Neoprene is a popular elastomer used in many different applications. A part of the reason for neoprene’s versatility is the various ways in which manufacturing neoprene is done. Neoprene companies take many steps during the process of neoprene fabrication. Neoprene (commercial quality) can be made in many different forms. And each of these forms has a different name. Nonetheless, all types of neoprene are composed of polychloroprene, the name of the neoprene chemical formula. Polychloroprene, or neoprene, is a polymer of chloroprene. For our purposes, chloroprene is essentially what manufacturers of neoprene begin with when they produce neoprene products, such as liners (neoprene), neoprene spring rubber, and a neoprene mat. Neoprene rubber goes through a series of steps thereafter, all of which play a vital role in creating the final products that we know and love. But exactly how is neoprene made? In this article, we will cover the various forms in which sponge neoprene is offered. That way, our readers will get a better understanding of sponge neoprene, since its structures reveal much about how the material works and why it works the way it does. Toward the end, we will even discuss solid neoprene rubber, which will give you a better picture of the differences between solid neoprene and foamed neoprene. Along the way, we will answer the following questions:

• What is sponge neoprene rubber?
• What is sponge neoprene used for?
• Is sponge neoprene waterproof?
• What are the disadvantages of sponge neoprene?

To be transparent, neoprene is sometimes known by its chemical name, chloroprene (CR). This is why neoprene is so often referred to by any of the following names: chloroprene elastomer, chloroprene rubber, CR, CR rubber material, and chloroprene polymer. But wait. What is a chloroprene polymer? Well, neoprene is not technically just chloroprene. Chloroprene rubber products, or neoprene rubber products, are composed of many molecules of chloroprene bonded together. Thus, neoprene is more aptly dubbed polychloroprene by those in the neoprene industry. Poly- is a Greek prefix that symbolizes the meaning many. The term polychloroprene hence denotes the meaning many chloroprenes. Now, say you are asked: what is the monomer of polychloroprene? Nothing to fear. Mono- is the Greek prefix meaning one. If we plug this definition into the original question, then the answer is clear: the monomer of polychloroprene is chloroprene. Simple enough? We hope so. Keep this in mind as you continue learning about neoprene, for a deep understanding of the terminology involved in elastomers can be very revealing, as well as meaningful.

What Is Sponge Neoprene Rubber?

Sponge neoprene is one of the neoprene’s main forms. The neoprene material features gaseous pockets throughout its body, giving it a sponge-, or foam-like, structure. This is why sponge neoprene is also known as foam neoprene. These terms are interchangeable, referring to the same material. But there are different types of sponge neoprene, open-cell neoprene sponge and closed-cell neoprene sponge rubber. These types of sponge neoprene are markedly different, and their differences determine the applications for which each one is best suited.

What Is Sponge Neoprene Used For?

Sponge neoprene is used for applications such as a neoprene foam gasket material, neoprene foam insulation, a neoprene foam sheet (self-adhesive), and a neoprene foam adhesive. Open-cell sponge neoprene’s pockets of gas directly connect to the mat’s external environment, readily exchanging air and intaking other matter that can enter the mat through these openings. Thus, one of the main drawbacks of open-cell sponge neoprene is that it is not waterproof. Although neoprene itself is water-resistant, the structure of open-cell neoprene foam does not allow it to stop water from trespassing its barrier. By the same line, if air-tightness is one of your concerns when looking to buy neoprene material, veer away from open-cell neoprene sponge, as it will not be as effective as other types of neoprene at keeping air trapped in place. Despite this, open-cell neoprene sponge rubber has its place in the market. It is the best neoprene material for absorbing vibrations, especially sonic waves. In this vein, we can think of it as vibration-isolation neoprene. When sonic waves come into contact with open-cell, sheet rubber neoprene, the material readily intakes the vibrations. While this might sound counterintuitive, it is exactly the reason for why this type of sponge neoprene is unparalleled at absorbing noise. As we have mentioned, sponge neoprene is known for its internal network of individual chambers. As sonic waves traverse an open-cell neoprene mat, they bounce around within the sheet of neoprene, gradually weakening in force every time they ricochet off the neoprene pad’s interior walls. On the other hand, closed-cell neoprene sponge rubber, while it still possesses pockets of gas, these chambers stand as individual units—connected neither to each other nor to the mat’s exterior environment. This essentially makes closed-cell neoprene foam water- and air-tight, impermeable to water and air. Closed-cell neoprene sponge is especially efficient at thermal insulation. To better understand this, imagine that you are standing outside in extremely cold weather. Your goal is to maximize warmth, and you have the choice between two outfits. One choice is a single, thick jacket. The other is a composite of many, many jackets—layered over one another. If intuition has not told you already, then we will: the layered outfit will help you to better retain bodily heat. In the same way, closed-cell neoprene sponge retains heat better than a single roll of neoprene does. Its pockets of gas each act as a layer that traps heat, minimizing the rate at which heat leaves the object you are trying to insulate.

