What is the Difference Between IPN and Blend

The key difference between IPN and blend is that IPN contains two polymeric components that are both crosslinked, whereas blend contains two or more polymers that are mixed together.

The term IPN stands for interpenetrating polymer networks. A polymer blend or a polymer mixture is a member of a class of substances that are analogous to metal alloys.

1. Overview and Key Difference
2. What is IPN
3. What is Blend
4. IPN vs Blend in Tabular Form
5. Summary – IPN vs Blend

What is IPN?

The term IPN stands for interpenetrating polymer network. It is a polymer consisting of two or more networks that are at least partially interlaced on the polymer scale, but they are not covalently bonded to each other. We cannot separate networks without breaking the chemical bonds. There can be two or more networks that can be described as entangling in such a way that the networks are concatenated and cannot be drawn apart. Moreover, the networks cannot be pulled apart; however, they are not bound to each other through any chemical bond.

Figure 01: The Structure of a Cadmium Cyanide Sample

Generally, the mixing of two or more polymers cannot create an IPN. Moreover, an IPN cannot be formed from a polymer network containing one type of monomers that are bound to each other forming one network such as heteropolymer of copolymer. Furthermore, there can be some semi-interpenetrating polymer networks that are abbreviated as SIPN. There can also be pseudo-interpenetrating polymer networks known as PIPN. Typically, when creating IPNs or SIPNs, we can observe the formation of different components simultaneously or sequentially.

When considering the important properties of IPN, the molecular intermixing can increase the glass transition regions in the IPN material when compared to component polymers. This is a unique characteristic that can provide the material an excellent mechanical damping properties at a wide range of temperatures and frequencies.

What is Blend?

A polymer blend or a polymer mixture is a member of a class of substances that are analogous to metal alloys. In polymer blends, at least two polymers are mixed together to create a new material consisting of different physical properties.

Figure 02: Formation of a Polymer Blend

There are three broad categories of polymer blends: immiscible polymer blends, compatible polymer blends, and miscible polymer blends. Using the term polymer alloy for this type of material is not suitable because polymer alloys include multiphase copolymers, which exclude incompatible polymer blends.

Some common examples for polymer blends include homopolymers such as polyphenyl oxide and polyethylene terephthalate and copolymers such as polypropylene and polycarbonate. We can use these polymer blends as thermoplastic elastomers. When considering the history of polymer blend preparation, the first preparation and modification technique for this substance was polymerization.

What is the Difference Between IPN and Blend?

The term IPN stands for interpenetrating polymer network. A polymer blend or a polymer mixture is a member of a class of substances that are analogous to metal alloys. The key difference between IPN and blend is that IPN contains two polymeric components that are both crosslinked, whereas blend contains two or more polymers that are mixed together.

Below is a summary of the difference between IPN and blend in tabular form for side by side comparison.

Summary – IPN vs Blend

IPN and polymer blends are important terms in polymer chemistry. The key difference between IPN and blend is that IPN contains two polymeric components that are both crosslinked, whereas blend contains two or more polymers that are mixed together.

Reference:

1. “Examples Of Ipns“. Pslc.Ws, 2022.

Image Courtesy:

1. “Cd(CN)2” By Smokefoot – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Blending (Ch-ABS)” By Vicente Neto – Own work (CC BY 4.0) via Commons Wikimedia