Resin is a general term for high molecular weight compounds that soften and have plasticity when exposed to heat. It is generally an amorphous solid or semi-solid and can be divided into two categories: natural resins and synthetic resins. It has a wide range of applications in various fields such as industry and daily life.
classification
Classified by source: can be divided into natural resins and synthetic resins. Natural resin refers to amorphous organic substances obtained from the secretions of animals and plants in nature, such as rosin, amber, and cordyceps. Synthetic resin refers to the product obtained by chemical synthesis of simple organic compounds or chemical reactions of certain natural products, such as phenolic resin, polyvinyl chloride resin, etc. Among them, synthetic resin is the main component of plastics.
Classified by synthetic reactions: can be divided into adducts and condensates. Additive polymers refer to polymers produced by addition polymerization reactions, such as polyethylene, polystyrene, and polytetrafluoroethylene. Polycondensates refer to polymers produced by condensation polymerization reactions, such as phenolic resins, polyester resins, and polyamide resins.
According to the composition of the molecular main chain, it can be classified into carbon chain polymers, heterocyclic polymers, and elemental organic polymers. Carbon chain polymer refers to a polymer whose main chain is composed entirely of carbon atoms, such as polyethylene and polystyrene. Heterocyclic polymer refers to a polymer whose main chain is composed of atoms of two or more elements such as carbon, oxygen, nitrogen, and sulfur, such as polyoxymethylene, polyamide, polysulfone, and polyether. Elemental organic polymers refer to those that do not necessarily contain carbon atoms on the main chain, but are mainly composed of atoms of elements such as silicon, oxygen, aluminum, titanium, boron, sulfur, phosphorus, etc., such as organosilicon.
According to the changes after heating, it can be classified into thermoplastic resin and thermosetting resin. Thermoplastic resin is a type of resin that solidifies after heating, solidifies after cooling, and softens after heating. It can be molded multiple times and has solubility/melting properties, such as polyethylene, polyvinyl chloride, etc. Thermosetting resins become insoluble/melted solidified products after hot pressing, and do not soften even when heated, meaning they can only be molded once, such as phenolic resins, epoxy resins, etc.
Polyethylene can be used for the production of insulation layers in power cables after cross-linking modification; Phenolic resin is commonly used in the production of insulation partitions, low-voltage knife switch housings, etc. due to its high temperature resistance; Epoxy resin has good electrical insulation performance and can be used to make electrical equipment such as dry-type transformers and dry-type transformers; Resin has excellent comprehensive properties and is widely used in industrial fields such as machinery, automobiles, electronics, and electrical appliances.