Understanding Polymers in Chemistry

Sep 3, 2024

Stage 2 Chemistry: Subtopic 4.4 - Materials

Overview

  • Subtopic 4.4 covers materials, particularly focusing on polymers.
  • The topic is divided into three parts, with the current focus on polymers, specifically addition and condensation polymers.

Polymers

  • Definition: Long chain molecules consisting of repeating units.
  • Types:
    • Addition Polymers
    • Condensation Polymers

Monomers vs. Repeating Units

  • Monomers: Building blocks of polymers.
  • Repeating Units: Not the same as monomers but are the structural motif that repeats within a polymer.

Addition Polymers

  • Formation: From addition reactions where monomers contain carbon-carbon double bonds.
  • Characteristics:
    • No atoms are lost in the polymerization process.
    • Carbon-carbon double bonds are converted into single bonds.
  • Examples:
    • Polyethene/Polyethylene: Formed from ethene.
      • Used in plastic bags.
    • Polyvinyl Chloride (PVC): Formed from vinyl chloride.
      • Commonly used in pipes and plumbing.

Condensation Polymers

  • Formation: By condensation reactions, often releasing a small molecule like water.
  • Types:
    • Polyesters
      • Formed from ester functional groups.
      • Can be made from one monomer (hydroxycarboxylic acid) or two monomers (diol and dicarboxylic acid).
    • Polyamides
      • Formed from amide functional groups.
      • Can also be made from one monomer (amino carboxylic acid) or two monomers (diamine and dicarboxylic acid).

Examples of Condensation Polymers

  • Polyethylene Terephthalate (PET)
    • Made from benzene 1,4-dioic acid and ethane 1,2-diol.
    • Commonly used in manufacturing plastic bottles.
  • Nylon 6-6
    • Made from 1,6-hexane diamine and hexane dioic acid.
    • Used in products like toothbrush bristles, parachutes, and stockings.

Key Points

  • Understand the structural differences and formation processes between addition and condensation polymers.
  • Recognize the applications and significance of different types of polymers in everyday products.

Conclusion

  • This session covered part one of polymers under subtopic 4.4. Further discussions and examples will be explored in subsequent videos.