The key difference between polyurea and polyaspartic is that polyurea has a ring structure, whereas polyaspartic has a chain-like structure.
All polyaspartic compounds are polyurea compounds, but not all polyurea are polyaspartic. Moreover, there are several other differences between polyurea and polyaspartic compounds.
CONTENTS
1. Overview and Key Difference
2. What is Polyurea
3. What is Polyaspartic
4. Polyurea vs Polyaspartic in Tabular Form
5. Summary – Polyurea vs Polyaspartic
What is Polyurea?
A polyurea is a form of elastomer derived from the reaction product of an isocyanate component and a synthetic resin blend. This preparation occurs through step-growth polymerization. The isocyanate can be aromatic or aliphatic in nature and can be a monomer, polymer, or any variant reaction of isocyanates, quasi-prepolymer, or prepolymer. This prepolymer of the quasi-polymer is made of an amine-terminated polymer resin or a hydroxyl-terminated polymer resin.
The term “polyurea” refers to “many urea.” Urea or carbamide is an organic compound having the chemical formula (NH2)2CO. This molecule has two -NH2 groups that are joined via a carbonyl functional group. Moreover, in polyurea, alternating monomer units of isocyanate and amines react with each other, forming urea linkages. In addition, urea can form from the reaction of isocyanates and water, which results in a carbamic acid intermediate.
The carbamic acid can immediately decompose by splitting off carbon dioxide, and it leaves behind an amine that can react with another isocyanate group, forming the polyurea linkage. This is a two-step reaction that is useful in making polyurethane foam. Carbon dioxide liberated in this reaction can be used primarily as a blowing agent in many polyurethane foams.
What is Polyaspartic?
Polyaspartic or poly aspartic ester is an organic compound made from the reaction between an amine and a dialkyl maleate via the aza-Michael reaction. It was first introduced in the early 1990s, making it a relatively new technology. In the production process, diethyl maleate is usually used as the dialkyl maleate. It introduces bulky groups to the molecule, which causes steric hindrance to slow down the reaction.
The resulting aspartic molecule is bigger in this stage, so a low amount of isocyanate is required to make up the weight-for-weight basis. Often, the isocyanate is the most expensive part of the system when the aliphatic isocyanate oligomer is useful. Therefore, it can result in an overall lower system cost per applied film thickness.
The patent for this material was issued to Bayer in Germany and Miles corporation in the USA. These products are useful in coatings, adhesives, sealants, and elastomers. Moreover, pure polyurea can react extremely quickly, which makes it almost unusable without plural component spray equipment. Furthermore, this technology uses a partially blocked amine to react more slowly with isocyanates; therefore, it produces a modified polyurea.
What is the Difference Between Polyurea and Polyaspartic?
Generally, all polyaspartic compounds belong to the group polyurea. Therefore, they have many similarities between them. But they have several differences between them as well. The key difference between polyurea and polyaspartic is that polyurea has a ring structure, whereas polyaspartic has a chain-like structure.
The below infographic presents the differences between polyurea and polyaspartic in tabular form for side-by-side comparison.
Summary – Polyurea vs Polyaspartic
A polyurea is a form of elastomer derived from the reaction product of an isocyanate component and a synthetic resin blend, while polyaspartic ester is an organic compound made from the reaction between an amine and a dialkyl maleate via the aza-Michael reaction. The key difference between polyurea and polyaspartic is that polyurea has a ring structure, whereas polyaspartic has a chain-like structure.
Reference:
1. Bacon, Troy. “What Are the Advantages of Polyaspartic Coatings?” ArmorThane, 6 July 2022.
Image Courtesy:
1. “Polyurea-components” By DMacks – Own work drawn in ChemDraw, based on en:File:Polyurea.jpg by en:User:Seanboeger (Public Domain) via Commons Wikimedia