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.

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 April 23, 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 April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
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:
from the past week

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