Featured Research

from universities, journals, and other organizations

Off-the-shelf materials lead to self-healing polymers

Date:
February 4, 2014
Source:
University of Illinois at Urbana-Champaign
Summary:
Look out, super glue and paint thinner. Thanks to new dynamic materials, removable paint and self-healing plastics soon could be household products. A slight tweak in chemistry to elastic materials made of polyurea, one of the most widely used classes of polymers in consumer goods, yields materials that bond back together on a molecular level without the need for other chemicals or adhesives.

A close-up of an elastic polymer that was cut in two and healed overnight.
Credit: Anne Lukeman

Look out, super glue and paint thinner. Thanks to new dynamic materials developed at the University of Illinois, removable paint and self-healing plastics soon could be household products.

Related Articles


U. of I. materials science and engineering professor Jianjun Cheng, graduate student Hanze Ying and postdoctoral researcher Yanfeng Zhang published their work in the journal Nature Communications.

"The key advantage of using this material is that it's catalyst-free and low-temperature, and can be healed multiple times," Cheng said. "These are very nice materials for internal cracks. This can heal the crack before it causes major problems by propagating."

Other self-healing material systems have focused on solid, strong materials. However, the new study uses softer elastic materials made of polyurea, one of the most widely used classes of polymers in consumer goods such as paints, coatings, elastics and plastics.

After the polymer is cut or torn, the researchers press the two pieces back together and let the sample sit for about a day to heal -- no extra chemicals or catalysts required. The materials can heal at room temperature, but the process can be sped up by curing at slightly higher temperatures (37 degrees Celsius, or about body temperature). The polymer bonds back together on the molecular level nearly as strongly as before it was cut. In fact, tests found that some healed samples, stretched to their limits, tore in a new place rather than the healed spot, evidence that the samples had healed completely.

The researchers use commercially available ingredients to create their polymer. By slightly tweaking the structure of the molecules that join up to make the polymer, they can make the bonds between the molecules longer so that they can more easily pull apart and stick back together -- the key for healing. This molecular-level re-bonding is called dynamic chemistry.

Dynamic chemistry has been explored in some other polymers, but those materials tend to be for specialized applications or laboratory settings, rather than the conventional polymers used commercially. By focusing on consumer materials and using readily available ingredients, the researchers hope that manufacturers could easily integrate dynamic materials.

"We just buy commercial materials and mix them together, no fancy controls or special apparatus," said Cheng. "It's a very simple, low-cost, inexpensive process. Anybody can do this on any scale."

Now that they've established the chemistry required, the researchers are exploring how dynamic polyurea could bolster different applications. For example, they could fine-tune the mixture so that a polyurethane coating or paint could be removable.

"In some areas, when it's not necessary for the coating to be permanent and you want it to be removable, this chemistry may be applied to existing coating materials to make it reversible," Cheng said. "In general, polyurea and polyurethane are widely used. This chemistry could modify existing materials to make them more dynamic, healable."

The National Science Foundation and the National Institutes of Health supported this research. Cheng also is affiliated with the departments of chemistry and of bioengineering, the Beckman Institute for Advanced Science and Technology, the Institute for Genomic Biology, the Frederick Seitz Materials Research Laboratory and the Micro and Nano Technology Laboratory at the U. of I.

See a video demonstrating the preparation and self-healing properties: http://www.youtube.com/watch?v=1i3yoK0C9Ag


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hanze Ying, Yanfeng Zhang, Jianjun Cheng. Dynamic urea bond for the design of reversible and self-healing polymers. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4218

Cite This Page:

University of Illinois at Urbana-Champaign. "Off-the-shelf materials lead to self-healing polymers." ScienceDaily. ScienceDaily, 4 February 2014. <www.sciencedaily.com/releases/2014/02/140204154610.htm>.
University of Illinois at Urbana-Champaign. (2014, February 4). Off-the-shelf materials lead to self-healing polymers. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2014/02/140204154610.htm
University of Illinois at Urbana-Champaign. "Off-the-shelf materials lead to self-healing polymers." ScienceDaily. www.sciencedaily.com/releases/2014/02/140204154610.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Building Google Into Cars

Building Google Into Cars

Reuters - Business Video Online (Dec. 19, 2014) Google's next Android version could become the standard that'll power your vehicle's entertainment and navigation features, Reuters has learned. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
AP Review: Nikon D750 and GoPro Hero 4

AP Review: Nikon D750 and GoPro Hero 4

AP (Dec. 19, 2014) What to buy an experienced photographer or video shooter? There is some strong gear on the market from Nikon and GoPro. The AP's Ron Harris takes a closer look. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Obama: Better Ways to Create Jobs Than Keystone Pipeline

Obama: Better Ways to Create Jobs Than Keystone Pipeline

AFP (Dec. 19, 2014) US President Barack Obama says that construction of the Keystone pipeline would have 'very little impact' on US gas prices and believes there are 'more direct ways' to create construction jobs. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins