Intermediate Topic 781 of 1102 Organic Chemistry
Polymerization of Alkenes
Alkene monomers join to form long chains such as polyethylene.
In-depth explanation of Polymerization of Alkenes
Polymerization of alkenes is a chain-growth process in which many alkene monomers join together to form a long polymer chain without losing any atoms. The reaction can be initiated by free radicals, cations, anions or coordination catalysts, and each initiator opens the double bond so the monomers link end to end. The resulting addition polymers, such as polyethylene, polypropylene, polystyrene and PVC, have a carbon-only backbone and the same repeating unit as the monomer. Their properties depend on chain length, branching and the catalyst used.
Going deeper: Polymerization of Alkenes
Key ideas: Addition polymerisation of alkenes proceeds by radical, cationic or anionic chain growth, repeated n times to give a polymer with the same empirical formula as the monomer. Examples: ethene to polyethylene (LDPE at 1000 to 2000 atm with peroxide; HDPE with Ziegler-Natta catalyst at low pressure), propene to polypropylene, vinyl chloride to PVC, tetrafluoroethene to Teflon. Draw the repeat unit by opening the double bond.
Common mistakes and connections: Students keep the double bond in the repeat unit or forget the end bonds; the repeat unit has only single bonds. Another error is writing the polymer without brackets and n. Links to radical chains, Ziegler-Natta stereochemistry (isotactic polypropylene) and plastics recycling.
Visualization of Polymerization of Alkenes
Many alkene monomers add head to tail through their double bonds, forming a long saturated chain such as polyethylene. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Vinyl chloride, CH2=CHCl, polymerizes to poly(vinyl chloride), written as n CH2=CHCl giving the repeating unit -CH2-CHCl- n times.
Frequently asked questions about Polymerization of Alkenes
What is Polymerization of Alkenes?
Alkene monomers join to form long chains such as polyethylene.
Is Polymerization of Alkenes a beginner, intermediate or advanced topic?
Polymerization of Alkenes is a intermediate topic in Organic Chemistry. It builds on the vocabulary of beginner topics in this area.
What should I learn before Polymerization of Alkenes?
Study these earlier topics in Organic Chemistry first: Hydrogenation, Hydration of Alkenes, Ozonolysis.
What comes after Polymerization of Alkenes?
The next topics in Organic Chemistry are Electrophilic Aromatic Substitution and Nitration of Benzene.
Can I practise Polymerization of Alkenes with quizzes?
Yes. The interactive lesson includes a self-check question on Polymerization of Alkenes, and the Organic Chemistry quiz draws on every topic in this area.
Where Polymerization of Alkenes fits in Organic Chemistry
Polymerization of Alkenes is topic 53 of 148 in Organic Chemistry.