Accelerators:

 By far the most common vulcanizing methods depend on sulfur. Sulfur, by itself, is a slow vulcanizing agent and does not vulcanize synthetic polyolefin s. Even with natural rubber, large amounts of sulfur, as well as high temperatures and long heating periods are necessary and one obtains unsatisfactory crosslinking efficiency with unsatisfactory strength and aging properties. Only with vulcanization accelerators can the quality corresponding to today's level of technology be achieved.
Types of accelerators include:

• CBS(CZ)
• DETU
• DOTG
• DPG
• DPTU
• ETU
• MBS
• MBT

• MBTS
• MDB
• PEP
• PPC
• PTA
• TBBS(NZ)
• TBZTD

• TDEC
• TETD
• TIBTD
• TMTD
• TMTM
• ZBEC
• ZDBC

• ZDEC(LDA)
• ZDMC

Activators

These materials form a complex with the accelerator, then increase the curing rate and improve the properties of the final product, the maximum utilization of accelerator systems experience.
These materials raise efficiency with active accelerators. Activators and accelerators can be divided into three categories:

• Mineral materials: metal oxides

  • Zinc oxide

  • Red Lead oxide

  • Magnesium Oxide

  • Lytarzh

• Organic materials

  • Halogenated Stearic acid

  • Lauric acid

  • Stearic acid

  • Oleic acid

• Alkalis
  These substances increase the PH of rubber compounds and thus increase the curing rat.

  • DEA

  • Triethanolamine

Curing Agent

The most widely used and the most common curing agent is sulfur reacts with most unsaturated rubber and products vulcanized (network) of it.
A variety of methods exist for vulcanization. A typical vulcanization temperature for a passenger tire is 10 minutes at 170 °C. This process employs the technique known as compression molding. Other methods, for instance to make door profiles for cars, use hot air vulcanization or microwave heated vulcanization (both continuous processes).
Five types of curing systems are in common use. They are:

• Sulfur systems

• Peroxides

• Urethane crosslinkers

• Metallic oxides

• Acetoxysilane

Vulcanization with sulfur

By far the most common vulcanizing methods depend on sulfur. Sulfur, by itself, is a slow vulcanizing agent and does not vulcanize synthetic polyolefin s. Even with natural rubber, large amounts of sulfur, as well as high temperatures and long heating periods are necessary and one obtains unsatisfactory crosslinking efficiency with unsatisfactory strength and aging properties. Only with vulcanization accelerators can the quality corresponding to today's level of technology be achieved.

Metal oxides

Carboxyl rubber, butadiene rubber, and nitrile rubber can react with the carboxyl groups to form cross-links with the process of neutralization of carboxyl groups and the formation of salts done. Poly chloroprene (neoprene), also by reaction with metal oxides such as zinc oxide can be vulcanized. In most systems, metal oxides are used to control the curing rate and absorption of resulting chloride.

Functional material

Substances that react with the polymer chain, bridge, and with this type of crosslinking, form a three-dimensional network. Epoxy-resin with rubber Nitrile, Dioxime with Butyl rubber and Diamine, or Disulfide with fluorocarbon rubber is used and form three-dimensional bonds.

Peroxide

Organic peroxide is used for vulcanization of saturated rubber or rubber without active groups to form cross-links. This curing agent doesn’t remain in polymer chain, but radical produces carbon bond formation in the polymer chain.

Fillers

Carbon black (subtypes are acetylene black, channel black, furnace black, lamp black and thermal black) is a material produced by the incomplete combustion of heavy petroleum products such as FCC tar, coal tar, ethylene cracking tar, and a small amount from vegetable oil. Carbon black is a form of paracrystalline carbon that has a high surface-area-to-volume ratio, albeit lower than that of activated carbon. It is dissimilar to soot in its much higher surface-area-to-volume ratio and significantly lower (negligible and non-bioavailable) PAH (polycyclic aromatic hydrocarbon) content. However, carbon black is widely used as a model compound for diesel soot for diesel oxidation experiments. Carbon black is mainly used as a reinforcing filler in tires and other rubber products. In plastics, paints, and inks carbon black is used as a color pigment.
The highest volume use of carbon black is as reinforcing filler in rubber products, especially tires. While a pure gum vulcanizate of styrene-butadiene has a tensile strength of no more than 2.5 MPa, and almost nonexistent abrasion resistance, compounding it with 50% of its weight of carbon black improves its tensile strength and wear resistance as shown in the below table. It is used often in the Aerospace industry in elastomers for aircraft vibration control components such as engine mounts.

Practically all rubber products where tensile and abrasion wear properties are crucial use carbon black, so they are black in color. Where physical properties are important but colors other than black are desired, such as white tennis shoes, precipitated or fumed silica has been used as a substitute for carbon black in reinforcing ability. Silica-based fillers are also gaining market share in automotive tires because they provide better trade-off for fuel efficiency and wet handling due to a lower rolling loss compared to carbon black-filled tires. Traditionally silica fillers had worse abrasion wear properties, but the technology has gradually improved to where they can match carbon black abrasion performance.