What are the ingredients in rubber compounds?

Ingredients in rubber compounds are a large group of components, including curing agents, accelerators and vulcanization activators, antioxidants, plasticizers, fillers and special additives (blowing agents, dyes, etc.). The list of ingredients in phr (parts per hundred rubber) called rubber compound recipe.

What is a rubber curing agent?

Most of the rubber products can also contain reinforcing materials – fibers, filaments, wires, metal. The most common curing agent is natural premium powdered sulfur in the form of yellow crystals of the orthorhombic form obtained during the processing of sulfur ores by grinding and sifting.

Why are organosilanes used in rubber vulcanization?

Therefore, organosilanes are used (organic silica compounds) to act as coupling agents between rubber and silica. However, Processing is more difficult because the chemical reaction must take place. Now time, temperature are crucial. Rubber Active Group – reacts with polymer during vulcanization and develops covalent filler-rubber bonds.

Why are organosilanes used as coupling agents between rubber and silica?

Hard clay at equal loadings to N-990 produces similar properties in Tensile, Tear and Abrasion but is deficient in Modulus and compression set. Therefore, organosilanes are used (organic silica compounds) to act as coupling agents between rubber and silica. However, Processing is more difficult because the chemical reaction must take place.

What color is rubber?

Coloring rubber in other colors is carried by the white tone. Iron oxide Fe2O3, often in conjunction with lithopone and sulfurous antimony, selenium, cadmium compounds, cinnabar mercury and sulfur are using as red pigments. Chromium oxide gives blue-green color, and blue – ultramarine.

What is a sulfur-cured rubber containing precipitated silica?

Sulfur-cured rubbers containing precipitated silica must be modified to obtain optimum performance. With fine particle silicas above about 20phr, diethylene glycol (DEG) or polyethylene glycol (DEG) reduces accelerator requirements. The glycols also buffer the variable moisture and are an economic advantage.