, in EP A small amount of the third component with double chains is added to the main chain and sulfur can be added to form EPDM. The general operating temperature is -50~150 ℃.

Advantages: It has good weather resistance and ozone resistance, can use alcohols and ketones, is resistant to high-temperature steam, and has 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 braking (brake) systems. Seal in radiator (car radiator).

6. Nitrile NBR

(Nitrile Rubber) Copolymerized by acrylonitrile and butadiene, the content of acrylonitrile is 18%~50%. The higher the content of acrylonitrile, the better the resistance to petrochemical hydrocarbon fuel oil, but the low temperature The performance becomes worse, and the general operating temperature range is -25~100 ℃. Nitrile rubber is one of the commonly used rubbers for oil seals and O-rings.

Advantages: good oil resistance, water resistance, solvent resistance and high pressure oil resistance, good compressibility, wear resistance and elongation force.

Disadvantages: Not suitable for use in aggressive solvents, such as ketones, ozone, nitro hydrocarbons, MEK and chloroform. Used to make fuel tanks, lubricating oil tanks and in petroleum-based hydraulic oil, gasoline, water, silicone oil, diester system The rubber parts used in fluid media such as lubricating oil are sealing parts. It can be said that it is the most widely used and low-cost rubber.

7. Glue seals

(Hydrogenate Nitrile) Hydrogenated nitrile rubber is a nitrile rubber that has been hydrogenated to remove some double chains. After hydrogenation, its temperature resistance and weather resistance are much higher than that of general nitrile rubber, and its oil resistance is the same as that of general nitrile rubber. glue is close. The general operating temperature range is -25~150 ℃.

Advantages: better abrasion resistance than nitrile rubber, good corrosion resistance, tensile strength, tear resistance and compression properties, good resistance-resistance under atmospheric conditions such as ozone, generally suitable for laundry or dishwashing detergent.

Disadvantages: Not recommended for use in alcohols, esters or aromatic solutions. Air-conditioning and refrigeration industry. Seals for environmental protection refrigerant R134a systems. Automotive engine system seals.