Rubber products refer to the activities of producing various rubber products using natural and synthetic rubber as raw materials, and also include the production of rubber products from waste rubber.

1、 Types and characteristics of rubber

General purpose rubber

1. Natural rubber NR: It is made from the latex of rubber tree, and its basic chemical composition is cis-polyisoprene, which is a polymer of isoprene.

It is a raw material for making adhesive tapes, rubber hoses, and rubber shoes. It is suitable for making shock absorbing parts, and products used in automotive brake oil, ethanol, and other liquids with hydroxyl radicals.

Advantages: Good wear resistance, high elasticity, tensile strength and elongation, acid and alkali resistance, and good comprehensive performance.

Disadvantages: Not heat resistant, not oil resistant (resistant to vegetable oil), easy to expand and dissolve in mineral oil or gasoline, alkali resistant but not strong acid resistant. It is easy to age in the air and become sticky when exposed to heat.

2. Isoprene rubber IR: The full name is cis-1,4-polyisoprene rubber, a high cis synthetic rubber made from isoprene, which is produced by solution polymerization. Due to its similar structure and properties to natural rubber, it is also known as synthetic natural rubber.

It can replace natural rubber in the manufacture of truck tires and off-road tires, and can also be used to produce various rubber products.

Advantages: Like natural rubber, it has good elasticity and wear resistance, excellent heat resistance and good chemical stability, and superior quality uniformity and processing performance to natural rubber.

Disadvantages: The strength of raw rubber (before processing) is significantly lower than that of natural rubber.

3. Styrene butadiene rubber SBR: obtained by copolymerization of butadiene and styrene. It is the general synthetic rubber with the largest output, which can be divided into lotion polymerized styrene butadiene rubber, solution polymerized styrene butadiene rubber and thermoplastic rubber (SBR) according to the production method.

It is widely used in the tire industry, shoe industry, cloth industry, conveyor belt industry, etc.

Advantages: Low cost non oil resistant material, good water resistance, good elasticity when hardness is below 70, and poor compressibility when hardness is high. Compared with natural rubber, it has uniform quality, less foreign matter, better wear resistance and aging resistance, and good comprehensive performance and chemical stability, which can be mixed with natural rubber for use.

Disadvantages: Due to weak mechanical strength, it is not recommended to use strong acids, ozone, oils, oleates, fats, and most hydrocarbons.

4. cis-1,4-polybutadiene rubber BR: The full name is cis-1,4-polybutadiene rubber, which is obtained by solution polymerization of butadiene.

Most of them are used in the production of tires, while a small proportion are used in the production of cold resistant products, cushioning materials, adhesive tapes, rubber shoes, etc.

Advantages: After vulcanization, cis-1,4-polybutadiene rubber has particularly excellent cold resistance, wear resistance, and elasticity, with less heat generation under dynamic load, and good aging resistance. It is easy to be used together with natural rubber, neoprene, nitrile rubber, etc.

Disadvantages: Poor tear resistance and wet skid resistance.

Neoprene rubber CR: It is made from chloroprene as the main raw material through homopolymerization or copolymerization with a small amount of other monomers. The vulcanized rubber has good elasticity and wear resistance, and the formula does not contain sulfur. Therefore, it is very easy to make, with particularly good weather resistance, not afraid of intense distortion, not afraid of refrigerants, and is resistant to dilute acids and silicone ester based lubricants. The general use temperature range is - 50-150 ℃.

Neoprene rubber has a wide range of uses, such as making transportation and transmission belts, wrapping materials for wires and cables, manufacturing oil resistant rubber tubes, gaskets, and chemical resistant equipment linings. Produce various parts that directly contact the atmosphere, sunlight, and ozone. Suitable for various flame resistant and chemical resistant rubber products. It is not recommended to use R12 refrigerant resistant seals among strong acids, nitrohydrocarbons, esters, chloroform, and ketones, as well as rubber parts or seals on household appliances.

