UCL News


Plastics' molecular structures explained

3 July 2006

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A multidisciplinary team conducting work into the development of new plastics is exhibiting some of its work at the Royal Society Summer Science Exhibition.  

'Puzzling Plastics' displays the work of the Microscale Polymer Processing (MuPP) team, funded by the Engineering and Physical Sciences Research Council (EPSRC). The team brings together chemists, mathematicians, physicists, computer scientists and engineers from academia and industry, including UCL mathematician Dr Helen Wilson.

The MuPP team is unravelling the complexities of molecular behaviour in liquid polymers and leading the way to the development of new and advanced materials, for everything from drinks packaging to high performance sports equipment and the new generation of polymer-based electronics. Visitors are taken through the complex processes involved in the production of plastics, and learn about how the development of new plastics is very difficult because the molecular structure of polymers makes their behaviour unpredictable.

The main part of the exhibit is an extruder, which moulds plastics at different speeds into a thin tape. Examining the tape reveals how molecular stresses depend on the speed of the extruder. Three other displays, aimed more at the children visiting the exhibition, contain silly putty, which has highly unusual physical properties, a light box and polaroid sunglasses, which reveal the stresses that are 'frozen' into plastics when they are made, and yoghurt pots, which go flat when heated up. Each is designed to illustrate the diverse properties caused by plastics' molecular structures.

Dr Wilson commented: "We'll be showing people just how important these complex molecules are, and how much of their effects you can see in everyday objects. It's very exciting working with such an interdisciplinary team - not a chance many mathematicians get. We have everyone from chemists making new molecules and engineers measuring what they do, to physicists designing equations to match the molecules and mathematicians solving them."

The Royal Society Summer Science Exhibition runs from 3-6 July 2006.

Image: Stress patterns caused by extruding a linear polymer through a slit. The colours show how stressed the polymers are. Computer simulation by Dr Mehmet Sahin, UCL Mathematics