Natural rubber is considered a versatile rubber that can be used in the production of various rubber products due to its excellent mechanical and dynamic properties. However, NR rubber has major drawbacks, including poor resistance to heat, weather conditions, oils, and other chemicals. As a result, various types of synthetic rubber have become important alternatives to NR rubber. Nonetheless, some types of rubber products still require natural rubber as a raw material in the production process because:

1. NR rubber has excellent tensile strength even without the addition of reinforcing fillers and has very high elasticity, making it suitable for the production of certain products such as rubber gloves, condoms, balloons, and rubber bands.

2. NR rubber has good mechanical and dynamic properties, high elasticity, low heat buildup during use, and good tackiness, making it suitable for the production of various products such as truck tires, rubber dams, bumper guards, or as a blend with other synthetic rubbers to help improve other reinforcing efficiencies.

Properties of Natural Rubber (NR)
1. High tack (in the form of raw rubber or compound rubber)
2. High elasticity (Elastic), good resilience
3. High tensile strength
4. Good tear strength
5. Moderate abrasion resistance
6. Classified as unsaturated and non-polar rubber
6.1. Good resistance to polar chemicals
6.2. Poor resistance to petroleum oils or various non-polar solvents
6.3. Deteriorates quickly under high temperatures, sunlight, ozone, and oxygen

SBR rubber is a copolymer of styrene and butadiene produced through “Emulsion Polymerization,” and it was formerly known as Buna-S. SBR rubber is a general-purpose rubber similar to natural rubber and IR rubber, capable of being used in the production of a wide variety of products.
SBR rubber is a synthetic rubber that can be used for various applications and can serve as a substitute for natural rubber (except in cases requiring excellent dynamic properties). Therefore, this type of rubber is used in the production of belts, shoe soles, wire insulation, rubber hoses, and, importantly, is mostly used in the manufacturing of small vehicle tires, often in combination with other types of rubber.
Properties of SBR Rubber (Styrene-Butadiene Rubber)

1. Structure: Random copolymer
2. Composed of 23% Styrene and 77% Butadiene
3. Most widely used and significant synthetic rubber
4. Classified as unsaturated and non-polar rubber
5. Lower viscosity compared to natural rubber
6. Slightly higher abrasion resistance than natural rubber
7. Low tack
8. Lower tensile strength and tear resistance (requires the addition of reinforcing fillers)
9. Lower elasticity and resilience than natural rubber, leading to higher heat buildup
10. Not resistant to petroleum oils or various non-polar solvents
11. Deteriorates quickly under high temperatures, sunlight, ozone, and oxygen
12. Usable temperature range: -50°C to 100°C

EPDM rubber is known for its excellent resistance to heat, sunlight, oxygen, and ozone. EPDM rubber comes in various grades, differing in the proportions of ethylene and propylene as well as the amount of diene. Typically, this type of rubber contains ethylene ranging from 45-85% mol, but commonly available grades have ethylene content around 50-70% mol and diene content ranging from 3-11% mol. The proportions of ethylene and propylene directly impact the properties of the rubber; higher ethylene content results in higher strength in the uncured state, while lower ethylene content makes the rubber softer and more flexible.
EPDM rubber is widely used in automotive parts such as window seals, door seals, tire sidewalls, and radiator hoses. Additionally, EPDM rubber is used in the production of washing machine hoses, conveyor belts, waterproofing sheets, roofing membranes, and cable insulation.

Properties of Ethylene-Propylene Diene Terpolymer (EPDM)

1. Structure: Random copolymer of Ethylene, and Propylene => EPR or EPM
2. Classified as saturated and non-polar rubber
3. Excellent resistance to weathering, oxygen, ozone, sunlight, and heat
4. Poor resistance to non-polar solvents and oils (similar to natural rubber and SBR)
5. Higher elasticity than other synthetic rubbers but lower than natural rubber
6. Non-crystallizable, resulting in relatively low tensile strength (requires reinforcing fillers)
7. Good resistance to polar solvents: resistant to acids, bases, water, alcohols, hydraulic fluids, and oxygenated solvents
8. High specific electrical resistance, making it an excellent insulator, maintaining its insulating properties even at high temperatures
9. Usable temperature range: -40°C to 140°C

(Nitrile / Acrylonitrile-Butadiene Rubber)

NBR rubber, also known as nitrile rubber, has a high polarity, making it highly resistant to petroleum oils and various non-polar solvents. The properties of NBR rubber vary directly with the proportion of acrylonitrile content. Higher acrylonitrile content in NBR results in increased resistance to petroleum oils and hydrocarbon solvents, lower rebound, poorer compression set, reduced gas permeability, poorer low-temperature flexibility, improved heat and ozone resistance, higher abrasion resistance, increased tensile strength and durability, and higher density.

This type of rubber is primarily used in the production of oil-resistant rubber products that require good heat and abrasion resistance, such as oil gaskets, O-rings, seals, joint covers, conveyor belts, oil suction or delivery hoses, reinforced rubber hoses, tank linings, and roller coatings.

