Difference Between Acrylic and Plexiglass

Key Difference – Acrylic vs Plexiglass
 

The terms Acrylic and Plexiglass are often used interchangeably for plastic sheets made from a polymer derived from esters of methacrylic acid. The key difference between Acrylic and Plexiglass is that Plexiglass is a brand name of acrylic sheets. Acrylic latices may derive from esters of acrylic acid or methacrylic acid.  Acrylic elastomers have been considered as ‘specialty rubbers’ owing to their unique property, i.e., the presence of unsaturated polymer backbone, unlike in many other so-called general purpose rubbers. Because of that acrylic polymers can withstand high temperatures, UV, ozone, oxygen, etc. More details on acrylic and Plexiglass are discussed in this article.

CONTENTS

1. Overview and Key Difference
2. What is Acrylic
3. What is Plexiglass
4. Side by Side Comparison – Acrylic vs Plexiglass in Tabular Form
5. Summary

What is Acrylic?

Acrylic elastomers are specialty rubbers with an excellent set of properties such as resistance to high temperatures (> 150 °C), UV, ozone, oxygen, sulfur-bearing oils and greases, and dimension stability in aliphatic hydrocarbons. Most of the general purpose elastomers such as natural rubber, SBR, etc., do not possess such properties. Therefore, all these properties have made acrylics very useful in applications of automotive industry and manufacturing of oil cooler hoses, transmission seals, rear axle seals, etc. The monomer of acrylic elastomer has carbon-carbon backbone with a pendant carbalkoxy group and a α-hydrogen connected to alternate carbon atoms in the polymer chain.

The simplest acrylic elastomer is poly(ethyl acrylate), which has limited applications due to its low glass transition temperature (-15 °C). Acrylic latices are used in large quantities for certain applications such as binders for textile fibers and latex-based coatings. In addition, acrylic latices are used to make ion-exchange resins, for dispersions of pigments in paints or cement, and to aggregate suspended particles during waste water treatment processes.

Acrylic products are usually manufactured using either extrusion process or casting process. Extrusion method is much cheaper, but the process has certain disadvantages such as higher level of impurities and less hardness when compared to cast products.

What is Plexiglass?

Plexiglass is a brand of acrylic elastomer made out of poly(methyl methacrylate). The Plexiglass products are made by both extrusion and casting processes. Extruded products are less hard when compared to casted products; therefore, they are easy to process. However, the maximum service temperature of extruded Plexiglass is lower than that of cased Plexiglass products. When compared to standard acrylics, Plexiglass products are much costly owing to high purity and an excellent set of properties.

Plexiglass acrylics show excellent resistant to rain, stormy weather, extreme pressure, and heat. In addition, the sheets are break-resistant and come in clear and also in varied colors depending on their applications. The range of Plexiglass products is used as raw materials to manufacture aircraft cabin windows, computer monitors, and displays, structural glazing, noise barriers, automotive parts, etc. The products are available in corrugated sheets, films, molding compounds, multi-skin sheets, rods and tubes, solid sheets, and tubes.

What is the Difference Between Acrylic and Plexiglass?

Acrylic vs Plexiglass
Acrylic is a common name of an elastomer, whereas Plexiglass is a commercial name for the acrylic elastomer.	Standard acrylics are often manufactured by an extrusion method, which is low cost. Plexiglass sheets are made by both casting and extrusion process.

Summary – Acrylic vs Plexiglass

Acrylic and Plexiglass are referred to the same group of elastomers. An acrylic is a group of elastomers. Plexiglass is PMMA, which comes under the group of acrylic. Acrylic elastomers are known as specialty rubbers due to their excellent weather resistance, heat resistance, and solvent resistance. Thus, they are used in many application including in aircrafts parts, automotive parts, binders, resins, etc.

Reference:

1.Blackley, D. C. (2012). Polymer Latices: Science and Technology Volume 3: Applications of Latices. Springer Science & Business Media.
2.Bhowmick, A. K., & Stephens, H. (Eds.). (2000). Handbook of elastomers. CRC Press.

Image Courtesy:

1.’Coloured cast acrylic by Midton Acrylics’ By Craig Cameron – Own work, (CC BY-SA 3.0) via Commons Wikimedia
2.’Led e plexiglass 660, 2011, plexiglass, led e ottiche collimatrici’ By Verosky – Own work, (CC BY-SA 4.0) via Commons Wikimedia