Monomer

Natural monomers

Amino acids are natural monomers that polymerize at ribosomes to form proteins. Nucleotides, monomers found in the cell nucleus, polymerize to form nucleic acids – DNA and RNA. Glucose monomers can polymerize to form starches, glycogen or cellulose; xylose monomers can polymerise to form xylan. In all these cases and is thus not pliable, a hydrogen atom and a hydroxyl (-OH) group are lost to form H₂O, and an oxygen atom links each monomer unit. Due to the formation of water as one of the products, these reactions are known as dehydration.

Isoprene is a natural monomer and polymerizes to form natural rubber, most often cis-1,4-polyisoprene, but also trans-1,4-polymer

Molecular weight

The lower molecular weight compounds built from monomers are also referred to as dimers, trimers, tetramers, pentamers, hexamers, heptamers, octamers, nonamers, decamers, dodecamers, eicosamers, etc. if they have 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, or 20 monomer units, respectively.^[6] Any number of these monomer units may be indicated by the appropriate Greek prefix. Larger numbers are often stated in English or numbers instead of Greek; e.g., a 20-mer is formed from 20 monomers. Molecules made of a small number of monomer units, up to a few dozen, are called oligomers.

Industrial use

Considering the current tight monomers market, particularly in propylene, and the benefits of membrane-based recovery processes, major polyolefin producers around the world already employ such recovery processes in new state-of-the-art plants. In order to enhance the competitiveness of older plants, the use of a recovery solution is becoming mandatory.^[7]

See also

• List of publications in polymer chemistry
• Prepolymer

Notes