General Properties of NBR Rubber (Nitrile Rubber)

1. Structure: Copolymer of Butadiene and Acrylonitrile
2. Acrylonitrile (ACN) content: 18-51% by weight
3. Classified as unsaturated and polar rubber
4. Low tensile strength
5. High polarity (dependent on acrylonitrile content)
6. Excellent resistance to oils (vegetable oils, animal oils, and fuel oils), water, and non-polar solvents
7. Poor resistance to strong acids and polar liquids
8. Better heat resistance than natural rubber and SBR, but deteriorates under sunlight and ozone exposure (requires anti-degradation additives)
9. Non-crystallizable when stretched, resulting in low tensile strength
10. High abrasion resistance
11. Usable temperature range: -40°C to 120°C (dependent on acrylonitrile content)

(Hydrogenated Acrylonitrile-Butadiene Rubber)

HNBR rubber is known for its excellent resistance to degradation from heat (including hot water and steam), weathering, high-energy radiation, and ozone, which is comparable to EPDM. Additionally, it offers good resistance to oils.

HNBR properties generally fall between those of NBR and fluorocarbon rubber. Due to its higher cost, HNBR is typically used instead of NBR only in severe conditions or at high temperatures. It has the advantage over fluorocarbon rubber in terms of resistance to alkaline fillers, such as amine compounds. As a result, HNBR is commonly used for manufacturing rubber parts in oil drilling rigs.

General Properties of HNBR Rubber (Hydrogenated Acrylonitrile–Butadiene Rubber)

1. Excellent resistance to degradation caused by heat, hot oil, oxygen, ozone, various chemicals, sulfur-containing oils, and even hydrogen sulfide.
2. High tensile strength with good low-temperature flexibility.
3. High abrasion resistance, even under prolonged exposure to high temperatures.

(Chloroprene Rubber/ Neoprene Rubber)

CR rubber, commonly known as Neoprene, is known for its high tensile strength, excellent tear resistance, and good abrasion resistance. It is widely used in products requiring good mechanical properties, fire resistance, and resistance to oils, weathering, and ozone. Common applications of CR rubber include seals, reinforced hoses, roller coverings, mining conveyor belts, bumpers, linings, and construction products such as window seals, roof edges, bridge bearings, and outer cable sheaths.

General Properties of Chloroprene or Neoprene Rubber (CR)

1. Good mechanical properties due to strain-induced crystallization.
2. Classified as unsaturated and polar rubber (but less polar than NBR).
3. Moderate heat resistance.
4. Good resistance to non-polar solvents (but less than NBR).
5. Poor resistance to hydrocarbon solvents with chlorine.
6. Self-extinguishing properties: CR rubber extinguishes itself once the flame source is removed, unlike other rubbers that continue to burn after the flame source is removed.
7. Better resistance to weathering, heat, ozone, and sunlight compared to general diene rubbers.
8. Usable temperature range: -40°C to 100°C

(Chlorosulfonated Polyethylene Rubber/ Hypalon)

CSM rubber, commonly known as Hypalon, is renowned for its high resistance to heat, flames, ozone, weathering, chemicals, and high temperatures. It is widely used in applications requiring durability under harsh conditions, such as cable sheathing, hoses, roller coverings, linings, acid-resistant pipes, roofing membranes, and pool liners.

General Properties of CSM or Hypalon Rubber

1. High resistance to degradation from ozone and weathering due to its fully saturated polymer backbone. It also resists discoloration from sunlight and UV radiation.
2. Polar nature: Offers moderate to good resistance to oils (resistance increases with chlorine content) and excellent resistance to acids and corrosive chemicals. It also performs well in hot water applications.
3. Flame resistance: The material is self-extinguishing, meaning it will extinguish itself once the flame source is removed.
4. Usable temperature range: -10°C to 125-150°C

(150°C is feasible only for non-continuous high-temperature applications).

(Polyacrylate Rubber or Acrylic Rubber)

ACM rubber is known for its high polarity, which gives it excellent resistance to oils, heat, weathering, and ozone. Its properties are intermediate between NBR and FKM. ACM is often used in applications where both heat and oil resistance are required, such as in automotive parts like O-rings, oil seals, gaskets, and valve seals.

General Properties of ACM Rubber (Polyacrylate Rubber / Acrylic Rubber)

1. Excellent resistance to degradation from oxygen, ozone, and heat.
2. Softening at high temperatures: Once acrylic rubber is shaped, it tends to soften more significantly at elevated temperatures compared to general diene rubbers.
3. High polarity: This characteristic provides excellent resistance to oils at both room and high temperatures, although it is less resistant than FKM. ACM also withstands various additives often used in oils, making it increasingly used in place of NBR. However, it is not resistant to fuels.
4. Moderate resistance to water and chemicals: It performs less well in these areas compared to other types of rubber.
5. Usable temperature range: -10°C to 150°C

Silicone rubber is widely used across various industries due to its ability to withstand high temperatures and its non-toxic, clean properties. It is commonly found in the food and beverage industry, pharmaceuticals, and medical equipment, among other applications.