Advantages: It has good comprehensive properties, such as high tensile strength, water resistance, oil resistance, flame resistance, heat resistance, light resistance, aging resistance, oxidation resistance, and ozone resistance. Good elasticity and compression deformation, with resistance to animal and vegetable oils, without affecting physical properties due to neutral chemicals, fats, oils, and solvents, and with flame retardant properties. High chemical stability.

Disadvantages: High density, easy to crystallize and harden at room temperature, poor storage performance, poor electrical insulation performance, poor cold resistance, easy to crystallize and harden at low temperatures, and raw rubber is unstable during storage. Not resistant to phosphate based hydraulic oils. The expansion amount is large in mineral oils with low aniline points.

Ethylene propylene rubber EPDM: synthesized from ethylene and propylene as the main raw materials, with good chemical stability, and similar wear resistance, elasticity, and oil resistance to styrene-butadiene rubber. EPDM can be formed by introducing a small amount of the third component with double chains onto the EP main chain and adding sulfur. The general use temperature is - 50-150 ℃. Excellent resistance to polar solvents such as alcohol and ketone. It is widely used as tire sidewalls, rubber strips, inner tubes, and automotive components, as well as for wire and cable sheaths, and high-voltage and ultra-high-voltage insulation materials. Manufacture of light colored products such as rubber shoes and sanitary products. It can be filled with a large amount of oil and carbon black, and its product price is relatively low. It is commonly used as a seal or part for high-temperature water vapor environments, sanitary equipment, and other related products. Rubber parts in the braking (braking) system. A seal in a radiator (car water tank).

Advantages: Good weather resistance and ozone resistance, excellent water resistance and chemical resistance. Alcohol and ketones can be used, high temperature vapor resistance, and good impermeability to gases. Excellent heat resistance, aging resistance, ozone resistance, and electrical insulation stability,

Disadvantages: Not recommended for food use or exposure to aromatic hydrocarbons.

7. Butyl rubber IIR: It is polymerized from isobutylene and a small amount of isoprene. Due to the less movement of steric barrier molecules of methyl group than other polymers, it is generally used at a temperature range of - 54 to 110 ℃.

Commonly used for inner tubes, leather bags, rubber paste paper, window frame rubber, steam hoses, heat resistant conveyor belts, etc. of automotive tires.

Advantages: Impermeability to most gases, strong resistance to heat, sunlight, and ozone, and good electrical insulation; It is highly resistant to polar solvents and can be exposed to animal or vegetable oils or gasifying chemicals.

Disadvantages: It is not recommended to use together with petroleum solvents, glue kerosene, and aromatics.

II. Special type rubber

Special type rubber refers to rubber with certain special properties.

1. Nitrile rubber NBR: a polymer made from butadiene and acrylonitrile via lotion copolymerization. The higher the acrylonitrile content, the better the oil resistance, but the cold resistance will decrease accordingly. The general operating temperature range is 25-100 ℃ below zero. Nitrile rubber is known for its excellent oil resistance. It can be used in air at 120 ℃ or oil at 150 ℃ for a long time. Good electrical conductivity.

Widely used, mainly for oil resistant products, a variety of oil resistant gaskets, gaskets, sleeves, flexible packaging, flexible rubber tubes, printing and dyeing rubber rollers, cable adhesive materials, antistatic rubber products, etc. It has become an essential elastic material in industries such as automotive, aviation, petroleum, and photocopying. Various sealing products, flame retardant products, and phenolic compounds are used as structural adhesives,

Advantages: Good oil resistance, water resistance, solvent resistance, and high pressure oil resistance. Good compressibility, elongation, wear resistance, aging resistance, air tightness, and excellent adhesion performance.

Disadvantages: Not suitable for use in polar solvents such as ketones, ozone, and nitrohydrocarbons. MEK can be mixed with natural rubber for use. Ozone resistance, electrical insulation, and cold resistance are relatively poor.

Hydrogenated Nitrile Rubber HNBR: Nitrile rubber is made by removing part of the double chain after hydrogenation. Its temperature resistance and weather resistance are much higher than ordinary nitrile rubber, and its oil resistance is similar to ordinary nitrile rubber. The general operating temperature range is 25-150 ℃ below zero.

