Difference Between Polyurethane & Urethane

There are a number of chemicals that are used in various construction products in varying trades. Sometimes it can be confusing when two similar chemicals are part of the overall makeup of a product--such as urethane and polyurethane. Knowing their differences can help an individual make a more educated choice when purchasing various products for home and office projects.

Basics

At its most basic level, polyurethane is nothing more than a polymer, which is “a chemical compound or mixture of compounds formed by polymerization and consisting essentially of repeating structural units," according to Merriam Webster Dictionary. These repeating units are urethane, which is a chemical group comprised of a specific group of atoms--including two oxygen, one nitrogen, one carbon, and one hydrogen atom--arranged in a specific pattern. Technically, urethane is just a chemical group and polyurethane is a material than incorporates many urethane groups, according to Advanced Urethane.

Function

The purpose of urethanes--or more specifically, polyurethanes--is to help create materials used in a wide variety of household and commercial uses that are far stronger than their base components. Specifically, polyurethanes are used when creating ultra-durable, long-term use products that can adapt to a wide variety of circumstances, such as extreme heat or extreme cold. Since it is a chemical mixture of urethanes and other components, polyurethanes can be adapted to almost any situation.

Use

Polyurethane products are used in literally thousands of applications. Polyurethane can be used in low-density foam products such as upholstery or padding of automobile seats or as elastomers used in shoes for the padding. It can also be used for seals and gaskets and to help form hard plastics, which are more durable than regular plastic or synthetic rubber. In the home, polyurethane is most commonly found in a varnish or sealer for hardwood floors, cabinets and other wood surfaces because it creates a tough coat over the wood to protect it from scratching and moisture.

Misconception

There is not much difference between a urethane product and a polyurethane product. While the overall chemical structure of products might vary depending if they are used for padding, plastics, varnish or one of the many other hundreds of things, they all contain urethanes. The term “poly” simply means that there are multiple urethanes in a product, and came about in the past due to the fact that the primary chemical group within the polymers was urethane. The term "polyurethane" can be somewhat misleading given the fact that it basically means nothing more than a chemical group which has a number of urethanes within it, but can differ in terms of specific properties.

Durability

The main difference in polyurethane products and urethane products is in the number of urethanes within the actual product itself. Polyurethane is created at the intermolecular level, and the old saying about a chain being strong because of its multiple links, holds the same here. In short, polyurethanes are far more durable and can be molded into a wider degree of applications than urethane can, leading to harder, stronger and longer-lasting products depending on how many urethanes are added, and what specific products a manufacturer desires.