Chain propagation
Encyclopedia
Chain propagation is a process in which a reactive intermediate
is continuously regenerated during the course of a chemical reaction
. In polymerization
reaction, the reactive end-group
s of a polymer chain react in each propagation step with a new monomer
molecule transferring the reactive group to that last unit.
Reactive intermediate
In chemistry a reactive intermediate is a short-lived, high energy, highly reactive molecule. When generated in a chemical reaction it will quickly convert into a more stable molecule. Only in exceptional cases can these compounds be isolated and stored, e.g. low temperatures, matrix isolation...
is continuously regenerated during the course of a chemical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
. In polymerization
Polymerization
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
reaction, the reactive end-group
End-group
An end-group in polymer chemistry is a constitutional unit that is an extremity of a macromolecule or oligomer molecule. For example the end-group of a PET polyester may be an alcohol group or a carboxylic acid group...
s of a polymer chain react in each propagation step with a new monomer
Monomer
A monomer is an atom or a small molecule that may bind chemically to other monomers to form a polymer; the term "monomeric protein" may also be used to describe one of the proteins making up a multiprotein complex...
molecule transferring the reactive group to that last unit.