PaintSquare.com


The First Word in Protective & Marine Coatings

A Product of Technology Publishing / PaintSquare
JPCL | PaintSquare News | Durability + Design | Paint BidTracker

Paint and Coatings Industry News

Main News Page


UV Heals New Polymer Repeatedly

Friday, January 21, 2011

Comment | More

U.S. and Japanese scientists have developed a polymer that can heal itself over and over again when irradiated with UV light.

This is the first material in which capped covalent bonds reattach repeatedly, even allowing fully separated pieces to be fused back together, the team reports in Angewandte Chemie, the peer-reviewed journal of the German Chemical Society.

In "Repeatable Photoinduced Self-Healing of Covalently Cross-Linked Polymers through Reshuffling of Trithiocarbonate Units", the research team explains how the new polymeric material repairs itself repeatedly.

shredded polymer samples

The technology could have significant implications for protective coatings and other functional materials subject to damage and weathering.

Restructuring Under UV Light

Previous materials have been able to repair themselves once. Typically, these contain tiny capsules that tear open to release a chemical agent when the material is damaged, explains journal publisher Wiley. Other materials “can repair themselves repeatedly but lack the covalent bonds that increase materials strength and stability.”

The new polymer, however, is cross-linked through trithiocarbonate units, Wiley explains. These carbon atoms are bonded to three sulfur atoms, two of which use their second bonding position to attach to another carbon atom.

“These groups have a special property: They can restructure under UV light,” according to Wiley. “The light breaks one carbon–sulfur bond in the trithiocarbonate groups. This produces two radicals—molecules with a free, unpaired electron.

“The radicals are very reactive and attack other trithiocarbonate groups to form new carbon–sulfur bonds while breaking others to form more free radicals. The chain reaction stops when two radicals react with each other.”

Healing Cut Fragments

The material was developed by Krzysztof Matyjaszewski and colleagues at Carnegie Mellon University in Pittsburgh, PA, and Kyushu University in Japan.

“The researchers were able to heal cut polymer fragments with irradiation—either immersed in liquid or in bulk,” the journal reported. “They only had to firmly press the cut edges together and irradiate them” to cause the edges to grow back together.

Even shredded polymer samples could simply be pressed together and irradiated to be fused into a continuous piece, the publisher said.

“The resulting object was in the shape of the cylindrical tube in which the procedure was carried out. This self-healing process can be carried out repeatedly on the same sample. The material is thus also interesting as a new recyclable product.”

   

Tagged categories: Polymers; Research

Comment Join the Conversation:

Sign in to our community to add your comments.

Harsco
Find BLACK BEAUTY® Abrasives

Use our online tool to search by address, city or zip code to find where you can buy BLACK BEAUTY® abrasives. Or call us toll free: 1-888-733-3646


Mohawk Garnet
Enska by Mohawk Garnet™

A safe, efficient and economical abrasive alternative to slag and sand products. More information
at 1.866.642.7638 or info@mohawkgarnet.com Email for follow up – mheilimo@mohawkgarnet.com


Clemco Industries Corp.
Powerful Protection in a Small Package

Mounts inside blast helmet, alerts operator to dangerous breathing-air condition by audible, visual, and vibratory alarms. Easily calibrated, battery operated.


DRYCO
Environmental Controls
Equipment & Service

Temporary climate control equipment. Dehumidifiers,
Heaters, A/C, Power, More…
Toll Free: 866-379-2600


Industrial Vacuum Equipment Corp.
Hurricane Vacuums
& Dust Collectors

Vacuum and dust collector hose, filters and related accessories.
IndustrialVacuum.com


DeFelsko Corporation
PosiTector Dew Point Meter

Measures and records
environmental conditions
during surface prep and
painting. 4 Models
Available – Standard
or Advanced features,
Built-in or Separate probe.


ABKaelin, LLC
Quality is our bottom line

Services include:
• Environmental, Health &
  Safety
• Contractor QP Certification
• Quality Assurance Programs
  and Auditing
• SSPC C3/C5 and other
  Training
• Coatings
• Design/Construction
See our website at abkaelin.com or contact us today abkaelin@comcast.com

 
 
 
Technology Publishing

The Technology Publishing Network

The Journal of Protective Coatings & Linings (JPCL) PaintSquare
Durability + Design Paint BidTracker JPCL Europe

 
EXPLORE:      JPCL   |   PaintSquare News   |   Interact   |   Buying Guides   |   Webinars   |   Resources   |   Classifieds
REGISTER AND SUBSCRIBE:      Free PaintSquare Registration   |   Subscribe to JPCL   |   Subscribe to PaintSquare News
MORE:      About PaintSquare.com   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us
 

© Copyright 2000-2014, Technology Publishing / PaintSquare, All rights reserved
2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951; Tel 1-412-431-8300; Fax 1-412-431-5428; E-mail webmaster@paintsquare.com