Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists Reinvent the Science and Industry of Making Plastics

16.10.2006
Chemists at the University of Pennsylvania have created a new process for free radical polymerization, the chemical reaction responsible for creating an enormous array of everyday plastic products, from Styrofoam cups to PVC tubing to car parts.

Unlike the traditional method for living polymerization, which has been around for more than 50 years, this method takes place at room temperature, uses less metal catalyst to drive the reaction and requires a very short reaction time.

We have basically re-written the equation of how the polymerization process can work, which can have a direct impact on the cost of the reaction and the types of materials that we can create. said Virgil Percec, a professor in Penns Department of Chemistry. Polymerization is a billion-dollar-a-year industry, and the applications for the technology are enormous, ranging from medicine to coatings, from moldable forms of rubber to electronics and even complex organic synthesis, all via these radical reactions.

This new technique, called Single Electron Transfer-Living Radical Polymerization, also offers chemists greater control over the molecular architecture of the polymers they create and allows them to use materials that did not work with the traditional process. The mechanism of the synthesis reaction works so well that there is very little worry about undesirable side reactions, and the resulting polymers do not need to be purified to remove the catalyst. Their findings are presented in the Journal of the American Chemical Society, available online now.

The SET-LRP mechanism can allow for a greater control over the three-dimensional structure of the polymers being created, Percec said. The overall process is not only more efficient, it also provides industrial chemists a new creative tool for building consumer and industrial.

Polymerization links individual molecules, referred to as monomers, together to form synthetic products on a larger-scale. In the chemical reaction to create polymers, chemists use catalysts to decrease the amount of energy it takes to create a shared bond between individual atoms of each monomer. The traditional method, referred to as atom-transfer radical polymerization or metal catalyzed living radical polymerization, demands high temperatures and a great amount of the metal catalyst, in part, because the process depends on the energy it takes to transfer inner-sphere electrons - which are deep within the cloud of electrons surrounding an atom - in the act of bonding monomers together.

The new method created by Percec and his colleagues involves the transfer of outer-sphere electrons, which requires much lower activation energy and, therefore, a different catalytic cycle than atom-transfer radical addition. Both the traditional and SET-LRP processes use copper-based catalysts to drive the reaction, but the SET-LRP reaction uses a common, elemental form of copper - in the form of powder or wire - in the presence of environmentally friendly solvents, such as water, to move the reaction along. This prevents the build up of excess amounts of copper by-products and reduces the need to continually add more catalyst to keep the reaction going.

While this might seem like a refinement of the traditional process - the resulting polymers, in fact, are structurally the same - this method involves an entirely different approach to the chemical reaction, Percec said.

Funding for the research was provided by the National Science Foundation.

Greg Lester | EurekAlert!
Further information:
http://www.upenn.edu

Further reports about: Monomer Percec Polymers catalyst polymerization reaction

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>