Synthetic resin is a polymer compound, which is produced by combining low molecular raw materials – monomers (such as ethylene, propylene, vinyl chloride, etc.) into macromolecules through polymerization. Polymerization methods commonly used in industry include bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, slurry polymerization, gas phase polymerization, etc. The raw materials for the production of synthetic resins are abundant. In the early days, they were mainly coal tar products and calcium carbide calcium carbide. Now they are mostly oil and natural gas products, such as ethylene, propylene, benzene, formaldehyde and urea.
Ontology aggregation
Bulk polymerization is a polymerization process in which monomers are polymerized under the action of initiators or heat, light, and radiation without adding other media. The characteristic is that the product is pure, no complicated separation and purification are required, the operation is relatively simple, and the utilization rate of production equipment is high. It can directly produce high-quality products such as pipes and plates, so it is also called block polymerization. The disadvantage is that the viscosity of the material increases continuously with the progress of the polymerization reaction, the mixing and heat transfer are difficult, and the temperature of the reactor is not easy to control. The bulk polymerization method is often used in the production of resins such as polyadditional methyl acrylate (commonly known as plexiglass), polystyrene, low-density polyethylene, polypropylene, polyester and polyamide.
suspension polymerization
Suspension polymerization refers to the polymerization process in which the monomer is dispersed into droplets under the action of mechanical stirring or vibration and a dispersant, and is usually suspended in water, so it is also called bead polymerization. The characteristics are: there is a large amount of water in the reactor, the viscosity of the material is low, and it is easy to transfer heat and control; after polymerization, it only needs to go through simple separation, washing, drying and other processes to obtain a resin product, which can be directly used for molding processing; the product is relatively pure , evenly. The disadvantage is that the production capacity of the reactor and the purity of the product are not as good as the bulk polymerization method, and the continuous method cannot be used for production. Suspension polymerization is widely used in industry.
Post time: Nov-19-2022