Polymerization Mechanisms: A Comprehensive Review of Step-Growth and Chain-Growth Pathways

Polymerization is a fundamental process in polymer science that underpins the synthesis of materials used across diverse industrial and technological sectors. This review provides a comprehensive examination of the two principal polymerization mechanisms—step-growth and chain-growth polymerization—highlighting their distinct reaction pathways, kinetics, and structural outcomes. In step-growth polymerization, monomeric units bearing complementary functional groups combine gradually, often producing small by-products, and requiring high monomer conversion to achieve high molecular weights. Conversely, chain-growth polymerization involves the rapid addition of monomers to an active centre, enabling the formation of high molecular weight polymers early in the reaction. The review explores subtypes such as radical, anionic, cationic, and coordination polymerizations, detailing their initiation, propagation, and termination steps. Special emphasis is placed on photo polymerization as a modern approach enabling spatial and temporal control in polymer synthesis, particularly in applications like 3D printing and micro fabrication. The comparative analysis also discusses the thermodynamic and kinetic considerations, reaction conditions, and practical applications of each method. Overall, this review aims to offer a consolidated understanding of polymerization mechanisms, serving as a valuable reference for students, researchers, and professionals involved in polymer chemistry and materials science.

Polymerization, Step-Growth Polymerization, Chain-Growth Polymerization, Radical Polymerization, Anionic Polymerization, Cationic Polymerization

1. Polymerization". The IUPAC Compendium of Chemical Terminology. 2014. doi: 10.1351/goldbook.P04740. [Google Scholar] [Crossref]

2. Young, Robert J. (1981). Introduction to polymers. London: Chapman and Hall. ISBN 0-412-22170-5. OCLC 8086791. [Google Scholar] [Crossref]

3. Clayden, Jonathan; Greeves, Nick; Warren, Stuart (2001). Organic chemistry. Oxford: Oxford University Press. pp. 1450–1466. ISBN 0-19-850347-4. OCLC 43338068. [Google Scholar] [Crossref]

4. Manas, Chanda (2023). Introduction to Polymer Science and Chemistry: A Problem-Solving Approach (2nd ed.). CRC Press (published 2013). ISBN 978-1-4665-5385-9. [Google Scholar] [Crossref]

5. Cowie, J. M. G. (2008). Polymers: chemistry and physics of modern materials. V. Arrighi (3rd ed.). Boca Raton: CRC Press. p. 4. ISBN 978-0-8493-9813-1. OCLC 82473191. [Google Scholar] [Crossref]

6. Allcock, H. R.; Lampe, Frederick Walter; Mark, James E. (2003). Contemporary polymer chemistry. Frederick Walter Lampe, James E. Mark (3rd ed.). Upper Saddle River, N.J.: Pearson/Prentice Hall. pp. 29–30. ISBN 0-13-065056-0. OCLC 51096012. [Google Scholar] [Crossref]

7. Fried, Joel R. (2003). Polymer science and technology (2nd ed.). Upper Saddle River, NJ: Prentice Hall Professional Technical Reference. p. 23. ISBN 0-13-018168-4. OCLC 51769096. [Google Scholar] [Crossref]

8. Jeremic, Dusan (2014). "Polyethylene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. pp. 1–42. doi:10.1002/14356007.a21_487.pub3. ISBN 9783527306732. [Google Scholar] [Crossref]

9. McKenzie, Thomas G.; Fu, Qiang; Wong, Edgar H. H.; Dunstan, Dave E.; Qiao, Greg G. (23 June 2015). "Visible Light Mediated Controlled Radical Polymerization in the Absence of Exogenous Radical Sources or Catalysts" (PDF). Macromolecules. 48 (12): 3864–3872. Bibcode:2015MaMol..48.3864M. doi:10.1021/acs.macromol.5b00965. ISSN 0024-9297. [Google Scholar] [Crossref]

10. Kaya, Kerem (January 2023). "A green and fast method for PEDOT: Photoinduced step-growth polymerization of EDOT". Reactive and Functional Polymers. 182: 105464. Bibcode:2023RFPol.18205464K. doi:10.1016/j.reactfunctpolym.2022.105464. [Google Scholar] [Crossref]

11. Soto, Marc; Sebastián, Rosa María; Marquet, Jordi (2014). "Photochemical Activation of Extremely Weak Nucleophiles: Highly Fluorinated Urethanes and Polyurethanes from Polyfluoro Alcohols". J. Org. Chem. 79 (11): 5019–5027. doi:10.1021/jo5005789. PMID 24820955. [Google Scholar] [Crossref]

12. Wang, Xifan; Schmidt, Franziska; Hanaor, Dorian; Kamm, Paul H.; Li, Shuang; Gurlo, Aleksander (May 2019). "Additive manufacturing of ceramics from preceramic polymers". Additive Manufacturing. 27: 80–90. arXiv:1905.02060. doi:10.1016/j.addma.2019.02.012. S2CID 104470679. [Google Scholar] [Crossref]

13. Mills, Benjamin; Grant-Jacob, James A; Feinaeugle, Matthias; Eason, Robert W (17 June 2013). "Single-pulse multiphoton polymerization of complex structures using a digital multimirror device" (PDF). Optics Express. 21 (12): 14853–8. Bibcode:2013OExpr.2114853M. doi:10.1364/oe.21.014853. ISSN 1094-4087. PMID 23787672. [Google Scholar] [Crossref]

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