Britannica
Sources used in this answer
How do linear, branched, and network polymer structures differ?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
major industrial polymers
Figure 1: The linear form of polyethylene, known as high-density polyethylene (HDPE).
Polymer structures are categorized based on how their monomer units are linked, which significantly influences their physical properties and industrial applications.12
- Linear Polymers: These consist of monomers joined end-to-end to form long, chainlike molecules. Because these chains can pack together closely, they are held by strong intermolecular forces, making them tough and suitable for items like bottles or toys. They are typically thermoplastic, meaning they soften when heated and can dissolve in solvents.123
- Branched Polymers: These feature shorter chains that grow off the main polymer backbone. This branching prevents the molecules from packing as closely as linear chains, resulting in weaker intermolecular forces. Consequently, these polymers are often more flexible, such as low-density polyethylene used in packaging film.21
- Network Polymers: These are formed when numerous branches cross-link to other chains, creating a complex, three-dimensional structure. Their properties depend on network density: dense networks are rigid or brittle, while those with fewer connections can be elastic. Unlike linear or branched polymers, they do not melt without decomposing and generally do not dissolve.12