Monomers are generally unsaturated, cyclic, or low-molecular compounds containing two or more functional groups, and are a collective term for small molecules that can polymerize with the same or other molecules. It is a simple compound that can form a polymer compound by polymerization reaction or polycondensation reaction. It is a low-molecular raw material used in the synthesis of polymers. For example, vinyl chloride CH2=CHCl monomer can be polymerized to form polyvinyl chloride. Caprolactam monomers can be polymerized to form polycaprolactam. For example, ethylene, propylene, vinyl chloride, styrene, etc. are the monomers that synthesize polyethylene, polypropylene, polyvinyl chloride, and polystyrene. They are also the structural units that make up these four polymer compounds.
- Synthetic resin: A polymer compound prepared by polycondensation of monomers is conventionally named by adding the word "resin" after the name of the raw material, such as phenolic resin, epoxy resin, and urea-formaldehyde resin. The addition product is often called "resin" before it is made into a finished product, such as polyethylene resin and polypropylene resin.
Figure 1. Synthesis of phenolic resin.
- Synthetic polyamides: Polyamides are named after polyamides with a number indicating the quantity of carbon atoms in the monomer. For example, a polymer compound formed by polycondensation of hexamethylene diamine and adipic acid is called polyamide 66. The polymer compound formed by the polycondensation of decanediamine and sebacic acid is called polyamide 1010.
- Synthetic rubber: Monomers can also be used to synthesize rubber, which is named by adding several words that represent the name of the monomer before the word rubber. For example, the polymer of 1,3-butadiene and styrene is called styrene-butadiene rubber. The polymer of 2-chloro-1,3-butadiene is called neoprene. The polymer of butadiene and acrylonitrile is called nitrile rubber. The polymer of isoprene is called isoprene rubber.
- Synthetic nylon: Nylon polyamide synthetic fiber is also known as "nylon", such as nylon-6, nylon-66, and nylon-610. There are two or more numbers after the name, indicating that the polyamide fiber is polycondensation of two monomers, diamine, and dicarboxylic acid. The first figure is the number of carbon atoms of diamine, and the following figure is the number of carbon atoms of dicarboxylic acid. For example, nylon-610 is formed by polycondensation of hexane diamine and sebacic acid. There is only a number after the name, indicating that the polyamide fiber is polymerized from a certain number of carbon atoms of lactam. For example, nylon-6 is polymerized from caprolactam.
Figure 2. Synthesis of Nylon-66.
- Synthetic of polyester: Polyester, also known as polyester fiber, refers to the polymer compound formed by the connection of ester groups in the fiber molecules. At present, polyester poly (ethylene terephthalate), which has the largest output in industrial production, is synthesized from ethylene terephthalate.
- Synthetic of other kinds of polymer compounds: These monomers are often prepared by addition polymerization, and it is customary to add the word "polymer" before the name of the raw material. For example, the polymer synthesized by the vinyl chloride monomer is called polyvinyl chloride. The polymer synthesized by the tetrafluoroethylene monomer is called polytetrafluoroethylene. Plexiglass is a polymer prepared by addition polymerization of methyl methacrylate monomer, which is polymethyl methacrylate, also known as plexiglass.
Figure 3. Structural formula of polymethyl methacrylate.
- He Xiaoyu, Bao Yongzhong, Huang Zhiming, et al. (2004). “Synthesis and properties of in-situ polymerized polyvinyl chloride resin ” Chinese Plastics, 10:38.
- Yuan Huilin, Ma Peilan, Wang Jing, Li Jun, Guo Xian. (2004) “Properties and Application of Polyvinyl butyral Resin.“ Application of Engineering Plastics. 02:161-163