Polymers

• What are the two types of polymerisation?

  Addition and condensation
• What is addition polymerisation?

  • Forms when unsaturated monomers react
  • Monomers contain C=C bonds
  • Chain forms by repeating the same basic unit
• What type of polymers are poly(alkenes)?

  Chemically inert and non-biodegradable
• Why are poly(alkenes) non-biodegradable?

  Due to strong C-C and C-H bonds
• What is the repeating unit in a polymer derived from but-2-ene?

  Drawn from the monomer's structure
• What is condensation polymerisation?

  • Involves two different monomers
  • A small molecule is released (e.g., H2O, HCl)
  • Common types: polyesters and polyamides
• What is formed when carboxylic acid reacts with alcohol?

  Ester and water
• What is the product of acyl chloride and alcohol reaction?

  Ester and HCl
• What do dicarboxylic acid and diol produce?

  Poly(ester) and water
• What is produced from diacyl dichloride and diol?

  Poly(ester) and HCl
• What do dicarboxylic acid and diamine yield?

  Poly(amide) and water
• What is the significance of the -1 in the Terylene reaction?

  Indicates H and OH are still present
• What is Terylene used for?

  Clothing and tire cords
• What is required to make an ester from carboxylic acid?

  An acid catalyst
• Why is acyl chloride preferred over carboxylic acid in reactions?

  It goes to completion without a catalyst
• What are the characteristics of Nylon 6,6?

  • Common polyamide
  • 6 carbons in each monomer
  • Different lengths produce different polyamides
• What type of polymer is produced from hexanedioic acid and hexane-1,6-diamine?

  Polyamide (Nylon 6,6)
• How can polyamides and polyesters be formed from one monomer?

  • Monomer must contain both functional groups
  • Can react to form polymers
• What is the common method of polymer disposal in the UK?

  Landfill
• What is a consequence of European regulations on landfill use?

  Increased charges for councils
• Why are polyalkenes problematic for disposal?

  They are non-biodegradable
• What are the advantages and disadvantages of incineration?

  Advantages:

  • Energy produced for electricity
  • Volume of rubbish reduced

  
  

  Disadvantages:

  • Toxins can be released
  • Greenhouse gases emitted
• What are the pros and cons of recycling polymers?

  Pros:

  • Saves raw materials
  • Reduces crude oil dependency

  
  

  Cons:

  • Expensive collection and sorting
  • Limited to same type recycling
• How can thermoplastic polymers be recycled?

  They can be melted down and reshaped
• How do polyesters and polyamides react to hydrolysis?

  • They can be broken down by hydrolysis
  • Result in original monomers
  • Carboxylic acid or amine in salt form
• What types of intermolecular bonding exist in polyesters and polyamides?

  Polyesters:

  • Permanent dipole forces
  • Van der Waals forces

  
  

  Polyamides:

  • Hydrogen bonding
  • Van der Waals forces
• Why do polyamides have higher melting points than polyesters?

  Due to hydrogen bonding in polyamides
• What explains the reactivity of condensation polymers?

  Presence of polar bonds attracting nucleophiles
• What is the significance of the polymer with both amide and ester links?

  • Contains both functional groups
  • Can undergo various reactions
• What is the by-product of hydrolysis of polyesters and polyamides?

  Original monomers
• What happens to the carboxylic acid or amine group during hydrolysis?

  It will be in salt form