General Properties of Silicone Rubber (Q)

1. Variety of Types: Different types of silicone rubber vary based on the R groups attached to the main molecular chain.
2. Weather and Heat Resistance: Silicone rubber performs better than hydrocarbon-based rubbers in terms of resistance to weather, ozone, sunlight, and heat.
3. Temperature Tolerance: It remains effective over a wide temperature range, from very low to very high temperatures.
4. Low Compression Set: Silicone rubber exhibits a low compression set, meaning it maintains its shape after being compressed.
5. Moderate Oil Resistance: Similar to CR rubber, silicone rubber has moderate resistance to oils.
6. Resistance to Bacteria and Fungi: It is resistant to bacteria and fungi, making it suitable for medical and food applications.
7. Tissue Compatibility: Silicone rubber is biocompatible and well-tolerated by tissues.
8. Mechanical Properties: It has low tensile strength, tear resistance, and abrasion resistance, requiring reinforcement fillers for enhanced performance.
9. Chemical Resistance: It is not resistant to acids, bases, steam, and chemicals such as esters, ketones, and ethers.
10. Gas and Liquid Permeability: Silicone rubber has high permeability to gases and liquids, approximately 100 times more than butyl rubber.
11. Electrical Insulation: It offers the highest electrical insulation properties at room temperature compared to other rubbers and maintains these properties at temperatures up to 180°C.
12. Non-Stick Properties: Silicone rubber has a slippery surface and does not adhere to sticky surfaces or ice, making it useful for applications requiring non-stick properties or in refrigerators.
13. Temperature Range: Silicone rubber can be used in temperatures ranging from -100°C to 220-300°C, depending on the specific grade of silicone rubber.

(Fluorocarbon Rubber , FPM)

Fluorocarbon rubber is a type of copolymer with a high fluorine content. Fluorine not only imparts high polarity and stability to the rubber but also provides excellent resistance to aging due to weather, heat, oxidation, flames, and chemicals. This type of rubber is thus expensive and is commonly known by the trade name Viton, which comes in various grades depending on the chemical structure and fluorine content.

Fluorocarbon rubber can be used in the production of wire or cable insulation, especially where high resistance to heat, ozone, chemicals, and flames is required. Additionally, it can be used in the production of other products such as fuel hoses, O-rings, gaskets, and seals.

General Properties of Fluoroelastomer (FKM)

1. Fluorocarbon rubber, or Viton, is a saturated and polar rubber.
2. Fluorocarbon rubber, or Viton, has good resistance to heat and chemicals.
3. Fluorocarbon rubber, or Viton, has lower resistance to tensile stress, tear, and abrasion, so reinforcing fillers are often needed.
4. Fluorocarbon rubber, or Viton, has poorer mechanical properties compared to other diene rubbers and has relatively low elasticity.
5. Fluorocarbon rubber, or Viton, has the highest heat resistance among all types of rubber (except silicone rubber) and, due to its saturated bonds (no double bonds in the molecule), it is highly resistant to degradation caused by oxygen and ozone.
6. Fluorocarbon rubber, or Viton, can withstand swelling in hot oil, petroleum oil, fuel oil, chlorinated hydrocarbon solvents, acids, and various chemicals. However, it should not be used in the following chemical environments:

• Solvents such as ketones, ethers, and esters
• Low molecular weight organic acids like formic and acetic acids
• Hot water and steam
• Methanol
• Brake fluids containing glycol
• Hot hydrofluoric acid and chlorosulfonic acid
• Alkalis and amine compounds, as alkalis can cause the rubber to become hard, brittle, and prone to cracking, especially at high temperatures

1. Fluorocarbon rubber, or Viton, can resist degradation caused by high-energy radiation.
2. Fluorocarbon rubber, or Viton, maintains its elasticity even at high temperatures up to 200°C and can sometimes be used at temperatures up to 300°C (for short-term use). For low-temperature applications, it can be used at temperatures as low as -20°C.

Polyurethane rubber is often used in the production of products that require high weather resistance and excellent abrasion resistance and/or good resistance to solvents and oils. Examples of products made from polyurethane rubber include hoses, hose couplings, cable jackets, conveyor belts, caster wheels, shoe soles, seals, and gaskets.

General Properties of Polyurethane Rubber (PU)

1. Mechanical Properties: Polyurethane rubber (PU) exhibits superior mechanical properties including high resistance to tensile stress, tear, hardness, and abrasion compared to other types of rubber.
2. Weather Resistance: Polyurethane rubber (PU) has fewer double bonds in its molecules, which makes it more resistant to degradation caused by weather, oxygen, and ozone. However, it tends to degrade more easily in hot and humid conditions or when exposed to hot water, steam, acids, or alkalis.
3. Radiation Resistance: Polyurethane rubber (PU) has good resistance to degradation caused by high-energy radiation.
4. Chemical Resistance: Polyurethane rubber (PU) offers moderate to good resistance to oils, greases, and hydrocarbon solvents.
5. Temperature Range: Polyurethane rubber (PU) can be used in temperatures ranging from -35°C to 100°C (in dry conditions).