The relative molecular weight is uncertain but usually high, and it appears as a solid, medium solid, pseudo solid, or sometimes liquid organic substance at room temperature. Has softening ormelting temperatureRange, with a tendency to flow under external forces, often ruptures in a shell like shape. Broadly speaking, it refers to materials used as plastic substratespolymerorprepolymerGenerally insoluble in water, soluble in organic solvents. According to the source, it can be divided intonatural resinandsynthetic resinAccording to their different processing behaviors, there are alsothermoplastic resinandthermosetting resinThe distinction.
By source
Resin can be divided into natural resin and synthetic resin. Natural resin refers to amorphous organic substances obtained from the secretions of animals and plants in nature, such asrosin、amber、shellacWait.synthetic resinIt refers to resin products obtained by chemical synthesis of simple organic compounds or chemical reactions of certain natural products, such asphenolic resin、PolyresinAmong them, synthetic resin is the main component of plastics.
According to the synthesis reaction
According to this method, the resin can be divided intoAdditive polymerandpolycondensateAdditive polymer refers to a polymer produced by addition polymerization reaction, whose chain structure has the same chemical formula as the molecular formula of the monomer, such aspolyethylene、polystyrene、PolytetrafluoroethyleneWait.
Polycondensates refer to substances composed ofcondensation polymerization The chemical formula of the structural unit of the polymer produced is different from the molecular formula of the monomer, such asphenolic resin、polyester resin、Polyamide resinWait.
