I. Definition of resin
Resin usually refers to the range of softening or melting after being heated. When softened, it has a tendency to flow under the action of external forces. It is solid or semi-solid at room temperature, and sometimes it can be a liquid organic polymer. Broadly speaking, any polymer that can be used as a raw material for processing plastic products is called a resin.
Resin is divided into natural resin and synthetic resin. Natural resin refers to the amorphous organic substances obtained from animal and plant secretions in nature, such as rosin, amber, shellac, etc. Synthetic resin refers to a resin product obtained by chemical synthesis of simple organic matter or chemical reaction of certain natural products.
Second, the classification of resin
There are many ways to classify resins. In addition to dividing them into natural resins and synthetic resins according to the source of the resin, they can also be classified according to the synthesis reaction and main chain composition.
1. Classification by resin synthesis reaction
According to this method, the resin can be divided into addition polymer and condensation polymer. The addition polymer refers to a polymer prepared by addition polymerization, and the chemical formula of its link structure is the same as the molecular formula of the monomer, such as polyethylene, polystyrene, and polytetrafluoroethylene.
Condensation polymer refers to a polymer made by condensation polymerization. The chemical formula of its structural unit is different from the molecular formula of monomer, such as phenol resin, polyester resin, polyamide resin, etc.