Paper industry: 0.05-0.1%
Petroleum industry: 0.01-0.05%
Metal processing industry: 0.15-0.3%
Emulsion paint and coating industry: 0.2%
Electroplating and washing industry: 0.2-0.3%
Metalworking fluid crude oil plant: 0.00-0.5% 2-4%
Free radicals (because they can form large x conjugated systems, they are much more stable than free radicals (1), and are difficult to react with monomers, but can combine with active free radicals to terminate the chain reaction.
Inorganic compound type polymerization inhibitor
The inorganic compounds used as polymerization inhibitors mainly include ferric chloride, copper chloride, and titanium chloride. The mechanism of the first several kinds of polymerization inhibitors is essentially the use of chain addition or chain transfer, while ferric chloride and copper chloride play a role in inhibiting polymerization through charge transfer. Ferric chloride has high polymerization inhibition efficiency, anti wax additive and can eliminate free radicals in a stoichiometric ratio of 1:1, and can be used to determine the initiation rate.
In addition, an aqueous polymerization inhibitor will be used in suspension polymerization. It is mainly used to prevent the polymerization of monomers dissolved in the water phase. Common water phase polymerization inhibitors mainly include methine blue, nitroso R salt, water-soluble black, sodium sulfide, thiourea, sodium sulfate, ammonium thiocyanate, copper salts and certain phenols (trinitro Phenol, phenol) and so on. They can not only prevent the polymerization of monomers in water, but also reduce the solubility of monomers in water. Adding a small amount can reduce the water-phase polymer by more than 90%. However, the water phase polymerization inhibitor can also inhibit the monomer droplets. Larger dosages will prolong the polymerization reaction time. Therefore, the amount of water phase polymerization inhibitor is very small, usually (5~10)×10 -6 (based on water), the amount of sodium sulfide is large, up to (10~20)×10.
Leave a message
We’ll get back to you soon