week 6

• Polymers


  Large molecules made of many small units joined to each other through organic reactions
• Monomers


  The small units that make up polymers
• Polymerization


  The method of creating synthetic polymers by combining smaller molecules, called monomers, into a chain held together by covalent bonds
• Elements commonly found in polymer backbones

  • Carbon
  • Hydrogen
  • Oxygen
  • Nitrogen
  • Sulfur
  • Chlorine
  • Fluorine
  • Phosphorous
  • Silicon
• Polymers with carbon backbones


  • Polyethylene
  • Polypropylene
  • Polybutylene
  • Polystyrene
  • Polymethyl pentene
• Polymers with other elements in the backbone

  • Nylons (contain nitrogen)
  • Polyesters and polycarbonates (contain oxygen)
  • Polymers with silicon or phosphorous backbones
• Types of polymers based on backbone

  • Organic polymers (carbon backbone)
  • Inorganic polymers (backbone not carbon)
• Classifications of polymers based on behaviour when heated

  • Thermoplastic (melt when heated and can be reshaped)
  • Thermosetting (do not melt when heated and keep original shape)
• Linear polymers


  • Long, straight chains
  • Molecules can slide past each other easily when heated
  • Typically thermoplastic
• Branched-chain polymers


  • Have side chains that prevent molecules from sliding past each other easily
  • Still likely to be thermoplastic
• Cross-linked polymers


  • Have stronger covalent bonds between adjacent molecules
  • Molecules cannot slide past each other when heated
  • Typically thermosetting
• Thermosetting polymers


  Polymers that do not melt when heated and retain their original shape
• Thermoplastic polymers

  Polymers that melt when heated and can be reshaped many times
• Types of polymer structures

  • Linear
  • Branched
  • Cross-linked
  • Networked
• Addition polymerization


  Small monomer units join to form a giant polymer, with the chain length increasing in each step
• Condensation polymerization


  Small molecules like H2O, CO, NH3 are eliminated during polymerization
• Copolymerization

  Two different monomers join to form a polymer
• Polymers can be very resistant to chemicals
• Polymers can be both thermal and electrical insulators
• Polymers are generally very light in weight with significant degrees of strength
• Polymers can be processed in various ways
• Polymers are materials with a seemingly limitless range of characteristics and colors
• Polymers are usually made of petroleum, but not always
• Polymers can be used to make items that have no alternatives from other materials
• Polymers are large molecules made of many small units joined to each other through organic reactions
• Polymerization is the method of creating synthetic polymers by combining smaller molecules, called monomers, into a chain held together by covalent bonds
• Polymers


  Materials made of long chains of repeating molecular units (monomers) connected by covalent bonds
• Major industries using polymers

  • Ceramic industries
  • Stem cell biology and Regenerative Medicine
  • Packaging industries
  • Food processing industries
  • Automotive industries
  • Aerospace industries
  • Electrical and electronic industries
• Researchers are experimenting with many different types of polymers, aiming to further medicine development and enhance products we already use
• Polymers being developed and enhanced for the automotive industry


  • Carbon-fiber-reinforced polymer (CFRP) composites
• Carbon-fiber-reinforced polymer (CFRP) composites


  • Extremely strong and stiff because of its woven layers of nearly pure carbon fibers bonded together by a hardened plastic, such as epoxy resin
• Polymers being used to enhance holograms

  • Hologram on flexible polymer material called PDMA embedded with gold nanorods
• Hologram on flexible polymer material called PDMA


  Can hold several images instead of just one
• The new hologram device can hold several images instead of just one
• Artificial skin made of a silicone polymer


  • May be able to tighten a person's skin, reduce the appearance of wrinkles and diminish under-eye bags
  • May also be used to help those with skin conditions, such as eczema, or be used as sun block
• Artificial skin made of a silicone polymer may be the future of anti-aging efforts