Add to favorite
Subscribe to our Newsletters Subscribe to our Newsletters Get Daily Updates RSS

Another Composite Material Better than Polyethylene
November 28, 2008 16:56


Russian chemical physicists developed a new composite material, which looks like polyethylene, but has improved properties. New composite is much more rigid and better resists high temperatures. These remarkable properties said material owes to the layer mineral with exotic name montmorillonite, which origins from Montmorillon settlement in France. The composite has only traces of montmorillonite, however, authors worked very hard to insert these traces into polymer matrix. Scientists developed an elegant synthesis technique, which solves previously unmanageable problem keeping mineral structure intact, while introducing it into a polymer with absolutely different chemical nature.

Theres no need to dedicate much time to explaining why polyethylene properties should be improved. Polyethylene is very sensitive to heating it deforms, quickly get fire and burns almost entirely. Polar polymers, such as polyesters and polyvinyl chloride, are a grateful material they accept up to 90% of mineral additives, resulting in rigid non-combustible materials. Well, this does not work with polyethylene his chemical nature prevents its matrix from binding with mineral particles. Id rather say prevented, because Russian scientists found a back-door entrance, which is described below.

Authors of the technique used unusual filling agent a mineral, which consists of numerous layers like a large book however, these layers are not bonded. We should be thoroughly honest authors used non-natural mineral, but slightly modified. This modified montmorillonite had expanded space between the layers, and layer surface contained organic (more hydrophobic) cations instead of part of original sodium. The question is what is the way of introducing this filling agent into the polymer matrix to keep minerals layer structure and to make the mineral uniformly distributed? It is not just heating and mixing. Authors found out that the mineral should first be saturated with a catalytic agent (this can be done by adsorption into interlayer space), and only after that ethylene should be polymerized.

Structure of montmorillonite
Since the catalytic agent is located both inside and outside mineral layers, polyethylene forms inside and outside mineral layers as well thus multilayer filling becomes tightly bonded with polyethylene matrix. The result is new composite material, with evenly distributed nanolayers of montmorillonite (which as any clay doesnt burn and doesnt stretch under heating) in the total volume of polyethylene.

Scientists thoroughly studied the structure of the new material and its properties. They used many techniques and, what is notable, were the first, who used the technique of very cold (it means very slow) neutron scattering. Researchers found out that they can synthesize the material with predetermined structure and properties by varying synthesis parameters and mineral modifications. Introduction of as little as 1-3 volume percent of montmorillonite significantly reduces (compared to polyethylene) flammability and gas permeability of the new composite, as well as increases its thermal stability. If you imagine that your composite gets on fire, it would burn slowly, turning into a small laminated coal nothing to do with a flame. Russian scientists claim they understand the mechanism of this phenomenon, which is very important for science and technology. And what makes sense for users (ordinary people), is non-flammable and thermostable composite polyethylene this means safe and universal.

Source: Russian Science News

Kizilova Anna


Next Previous

You might also find interesting:

How Lightnings Form Ozone Holes Disappear Without Human Interference Biochemists Predict Properties Of Fusion Proteins Fast-growing Poplar Breeding Project Ebola Virus Vaccine Passed First Stage of Clinical Trials in Novosibirsk

Comment on our site

RSS   twitter   facebook   submit

Bookmark and Share

search on the map
Olympics 2012  Russian Cinema  Victor Pelevin  Mercedes-Benz Fashion Week Russia  Russian regions  Severstal  Artists  Joseph Stalin  Books  Space Stations  Museums in Samara  Moscow  Concerts in St.-Petersburg  Aeroexpress  Pussy Riot case  Lake Ilmen  Irkutsk Region  pedestrian bridges  Kazan  Kaluga Region  Exhibitions in Moscow  travel to Russia  Medical Center FEFU  Festivals in Moscow  Russian artists  Design  Innovations  Puppets  Ramzan Kadyrov  Natalya Vodianova  aircraft  culture  St. Petersburg  Space Training  Golden Ring  North Pole cruises  Anatoly Karpov  Russian Composers  Russian tourism  Votkinsk  Film Archives  corruption in Russia  Russian winter  Ferapont Monastery  IT  FIFA Russia 2018  Tver  Russian parliament  VKontakte  Russian business 

Travel Blogs
Top Traveling Sites