樹脂

樹脂有天然樹脂和合成樹脂之分。天然樹脂是指由自然界中動植物分泌物所得的無定形有機物質，如松香、琥珀、蟲膠等。合成樹脂是指由簡單有機物經化學合成或某些天然產物經化學反應而得到的樹脂產物，如酚醛樹脂、聚氯乙烯樹脂等，其中合成樹脂是塑料的主要成分。

按合成反應

按此方法可將樹脂分為加聚物和縮聚物。加聚物是指由加成聚合反應制得的聚合物，其鏈節結構的化學式與單體的分子式相同，如聚乙烯、聚苯乙烯、聚四氟乙烯等。

縮聚物是指由縮合聚合反應制得的聚合物，其結構單元的化學式與單體的分子式不同，如酚醛樹脂、聚酯樹脂、聚酰胺樹脂等。

Resins are made from natural resins and synthetic resins. Natural resins are amorphous organic substances, such as rosin, amber and shellac, obtained from the secretions of plants and animals in nature. Synthetic resin is to point to by some simple organic compounds by chemical synthesis or natural products by the reaction of a chemical resin products, such as phenolic resin, PVC resin, etc., the plastic is the main component of synthetic resin.

Synthetic reaction

According to this method, the resin can be divided into addition polymer and condensation polymer. A polymer is a polymer produced by addition polymerization. The chemical formula of its chain structure is the same as that of a monomer, such as polyethylene, polystyrene and polytetrafluoroethylene.

Polycondensation is a kind of polymer produced by condensation polymerization. The chemical formula of its structural unit is different from that of the monomer, such as phenolic resin, polyester resin and polyamide resin.