Shape Memory Polymers, an Overview

There are many opportunities to incorporate polymers, but one of the most interesting of them is shape memory polymers. This unique type of polymer is highly unique and growing in use because of its unique ability.

What Do Shape Memory Polymers Do?

Shape memory polymers are a type of active polymer that has dual-shape capability. That sounds a bit strange, but they are actually quite useful. These polymers can change their shape from one shape to the next (generally just from a predefined shape to another predefined shape). For this to happen, they need to be exposed to some type of stimulus (which is also designed and incorporated in the product itself).

These shape memory polymers are beginning to be seen in a wider number of applications. And, they are being used more readily in everyday life – not just in typical manufacturing or industrial facilities. For example, one of the first applications to be readily used by general consumers were films. When heat was applied to them, the films shrunk to create an air-tight fit for the product within them. There are many other examples, such as self-deploying sales used in aerospace industry applications and heat-activated tubes for electronics. Smart fabrics are another, and perhaps even more advanced example, of this technology.

What’s more, these polymers are working to change and save lives. For example, some are smart medical devices and implants that can be placed into the body through minimally invasive surgery and then enlarged or changed once in place.

How Does This Shape Changing Ability Happen?

To explain a bit more about how they work, consider these details. The first shape of these polymers, called Shape A, for example, is determined by a process called programming. Shape B, on the other hand, occurs when by the desired stimulus of Shape A.

These types of polymers fit into the family of actively moving polymers. That means they can change from one shape to the next rather easily. The first shape, Shape A, is considered a temporary shape that is usually developed using mechanical changes called deformations. Then, they are “fixed” in the second version, or Shape B.

The stimulus that makes these shape memory polymers, also known as dual shape materials, work range widely. Most of them use heat or light as their activator. There are others that use infrared light as well. Some change when they are immersed in water or when there are alternating magnetic fields at play. Still, others use other methods even more specialized.

What’s important to know about the shape changing process is that it only relies on the molecular architecture. There is no need for chemical structure specifications in repeating units. That allows for these properties to be adjusted to fit any needs that may be necessary.

Understanding How the Process Works

To provide a bit more insight into how shape memory polymers work and change, consider a bit more insight into how the materials operate. Whether a polymer adhesive or a film, they all work along the same basic function.

The polymers do not make this change on their own. There is nothing in the makeup of the polymers that allows them to intrinsically change from Shape A to Shape B. Rather, this change occurs as a result of a combination of processing and polymer morphology.

Programming is a unique and interesting process. As noted, processing is the term used to describe the design of these shape memory polymers. During this process, makers work through a series of steps. The initial step is to conventionally process the polymer into the desired Shape B – or permanent, final desired shape. From there, makers will then work through programming steps to deform the shape. This deformed version is called Shape A. In other words, the manufacturers work backwards from the desired finished product to create the temporary Shape A option.

Then, when the right (and specifically designed for) stimulus is applied, the polymer is then able to form back into the end desired result, Shape B. It remains in this shape. It is possible to repeat this process numerous times and, in some cases, it is also possible to create different temporary shapes of the polymers. The process of programming like this does not take long and can be far more effortless and time-consuming than other methods especially those related to shape memory alloys.

What Do Shape Memory Polymers Bring to the Table?

Whether being used in biomedical applications or in consumer products, they provide a very effective and highly unique benefit. This is a very evolving field, along with other aspects of the actively moving polymers family. Because it is changing so quickly and applying to more and more industry applications, it is quite an exciting situation. They will continue to grow in being valuable across sectors especially with newer methods including light-induced stimulation and alternating magnetic fields for remote actuation. These are some of the most profound changes to the way polymers have been used in the past.

Perhaps most interesting is the way that these polymers are fitting into the active medical devices and implants industry. There, they are working to solve some of the most intense and complex problems in a very simple to apply solution. Multifunctional materials that can meet the needs of individuals is likely to be something highly desirable for years to come.

There is new demand for shape memory polymers across many industries, and with more complexities added to them. For those industries that are most suited for these polymers, it’s time to take a closer look at how they can work. It’s also readily possible to see comprehensive changes to operations because of these products in many applications.

At Polymer Chemistry, we are working with some of the most innovative and unique polymers to create highly effective and incredibly useful solutions. To learn more about the work we are doing or to find out how we can help you with your need for shape memory polymers, contact our team today.