polymers


A lunarlike polymeric surface in microscale

What are polymers? – Polymers are everywhere. Just look around. Your plastic water bottle. The silicone rubber tips on your phone’s earbuds. The nylon and polyester in your jacket or sneakers. The rubber in the tires on the family car. Now take a look in the mirror. Many proteins in your body are polymers, too. Consider keratin (KAIR-uh-tin), the stuff your hair and nails are made from. Even the DNA in your cells is a polymer. Polymers, whether artificial (such as the plastic shown) or natural, are made of repeating chains of smaller chemical units. Here, carbon atoms are shown as black, oxygen as red and hydrogen as white.

Kevlar chemical structure H-bonds

Polymers – synthetic plastics such as polystyrene (of styrofoam) and natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are large molecular mass relative to small molecule compounds produces unique properties such as toughness, viscoelasticity,

Natural

  • DNA and proteins

Synthetic

  • hydrogel

types of polymer bonds

  • Linear
  • Branched
  • Crosslinked
  • Network (3D)

tissue engineering

  • Self Healing Polymers – new polymer can repair itself from ingredients in the air – only carbon dioxide and water vapor; two ingredients which occur just about everywhere. From Urban’s research website, “This process requires atmospheric amounts of CO2 and H2O, thus resembling plant behavior of carbon fixation during the photosynthesis cycle.”
  • Cheap polymers twist into superhuman muscles – sewing thread and fishing line. Twisting nylon and polyethylene into coils, they made artificial muscles that can lift loads over 100 times heavier than human muscle of the same length and weight. They could replace motors in many uses, particularly robotics, and enable new technologies, such as smart clothing, says Ray Baughman from the University of Texas, Dallas. He’s also excited that the threads used cost just $5/kg (£3/kg). ‘They could be easily deployed in the developing world, children could make and use them,

Engineering ideas

  • tough, viscoelastic, load, polyethylene, nylon