Polymers

• A polymer is a long chain molecule formed from thousands of small molecules called monomers.

  There are two types of polymer, addition and condensation.
• Suggest why a polymer is biodegradable

  • It can be hydrolysed
  • can be reacted with by a acid , base , nucleophile
• Describe an experiment in which you would compare the biodegradability of those two objects

  • Heat , reflux with aqueous sodium hydroxide NaOH
  • PolyAlkene is inert , no reaction
  • polyamide is hydrolysed to for, acid salt and alcohol
• Describe +/- of a different method of disposal of such objects compared with landfill

  • combustion
  • heat energy produced
  • toxic gases produced
• 3 wyas we dispose of polymers in the UK

  Landfill

  Recycling

  Burning (fuel)
• addition polymerisation is the ....

  Formation of long chian NON POLAR molecules from lots of small molecules that when formed have NO OTHER PRODUCTS. Commonly from alkenes.
• adv and disadv for burying in landfill

  + quick and easy

  - expensive

  - releases CH4 gas

  - releases toxins that wash away into water supply
• adv and disadv for recycling

  + reduces landfill

  + saves raw finite materials

  + cost of recycling lower than using new materials

  + less co2 than burning

  
  

  - technically complex to sperate the plastics

  - collecting sorting is MORE expensive than landfill

  - can't often remake the plastic you started with

  - can easily get contaminated plastics
• adv and disadv of burning plastics

  + makes electricity

  - toxic products like HCL from PVC

  - CO2 from burning stuff
• compare PVC and uPVC giving uses for both

  PVC when placticised is more soft, it has placticers added in the polymerisation process and allows the layers to slide over each other giving properties suitable for kids toys vs uPVC being window frames and gutters.
• condensation polymers are _______

  biodegradeable
• compare Thermosetting and thermosoftening plastics.

  Thermosoftening plastic will melt when you heat it you can reshape it (recycling). Thermosetting wont will stay ridgid.
• Condensation polymers can be broken down with water. Why.

  Hydrolysis can happen beacuse it's a reversible reaction.

  It's slow tho!
• Define polymer


  long chain molecules made from lots of small molecules joined together
• draw hydrogen bonding between generic Poly(amide) layers.


  hydrogen bonds betwen polyamide layer see image

  
• amide linkage

  C=ONH
• explain why thermosetting polymers have a higher melting point than thermosoftening polymers and cannot be reshaped.

  Setting = Covalent bonds between layers

  Softening = No bonds between layers only IM forces

  Setting = would decompose before you got to the temp to reshape them.
• How can we speed up the hydrolysis of poly(amides)?

  acidic conditions
• How can we speed up the hydrolysis of poly(esters)?

  add NaOH ( basic conditions)
• polyalkenes are chemically inert, what is an advantage of this


  They won't react with food or drinks that are often contained.
• Polyalkenes are ______

  chemically inert and non-biodegradable.
• What are the three types of condensation polymers? How do we make them?


  Poly(esters) - Diol and Dicarboxylic acid

  Poly(amides) - Dicarboxylic acid and Diamine

  Poly(peptides) - Dicarboxylic acid and Diamine (OR 2 AMINO ACIDS OFTEN WHY WE CALL IT PEPTIDE)
• What do placticisers do?

  placticisers sit between the polymer chain layers allowing them to slide past each other as they intefere with the typical IM forces present. Makes PVC more flexible than uPVC
• What does the U stand for in uPVC

  Unplacticised.
• What should be done to lessen the impact of addition polymers on the environment?

  Recycle reuse and incinerate so less land fill waste.
• What's a monomer

  Smaller molecules that joins together to make polymers
• Why are addition polymers unreactive?

  Bonds are non polar so cannot be attacked by nucleophiles.
• Why are condensation polymers bio-degradable?

  They are polar

  So they are susceptible to :NU- Attack
• Why are poly(alkenes) not biodegradable

  They are chemically inhert.

  NON polar bonds

  so no suceptability to attack from neucleophiles like water.
• Why is the fact that addition polymers are unreactive bad for the environment?

  The lack of polar bonds means not biodegradeable.
• Naming alcohols in polyesters


  Remember to have add e on the end

  • propane- 1,3 - diol
• Name two types of polymer

  • addition
  • condensation
• Terylene

  • Benzene - 1,4 - dioc acid
  • ethane - 1,2 - diol
  • elastic
  • can resit corrosion
  • strong
  • waterproof
  • insoluble
  • inert
  • uses : fabric used in clothing, tire cords
• Kevlar

  • Benzene - 1,4 - dioic acid
  • benzene - 1,4 - diamine
  • incredibly tough , strong
  • has many hydrogen bonds between polymer chains which require a lot of energy to break
  • uses : bulletproof jackets , body armour
• Nylon 6,6

  • hexanedioic acid
  • hexane - 1,6 - diamine
  • strong elastic
  • uses : fibres, guitar strings
• Why are polyesters and polyamides not broken down by pure water

  With pure water it is too slow to be useful
• Base preferred over acid hydrolysis

  • Not reversible
  • approximately 100% yield
• Base preferred over acid hydrolysis

  • Not reversible reaction
  • approximately 100% yield
  • salt need to be neutralised to get just carboxylic acid
• +/- of recycling

  • Reduced amount of plastic disposed in landfill site
  • expensive as plasticisers must be collected, sorted and processed