It is widely used in cleaning agents for washing clothes or dishes, as environmental friendly refrigerants, seals in R134a systems, and seals in automotive engine systems.

Advantages: Excellent abrasion resistance, excellent corrosion resistance, tensile resistance, tear resistance, and compressibility. Good resistance under atmospheric conditions such as ozone.

Disadvantages: Not recommended for use in alcohol, ester, or aromatic solutions.

Silicone rubber Q: The main chain is formed by alternating silicon and oxygen atoms, and the side chain is composed of carbon containing groups with organic groups on the silicon atoms. The largest amount is silicone rubber with ethylene side chains. It is both heat and cold resistant, and its operating temperature is between 100-300 ℃. It has excellent weather resistance, ozone resistance, and good insulation.

Silicone rubber products are biocompatible materials that are closely related to people's lives. Remote controls, keyboards, pos machines, scanners, mobile phones, electronic dictionaries, and phone cases are all related to silicone rubber. It is mainly used in the aviation industry, electrical industry, food industry, medical industry, etc. Colorless silicone rubber products are non-toxic and can be used as artificial organs for the beauty industry and physical therapy industry.

Advantages: High and low temperature resistance, ozone resistance, good electrical insulation.

Disadvantages: Low strength, poor tear resistance, and poor wear resistance.

Fluororubber FKM: Fluororubber is a synthetic polymer made from fluorinated monomers that undergo polymerization or polycondensation to obtain fluorine atoms attached to the carbon atoms of the main or side chain of the molecule. Due to the different fluorine containing monomers used, fluorine rubber has many varieties, which can be divided into fluorine containing olefin copolymers and nitroso copolymers. "Usually expressed by the number of fluorine atoms in the fluorine containing unit of the copolymer, such as fluororubber 23, which is a copolymer of vinylidene fluoride and chlorofluoroethylene.". According to chemical composition, it can be divided into fluorinated olefin like fluororubber, fluorosilicone rubber, nitroso fluororubber, fluorinated acrylate rubber, fluorinated phosphoronitrile rubber, perfluoroether rubber, etc.

It is widely used in fields such as modern aerospace, aviation, automobiles, petroleum, and household appliances, and is an irreplaceable key material in cutting-edge defense industries.

Advantages: High temperature resistance, oil resistance, corrosion resistance, oxidation resistance, solvent resistance, flame resistance, chemical resistance, and climate resistance.

Polysulfide rubber PSR: It is formed by condensation polymerization of dihaloalkanes with polysulfides of alkali metals or alkaline earth metals. In addition, there are polyurethane rubber, chlorohydrin rubber, acrylate rubber, etc., mostly used in combination with nitrile rubber.

Advantages: Excellent oil and solvent resistance,

Disadvantages: Low strength, poor aging resistance, processability, and odor.

6. Sponge rubber, also known as foam rubber, foam rubber or microcellular rubber, is a porous elastic material, which is the general name of various rubbers with pore structure. The pores of this type of porous material cover the entire material, and are divided into three types according to their structure: closed pores (the holes are not interconnected with each other), open pores (the holes are not completely separated from each other by the hole wall, and have a certain degree of connectivity), and mixed pores (both open and closed pore structures).

Microporous rubber mainly includes expanded rubber and sponge rubber. Including soft sponges, hard sponges, microbubble sponges, conductive sponges, magnetic sponges, water expandable sponges, composite sponges, etc.

Sponge rubber products are widely used in many fields such as sealing, shock absorption, heat insulation, sound insulation, printing and dyeing, and even ion exchange. They are widely used in aviation, automobiles, instruments, appliances, and packaging industries. Its appearance includes plate, strip, tube, roller, gasket, etc., with various specifications and shapes. Different usage conditions require different hole structures and pore sizes. Therefore, it is required to make corresponding adjustments in the formulation and processing technology to achieve corresponding performance.

