Elastomers and historical background

To examine the historical background of elastomers, we must first examine the word rubber according to the first use of selected tires. Rub means to clean and purify. It means something like a cleanser. When rubber was invented in Europe in the 18th century, it was used to make shoelaces and rubber bands. They also tried to make it waterproof by adding various materials to the tires, but their performance was very poor. Because those tires changed their properties in the face of temperature changes.

In 1839, Charles Goodyear almost accidentally discovered vulcanization. This discovery, that is, the curing of rubber, made the rubber more stable in the face of changing environmental conditions and did not undergo fundamental changes.

What is an elastomer?

An elastomer is a large molecular material that can be stretched at least twice its original length at low temperatures under normal stress and return to its original shape and dimensions after the stress is released. Elastomers have the ability to bake or form cross-links, ie they are converted from a soft, viscous and soft heat material to a hard heat material. The curing process is usually performed by heating the elastomer mixture in the presence of sulfur or other crosslinking agents.

Types of elastomers:

  1. Natural elastomer
  2. Synthetic elastomer

Natural elastomers:

(Natural polyisoprene) NR Natural rubber

Advantages and features of natural polyisoprene:

  • Excellent jumping
  • High tensile strength
  • Superior resistance to tearing and abrasion
  • Good flexibility at low temperatures
  • Excellent adhesion to fibers and metals

Limitations of natural polyisoprene:

  • Poor resistance to heat
  • Low ozone resistance and sunlight
  • Very low resistance to oils and hydrocarbon solvents

Synthetic elastomers:

Polystyrene butadiene rubber (SBR)

Advantages and features of polystyrene butadiene rubber:

  • Excellent impact resistance
  • Good agility and tensile strength
  • Abrasion resistance and very good flexibility at low temperatures

Limitations of polystyrene butadiene rubber:

  • Low resistance to ozone and sunlight
  • Very low resistance to oils, gasoline and hydrocarbon solvents

Polybutadiene rubber (PBR)

Advantages and features of polybutadiene rubber:

  • Ultra high jump
  • Excellent flexibility at low temperatures
  • Excellent abrasion resistance
  • Shear growth and flexural cracking

Limitations of polybutadiene rubber:

  • Undesirable processability
  • Poor resistance to oil, gasoline and hydrocarbon solvents
  • Very low resistance to heat and ozone

Polyethylene propylene die monomers (EDPM)

Advantages and features of polyethylene propylene die monomers:

  • Excellent heat resistance
  • Ozone and sunlight
  • Good flexibility at low temperatures
  • Good resistance to acids and bases and oxygenated solvents
  • Excellent resistance to water and steam

Limitations of polyethylene propylene die monomers:

  • Poor resistance to oil and gasoline and hydrocarbon solvents
  • Poor adhesion to fibers and metals

Biotel (isobutylene, isoprene, IIR)

Advantages and features of Biotel:

  • Extraordinary impermeability and impermeability to gases and vapors
  • Very good resistance to heat, oxygen, ozone and sunlight
  • High energy absorption
  • Excellent resistance to water and steam

Biotel Limitations:

  • High compressive strength
  • Poor resistance to oil, gasoline and hydrocarbon solvents
  • Low elastic properties
  • Moderate processability and poor jumpability

Polychloroprene (CR) Neoprene:

Advantages and features of polychloroprene:

  • Good inherent flame resistance
  • Medium resistance to oil and gasoline
  • Excellent adhesion to fibers and metals
  • Very good resistance to ozone and natural aging
  • Good resistance to abrasion and flexural cracking
  • Very good resistance to bases and acids

Limitations of polychloroprene:

  • Poor resistance to oxygenated solvents
  • Aromatic flexibility at low temperatures

Nitrile, Acrylonitrile butadiene rubber (NBR):

Advantages and features of nitrile:

  • Very good resistance to oil and gasoline
  • Extraordinary resistance to hydraulic fluids with wide oil base
  • Good resistance to hydrocarbon solvents
  • Very good resistance to acids and bases

Nitrile Limitations:

  • Ozone and sunlight resistance and undesirable natural aging
  • Poor resistance to oxygenated solvents

Silicon rubber (Si, Q):

Benefits and features of silicone rubber:

  • Excellent flexibility at low temperatures
  • Low compressive strength (super heat resistance from 260-100 c)
  • Very good electrical insulation
  • Excellent resistance to weather, ozone, sunlight and oxidation stability
  • Excellent color retention

Limitations of silicone rubber:

  • Poor resistance to abrasion, tearing and cut growth
  • Low tensile strength
  • Unfavorable resistance to oils, gasoline and solvents
  • Poor resistance to acids and bases

Hypalon (CSM):

Advantages and features of Hypalon:

  • Good flame delay
  • Good abrasion resistance
  • Extraordinary resistance to weather, ozone, sunlight and oxidation
  • Excellent resistance to acids and bases
  • Very good color fastness and retention, medium strength

Polyurethane diisocyanate (EU, AU):

Advantages and features of polyurethane diisocyanate:

  • Extremely excellent wear and tear resistance
  • Very high tensile strength with good elongation
  • Excellent resistance to weather, ozone and sunlight
  • Good resistance to oil and gasoline
  • Excellent adhesion to fibers and metals

Limitations of polyurethane diisocyanate:

  • Poor resistance to acids and bases and oxygenated solvents
  • Unfavorable resistance to hot water

Types of polyurethane diisocyanate: based on ester and based on ether

Based on ester, they have excellent resistance to abrasion and heat, and based on ether, they have better flexibility at low temperatures.

