Polymers Flashcards
What is a Condensation reaction
When a small molecule eliminated ( Usually H2O ) to form a larger molecule
What is a condensation polymer
formation of all long chain molecule from reacting lots of small molecules (monomers) together
within each reaction a small molecule is released
What is an addition polymer
Formation of long chain molecules from lots of small molecules (Monomers) with no other products released
What properties should monomers of a condensation polymer have?
Has two functional groups
Give 3 examples of polymers
Polyesters
Polyamides
Polypeptides
What is the linkage in a polyester
What are the two monomers which form a polyester
Diol & Dicarboxilic acid
or a molecule with both alcohol and carboxylic acid functional groups
What is Terylene?
What is it used in?
Draw its monomers
A polyester
Used in plastic drink bottles, clothes and sheeting
Has the acronym PET
Draw the repeating unit of Terylene
What is the Linkage in a polyamide
Peptide
What are the two monomers to form a polyamide
DiAmine and DiCarboxilic Acid
Name 2 Examples of Polyamides
Nylon & Kevlar
Which Monomers make up Nylon-6,6
What is Nylon?
What is it used in?
Hexanedioic Acid & 1,6-diaminohexane
Polyamide
Used in ropes carpets, clothing and parachute fabrics
Draw the Polymer Nylon-6,6
What are Kevlar Monomers?
What is Kevlar?
What are its used?
Benzene-1,4-dicarboxilic acid 1,4-diaminobenzene
Polyamide
Used in bulletproof vests, car tyres, racing helmets and some sports equipment
Lightweight and Strong
Draw the repeating unit of kevlar
Why is Kevlar So Strong
Rigid chains and Close Packings of flat aromatic rings
What are polypeptides, What is the Linkage
Peptide
When many amino acids join together to form a long chain of molecules with peptide links and covalent bonds
Consists of only amino acids joining
Draw a Dipeptide
Why are poly(alkenes) Not biodegradable
Non polar C-H and C-C bonds with similar electronegativities
No permanent dipole that attracts nucleophile, or be broke down by enzymes
No portion of high electron-density that can react with electrophile
This means it cannot be hydrolysed & broken down
Why is it bad to burn polyalkenes
Releases Greenhouse gasses, CO2 .
Carbon Soot, C
and Carbon monoxide ,CO with other toxic chemicals from monomers
Where do most polyalkenes end up?
In Landfill as burning is unhealthy for the environment
Why can Condensation Polymers be broken Down
How are Condensation Polymers broken down?
They have Polar Bonds
Hydrolysis (opposite of condensation)
Why doesn’t industry execute hydrolysis under standard conditions
Very Slow Rate in Standard Conditions
What is the Difference Between Addition and Condensation Polymerisation?
Both form large molecules from monomers containing two function groups
Addition polymers breaks a Double bond to form only 1 product
Condensation polymers eliminate a small molecule to connect the monomers together
Explain the Hydrogen Bonding Between Polyamides (2)
Both C=O and N-H are Polar bonds Due to large differences in electronegitivity between the atoms.
The induced dipole is so strong that Delta Positive C and H form hydrogen bonds with the lone pair of electrons on another molecule ( Oxygen)
How Do Polyesters not show Hydrogen Bonding
All O-H bonds are removed leaving no delta positive atoms for lone pairs to hydrogen bond too.
What are the advantages & Disadvantages to using addition polymer plastics such as polyalkenes
Unreactive
Can be used in containing consumable products
No Polar bonds so not biodegradable
Goes to landfill and doesn’t degrade well.
What are the disadvantages to landfill?
Non Sustainable - Large amounts of land needed
Non Environmentally Friendly - Waste decomposes and produces methane and water can be contaminated by the leaching of plastics
What are the Advantages and disadvantages to Incineration of waste
Can be used to create power
Burning plastics can release toxic fumes
needs Flue gas scrubbers to neutralise acidic toxic gases
Name 4 Advantages of Recycling Plastic
Cheaper then Making Plastics from Scratch
Less Carbon dioxide produced then incineration
Reduces reliance on landfill
Preserves non-rentable raw materials
Name 4 Disadvantages of Recycling Plastics
Can be contaminated with other materials when being recycled
Difficult to sort plastics due to a large variety
Difficult to remake original o plastic from recycled material
Expensive compared to incineration or landfill
Explain How the structure of these polymers give rise to their uses
HDPE has molecules that are more closely packed then LDPE, as LDPE has branched molecules
This means HDPE has larger VDW intermolecular forces between molecules
This makes HDPE more rigid then LDPE.
Molecules in LDPE have more space to move so it is more flexible.
