【英语时差8,16】强力胶
时间:2016-01-25 06:58:22
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(单词翻译)
If you've ever had a spill when working with SuperGlue®, then you know that the warning on the side of the tube is the absolute truth: SuperGlue will indeed bond skin in a matter of seconds.
You may have wondered, as you were trying to
pry1 your fingers apart, exactly why SuperGlue is so good at bonding skin together. Why does it stick your fingers together so quickly, but not stick to the inside of the tube?
SuperGlue is the brand name of a type of glue made from a chemical called cyano-acrylate monomer. Cyano-acrylate monomers have some properties that are especially interesting to glue manufacturers.
Monomers are small
molecules2 that can join together to form long chemical chains. These chains, known as polymers, are pretty common in everyday life. For example, all plastics are made from polymer chains of simple molecules, as are all
synthetic3 fabrics4.
What makes the cyano-acrylate monomer so special is the speed with which it forms polymers, and the fact that as it joins together, it tends to lock everything else around it into place as well. This rapid
transformation5 from unsticky liquid monomer to sticky solid polymer requires the presence of a little bit of water to get things started---whether it is in the air or on your skin. Without a little moisture, SuperGlue can't bond anything.
This explains why the glue is so good at sticking fingers together. Our skin is naturally moist, and this moisture is just what those monomers are waiting for. As long as no moisture gets into the tube, however, it will stay an unsticky liquid for a long time.
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