Is Sponge Neoprene Waterproof?

Sponge neoprene is technically waterproof, which means that it will not degrade when submerged. However, depending on the type of sponge neoprene you use, the material may still allow water to pass through its structure. As we have mentioned, open-cell neoprene foam has pores that connect to the material’s external environment, a quality which allows water to enter through the material. Thus, open-cell neoprene sponge, in essence, is not waterproof. But the material itself will not become damaged by water. However, closed-cell neoprene sponge rubber is indeed waterproof. Because its pockets of gas are each wholly enclosed, water will not be able to pass through the material. Thus, if your project requires a waterproof material, we recommend that you do not use open-cell neoprene sponge. If it demands sponge neoprene regardless, then opt for closed-cell neoprene foam—it will do a much better job at keeping water at bay.

What Are the Disadvantages of Sponge Neoprene?

One of the main disadvantages of sponge neoprene is its cost. Compared to other elastomers, neoprene is generally expensive. However, this is not to say that all neoprene is unaffordable. With recent developments in technology, scientists working with elastomers have developed blends of neoprene that have a significantly lower chloroprene rubber price. This sort of neoprene uses multiple elastomers, composing somewhat of a partial structure of neoprene. It is mixed with rubbers such as SBR, EPDM, and nitrile in order to abate the high costs associated with pure neoprene products. Nowadays, neoprene, cured of the high costs that burdened many previous versions of the material, is more affordable and accessible. At the end of the day, applications that require neoprene, such as neoprene pads for construction, find neoprene irreplaceable. This setback, although cumbersome, is sometimes unavoidable. Another disadvantage that sponge neoprene faces is that open-cell neoprene foam is vulnerable to permeation by water and air. But, this disadvantage is only a drawback if the application for which you buy neoprene rubber requires complete water- and air-tightness. If this is your situation, steer clear of open-cell neoprene products when you look to buy neoprene material. While sponge neoprene rubber is great for a wide range of different applications, it does not tend to last as long as its solid rubber counterpart. This is partly because solid rubber is meant to endure more physically demanding challenges. Although neoprene shelf-life, or longevity, is a part of all neoprene materials, solid neoprene rubber inherently lasts longer. Although the neoprene material properties are rather robust, the physical structure of a neoprene foam sheet is vulnerable to weakening over time. It can slowly lose its flexibility, among other things. In short, solid neoprene rubber has a good resistance to aging, whereas sponge neoprene does not.

As you can see, neoprene is available to you in many different forms. And can you believe it? That is not all! There are even different types of solid neoprene rubber! Hard and soft neoprene, although they may not sound very different, actually perform better or worse depending on the application to which they are applied. However, as a rule of thumb, the abrasion-resistance of neoprene is better in hard neoprene than it is in soft neoprene. In any case, when it comes to neoprene, your options are abundant. Remember that sponge neoprene and foam neoprene are the same thing, and that there are two types of sponge neoprene. Next time you are looking for neoprene materials, be sure to know which kind of neoprene you want!