2、 Use of rubber

Transportation

The rubber industry developed with the automotive industry. Rubber consumption accounts for a significant proportion in transportation. In sea, land, and air transportation, none of them can be separated from rubber products. For example, a Jiefang 4 ton truck requires more than 200 kilograms of rubber products, a hard seat carriage needs to be equipped with rubber products with a total weight of more than 300 kilograms, a 10000 ton ship requires nearly 10 tons of rubber products, and a jet airliner requires nearly 600 kilograms of rubber. Tyres used as transportation vehicles, rubber spring shock absorbing products for railway vehicles and automobiles, and passenger transport belts for large stores, stations, and subways. In addition, there are also "hovercraft" and "hovercraft" made of rubber.

2. Industrial mines

The industrial sector needs a large number of rubber products, large and small, with a wide variety of uses, and some have special requirements. The main products include adhesive tape, rubber hose, sealing gasket, rubber roller, rubber plate, rubber lining, and labor protection articles. In industries such as mining, coal, and metallurgy, tape, wire rope core conveyor belts, or synthetic fiber conveyor belts are used to transport finished products. The rubber lining of mining mills, which uses forged rubber instead of manganese steel, has increased its service life by two to four times and reduced noise. This product has been promoted worldwide.

3. Agriculture, forestry and water conservancy

In addition to various tires for tractors and agricultural machinery, the use of rubber tracks for combine harvesters, rubber impervious layers and rubber dams for irrigation pools, reservoirs, rubber boats, life-saving supplies, and other materials is increasing. Rubber accessories are available in agricultural by-product processing equipment, forestry, animal husbandry, and fishery technical equipment. For example, a Tieniu-40 wheeled tractor requires as many as 121 rubber products. With the rapid development of agricultural mechanization and farmland water conservancy, the demand for rubber products will increase.

4. Military and National Defense

Rubber is an important strategic material and is widely used in military and national defense. Military equipment, air force facilities, and national defense engineering all have rubber footprints. For example, a tank requires over 800 kilograms of rubber; A 30000 ton military ship requires 68 tons of rubber, and there are many types of ships, tents, warehouses, protective equipment, bathing clothes, and other products made of rubber. As for rubber products with special properties such as high temperature resistance, low temperature resistance, oil resistance, and high vacuum resistance required by cutting-edge defense technology, they are even more indispensable. With the development of national defense modernization, rubber that is required to be able to withstand temperatures ranging from - 100 to 400 ℃ and resist various acids, bases, and oxidants with special properties is being developed and produced.

5. Civil Construction

Machinery, transportation equipment, protective equipment, etc. used in construction have rubber products as accessories. For example, glass windows used in buildings are sealed with rubber strips, soundproof floors, acoustic sponges, rubber carpets, rainproof materials, and emulsion paints. Install large rubber spring seat cushions to reduce vibration and noise caused by subways, and mitigate earthquake damage to buildings. Mixing latex with cement can improve the elasticity and wear resistance of cement. Adding 3% rubber or latex to asphalt to pave road surfaces can prevent cracking and improve impact resistance.

6. Electrical communication

Another characteristic of rubber is its good insulation performance and its difficulty in conducting electricity. Various wires and cables are mostly made of rubber. Hard rubber is also commonly used to make rubber tubes, rubber rods, rubber plates, partitions, and battery shells. In addition, it is widely used as protective equipment, insulating gloves, insulating rubber boots, shoes, etc.

7. Medical and health care

There are many rubber products used in the medical and health departments, such as various rubber hoses in hospitals, surgical gloves, ice bags, sponge cushions, and many other rubber products. Rubber products are also used as accessories for medical equipment and instruments. Medical rubber products often have special requirements, such as non-toxic, bactericidal, physiological inertia, radiation resistance, and so on. Butyl rubber has high biological inertia, chemical stability, and slight water permeability. It is used to process rubber bottle stoppers, ensuring the preservation of high moisture absorption, antibiotics, and anticancer agents. Great progress has been made in the manufacture of artificial organs and human tissue substitutes using silicone rubber. It is also used to make drug capsules, which are placed in appropriate positions in the body, to slowly and continuously release the drugs in the capsules, both improving the efficacy and being relatively safe.