What is the Difference Between Isobutylene and Polyisobutylene

The key difference between isobutylene and polyisobutylene is that isobutylene is a monomer, whereas polyisobutylene is a polymer.

Isobutylene or 1-butene is an organic compound having the chemical formula CH3CH2CH=CH2. Polyisobutylene or polyisobutene is a type of organic polymer that is made from the polymerization of isobutene. Moreover, isobutylene appears as separate, individual molecules while polyisobutylene molecules contain lots of isobutylene molecules connected to each other.

CONTENTS

1. Overview and Key Difference
2. What is Isobutylene  
3. What is Polyisobutylene
4. Similarities – Isobutylene and Polyisobutylene
5. Isobutylene vs Polyisobutylene in Tabular Form
6. Summary – Isobutylene vs Polyisobutylene

What is Isobutylene?

Isobutylene or 1-butene is an organic compound having the chemical formula CH3CH2CH=CH2. It is also known as 1-butylene. It appears as a colorless gas that can be made into a colorless liquid. We can classify this substance as a linear alpha-olefin. More importantly, isobutylene is a flammable gas.

We can produce 1-butene via the separation from crude C4 refinery streams and through ethylene dimerization. Separation from the C4 refinery creates a mixture of 1- and 2- butane compounds. The ethylene dimerization process produces only the terminal alkene. We can distill the product given by these methods to get a very high purity product. Approximately about 12 billion kilograms of 1-butene were produced in 2011.

This substance is useful for the production of a variety of products. For example, we can alkylate isobutylene with butane which gives isooctane. Or else, we can dimerize it to get diisobutylene which then can be hydrogenated to get isooctane. Isooctane is important as a fuel additive. Moreover, isobutylene is useful in producing methacrolein. Besides, we can get butyl rubber through the polymerization of isobutylene. Furthermore, alkylation of phenols with isobutylene via Friedel-Crafts alkylation gives antioxidants such as butylated hydrxytoluene and butylated hydroxyanisole.

What is Polyisobutylene?

Polyisobutylene or polyisobutene is a type of organic polymer that is made from the polymerization of isobutene. Typically, these substances exist as colorless gummy solids.

The polymerization process of isobutylene is initiated with a strong Bronsted or Lewis acid. The resulting polymer has a molecular weight that determines the applications of the polymer material. Besides, the low molecular weight polymer material is a mixture of oligomers. It is useful as a plasticizer. Moreover, there are medium and high molecular weight polyisobutylene that are important as components of commercial adhesives.

What are the Similarities Between Isobutylene and Polyisobutylene?

1. Isobutylene and polyisobutylene are organic compounds.
2. Both compounds contain four-carbon units.
3. Moreover, they are very important in industries.
4. In addition, both isobutylene and polyisobutylene appear as colorless liquid substances.

What is the Difference Between Isobutylene and Polyisobutylene?

Isobutylene or 1-butene is an organic compound having the chemical formula CH3CH2CH=CH2. Polyisobutylene or polyisobutene is a type of organic polymer that is made from the polymerization of isobutene. The key difference between isobutylene and polyisobutylene is that isobutylene is a monomer, whereas polyisobutylene is a polymer. In addition, isobutylene substance appears as separate, individual molecules, while polyisobutylene molecules contain lots of isobutylene molecules connected to each other.

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

Summary – Isobutylene vs Polyisobutylene

Isobutylene or 1-butene is an organic compound having the chemical formula CH3CH2CH=CH2. Polyisobutylene or polyisobutene is a type of organic polymer that is made from the polymerization of isobutene. The key difference between isobutylene and polyisobutylene is that isobutylene is a monomer, whereas polyisobutylene is a polymer.

Reference:

1. “Polyisobutylene.” An Overview | ScienceDirect Topics.
2. “Polyisobutylene.” Polysciences, Inc.

Image Courtesy:

1. “Isobutylene-2D-skeletal” By Ben Mills – Own work (Public Domain) via Commons Wikimedia
2. “Polyisobutylene” By Polimerek – Own work (Public Domain) via Commons Wikimedia