News tagged with plastics

Study warns about bisphenol A substitutes

Two substitutes for bisphenol A, a plastic ingredient banned in some countries over health fears, are also a source of concern, French researchers warned Thursday.

Jan 15, 2015
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A close look at blinking after facial transplantation

Recovery of blinking function is a critical but easily overlooked outcome after facial transplantation, according to a report in the January issue of Plastic and Reconstructive Surgery, the official medical journal of the Americ ...

Dec 29, 2014
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Smartphone thumb skills alter our brains

When people spend time interacting with their smartphones via touchscreen, it actually changes the way their thumbs and brains work together, according to a report in the Cell Press journal Current Biology on Dec ...

Dec 23, 2014
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What's on your surgeon's playlist?

Music and medicine are deeply connected. But is operating to music a good idea? And, if so, what kind of music should theatre staff be listening to?

Dec 11, 2014
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Lifelong learning and the plastic brain

Our brains are plastic. They continually remould neural connections as we learn, experience and adapt. Now researchers are asking if new understanding of these processes can help us train our brains.

Nov 19, 2014
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Plastic

A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs. Monomers of plastic are either natural or synthetic organic compounds.

The word plastic is derived from the Greek πλαστικός (plastikos) meaning capable of being shaped or molded, from πλαστός (plastos) meaning molded. It refers to their malleability, or plasticity during manufacture, that allows them to be cast, pressed, or extruded into a variety of shapes—such as films, fibers, plates, tubes, bottles, boxes, and much more.

The common word plastic should not be confused with the technical adjective plastic, which is applied to any material which undergoes a permanent change of shape (plastic deformation) when strained beyond a certain point. Aluminum which is stamped or forged, for instance, exhibits plasticity in this sense, but is not plastic in the common sense; in contrast, in their finished forms, some plastics will break before deforming and therefore are not plastic in the technical sense.

There are two types of plastics: thermoplastics and thermosetting polymers. Thermoplastics are the plastics that do not undergo chemical change in their composition when heated and can be moulded again and again; examples are polyethylene, polypropylene, polystyrene, polyvinyl chloride and polytetrafluoroethylene (PTFE). Thermosets can melt and take shape once; after they have solidified, they stay solid.

The raw materials needed to make most plastics come from petroleum and natural gas.

This text uses material from Wikipedia licensed under CC BY-SA