Macromonomer

{{short description|Large molecule with an end-group enabling it to polymerize}}

{{Quote box

|title = IUPAC definition

|quote = Macromonomer molecule: A macromolecule that has one end-group which
enables it to act as a monomer molecule, contributing only a single monomeric unit
to a chain of the final macromolecule.{{cite journal|title=Glossary of basic terms in polymer science (IUPAC Recommendations 1996)|journal=Pure and Applied Chemistry|year=1996|volume=68|issue=12|pages=2287–2311|doi=10.1351/pac199668122287|url=http://pac.iupac.org/publications/pac/pdf/1996/pdf/6812x2287.pdf}}

}}

In polymer chemistry, a macromonomer (or macromer) is a macromolecule with one end-group that enables it to act as a reactive monomer and undergo further polymerization. Macromonomers will contribute a single repeat unit to a chain of the completed macromolecule.{{cite web|title=Macromonomer molecule|url=https://old.iupac.org/reports/1996/6812jenkins/molecules.html#1.9|work=Glossary of basic terms in polymer science|publisher=IUPAC|accessdate=25 April 2024}}{{cite web|title=Molecules and Molecular Structure|url=http://old.iupac.org/reports/1996/6812jenkins/molecules.html|accessdate=12 October 2010}}{{cite book |last1=Fried |first1=Joel R. |title=Polymer Science & Technology |date=2003 |publisher=Prentice Hall |isbn=0-13-018168-4 |page=69 |edition=2nd}}

Several macromonomers have been successfully synthesized utilizing various methods such as controlled radical polymerization (CRP){{Cite web |date=August 3, 2015 |title=Importance of Macromonomer Quality in the Ring-Opening Metathesis Polymerization of Macromonomers |url=https://pubs-acs.org/doi/full/10.1021/acs.macromol.5b01176 |website=ACS Publications |doi=10.1021/acs.macromol.5b01176}} and copper-catalyzed "click" coupling.{{Cite web |date=April 20, 2009 |title=Efficient Synthesis of Narrowly Dispersed Brush Polymers via Living Ring-Opening Metathesis Polymerization of Macromonomers |url=https://pubs-acs.org/doi/10.1021/ma900280c |website=ACS Publications |doi=10.1021/ma900280c}}

Due to the larger size of macromonomers (as opposed to the size of regular monomers), synthetic challenges are brought about, giving reason for the analysis of polymerization mechanisms. Recent studies have shown that macromonomer polymerization kinetics and mechanisms can be significantly affected by the topological effect.{{Cite web |date=June 21, 2021 |title=Topological Effect on Macromonomer Polymerization |url=https://pubs-acs.org/doi/full/10.1021/acs.macromol.1c00256 |website=ACS Publications |doi=10.1021/acs.macromol.1c00256}}

Macromonomers are also used in controlled graft copolymerization.