Commonly used Plasticizers in rubber products and their functions
The plasticizer is a commonly used additive in rubber products to improve the processing performance of rubber, which can reduce the force between rubber molecules, thereby reducing the glass transition temperature of rubber, increasing the plasticity and fluidity of rubber, and facilitating subsequent molding operations.
Plasticizers can also improve the mechanical properties of the vulcanize, improve the elasticity, lubricity, flexibility, etc. of the rubber compound.
Commonly used plasticizers are mainly divided into petroleum-based, coal tar-based, pine oil-based, and fatty oil-based plasticizers according to their sources.
- Petroleum plasticizers
Petroleum plasticizer is one of the most widely used plasticizers in the rubber industry, with a good plasticizing effect and low cost. The influence of petroleum-based plasticizers on the properties and performance of rubber compounds depends on their composition and properties. Commonly used are paraffin oil, aromatic oil, naphthenic oil, mechanical oil, petrolatum, and so on.
Paraffin oil is less polluting, can be used in light-colored rubber products, and has little effect on the mechanical properties of rubber compounds, and is more effective in ethylene-propylene reclaimed rubber products and butyl reclaimed rubber products.
Aromatic oil has good compatibility with rubber and is not suitable for spraying, and its processing performance is better than that of paraffin oil HY12S10J2L and naphthenic oil. Commonly used in dark rubber products.
Vaseline used as a rubber plasticizer can make the rubber compound have good extrusion performance, improve the adhesion between rubber and metal, less pollution, and also act as a physical anti-aging agent, which can affect the hardness and tensile strength of the rubber compound.
- Coal tar plasticizer
Coal tar series plasticizers have good compatibility with rubber and can improve the aging resistance of rubber, but have an inhibitory effect on accelerators, affect vulcanization, and have high brittleness temperature. Commonly used are coal tar, and coumarone resin.
Solid coumarone has good compatibility with rubber, which can improve the process performance of rubber compound extrusion, calender adhesion, and so on. The dosage of solid coumarone is 3-6 parts, which can dissolve sulfur, help the dispersion of sulfur and carbon black, and prevent scorch. Cumalon with a high softening point has better reinforcement and improves the mechanical properties and aging resistance of the vulcanizate, but it has an impact on the flexibility of the vulcanizate. It is an organic reinforcing agent in nitrile reclaimed rubber products, which can improve tensile strength and elongation. The plasticity and viscosity of liquid coumarone are better than that of solid coumarone, but the reinforcement is slightly worse. It can be used as a regeneration agent for reclaimed rubber.
- Pine oil plasticizer
Pine oil-based plasticizers can improve the adhesiveness of the rubber compound and help the dispersion of the compounding agent, but it has a delaying effect on vulcanization.
Pine tar helps to disperse the compounding agent in the rubber compound, has the effect of increasing the viscosity, and can improve the cold resistance of the product. It has the effect of delaying vulcanization and preventing scorch at low temperatures. This product is polluting and is not suitable for use in light-colored reclaimed rubber products.
Fatty oil plasticizers have low compatibility with rubber, and can only improve the lubricating effect, and the dosage is small.
There are many kinds of rubber products with different performance requirements. In actual production, the plasticizer can be reasonably selected according to the performance requirements of the product, and the plasticizer with good plasticizing effect, low dosage, fast absorption, and non-volatile and non-migrating plasticizer can be selected as far as possible. For environmentally friendly rubber products, colorless, odorless and non-polluting plasticizers should be selected.