Thioscol polysulfide (PTR, T):

Advantages and features of polysulfide:

  • Extremely excellent resistance to oils, gasoline and solvents
  • Good resistance to weather, ozone and sunlight
  • Excellent impermeability to gases and vapors

Polysulfide limitations:

  • Poor resistance to abrasion, tear, cut growth and flexural cracking
  • Low tensile strength
  • Very low compressive strength
  • Bad and unpleasant odor
  • Poor jumping

Acrylic polyacrylate (ACM)

Advantages and features of polyacrylate:

  • Extremely high resistance to heat and hot oil
  • Excellent resistance to weather, ozone and sunlight and oxidation
  • Very good resistance to gasoline and oil, especially those that contain sulfur

Limitations of polyacrylate:

  • Poor resistance to alcohols, bases, solvents and aromatic solvents
  • Limited flexibility at low temperatures
  • Unfavorable resistance to water and steam
  • Slow cooking song

Fluo and Carbon (FKM) Whiton

Advantages and features of fluorescent and carbon:

  • Excellent resistance to oil, gasoline, hydraulic fluids and hydrocarbon solvents (Excellent resistance to high temperatures up to 250 C)
  • Good delays in employment
  • Very good impermeability to gases and vapors
  • Very good resistance to weather, oxygen, ozone and sunlight

Limitations of fluoride and carbon:

  • Poor resistance to tearing and cut growth
  • Very low resistance to oxygenated solvents
  • Medium adhesion to fibers and metals

Epichlorohydrin (CO, ECO)

Advantages and features of epichlorohydrin:

  • Excellent resistance to oil and gasoline
  • Extraordinary impermeability to gases and vapors
  • Very good resistance to weather, ozone, sunlight and oxidation with a wide range of operating temperatures
  • Good resistance to petroleum-based fluids and solvents

Limitations of epichlorohydrin:

  • Unfavorable resistance to oxygenated solvents
  • Poor resistance to vapors and acids
  • Very low adhesion to fibers and metals

Chlorinated polyethylene (CM, CPE)

Advantages and features of chlorinated polyethylene:

  • Excellent resistance to alcohols, bases, acids
  • Very good resistance to weather, ozone, sunlight and oxidation
  • Good impermeability to gases and vapors
  • Excellent resistance to abrasion and flexural cracking
  • Stability and excellent color retention

Limitations of chlorinated polyethylene:

  • Weak to moderate resistance to aromatic and oxygenated solvents
  • Medium processability

Chemical cross-linked polyethylene (XLPE):

Advantages and features of polyethylene with chemical crosslinks:

  • Excellent resistance to alcohols, bases and acids
  • Excellent resistance to atmospheric conditions, ozone, sunlight and oxidation
  • Very good resistance to oils, gasoline and solvents

Limitations of polyethylene with chemical crosslinks:

  • Poor jumping and tear resistance
  • Abrasion resistance and unfavorable shear growth Poor adhesion to fibers and metals
  • Limited flexibility at low temperatures

Ethylene / acrylic (E / A) and wax

Advantages and properties of ethylene / acrylic:

  • Excellent resistance to heat, ozone, sunlight
  • Good tear resistance, flexural cracking and growth
  • Medium resistance to oil, gasoline and hydraulic fluids
  • High energy absorption

Ethylene / Acrylic Limitations:

  • Poor resistance to aromatic and oxygenated solvents
  • Limited flexibility at low temperatures
  • Unfavorable resistance to alcohols and acids

Ethylene-vinyl acetate (VAE) vinatene

Advantages and features of ethylene-vinyl acetate:

  • Excellent resistance to heat, ozone and sunlight and a wide range of operating temperatures
  • Medium resistance to oil and gasoline
  • Low compressive strength means good energy absorption
  • Excellent color fastness and retention

Limitations of ethylene-vinyl acetate:

  • Poor resistance to aromatic and oxygenated solvents
  • Medium processability

Polysorbourne (PNR) Nursork

Advantages and features of polyburnen:

  • High strength with low hardness
  • Wide range of energy absorption (dormancy)
  • Good resistance to abrasion and tearing
  • Very good impermeability to gases and vapors

Limits of polyburnen:

  • Poor resistance to ozone and sunlight
  • Very low resistance to oils, gasoline and hydrocarbon solvents

Application of elastomers:

Elastomers also have different applications due to their special properties. However, elastomers are generally used in the following cases:

  • Waterproof films, tapes and coatings
  • packing
  • Artificial leather
  • Washer
  • Pipe
  • hose
  • car tire
  • anti shock
  • Sealing and insulation
  • And many other applications

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