Polymers. What Are Polymers? Large molecule that consists of lots of small repeating subunits...
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Transcript of Polymers. What Are Polymers? Large molecule that consists of lots of small repeating subunits...
Polymers
What Are Polymers?
•Large molecule that consists of lots of small repeating subunits•Subunits are called monomers•Polymers are formed when monomers are linked together is a process called polymerization
Addition Polymers
•Polymers are linked through addition reactions
•Three stages in synthesis• Initiation• Propagation• Termination
A A + A A + A A A A A A A A
A B A B A B A B A B A B + +
Polyethylene
•Polymer made from ethene monomers
Polyethylene
•Polymer made from ethene monomers
•Short form notation:
C C
H
H H
H
C C
H
H H
H
C C
H
H H
H
+ + C C C C C C
H
H
H
H
H
H
H
H
H
HH
H
nC CH
H
H
H
Polyethylene
Polypropene
•Made from propene monomers
Polypropene
•Made from propene monomers•Used in rope and carpets
•Short form notation:
C C C C C C
CH3
H
H
H
CH3
H
H
H
CH3
HH
H
C C
H
H CH3
H
C C
H
H CH3
H
C C
H
H CH3
H
++
C C
H
H CH3
H
n
Polyvinyl Chloride (PVC)
•Made with chloroethene (vinyl chloride) monomers
Polyvinyl Chloride (PVC)
•Made with chloroethene (vinyl chloride) monomers•Used in electrical wire insulation, plastic piping, coating on fabrics
•Short form notation:
C C C C C C
Cl
H
H
H
Cl
H
H
H
Cl
HH
H
C C
H
H Cl
H
C C
H
H Cl
H
C C
H
H Cl
H
++
C C
H
H Cl
H
n
Polystyrene
CH C
n
CH C
n
Polystyrene
•Made from (styrene) phenylethene •Very commonly used
Substituted Groups
•Change the properties of polymer
•Teflon monomer: tetrafluroethane
•Plexiglass monomer: methyl propenoate
Crosslinking•Occurs when links can be formed in 2 directions
• Diene monomers can form bridges between chains
•Diene doesn’t have to be main monomer•Increases polymers’ strength
Plastic Properties
•Substituted ethene (vinyl) monomers considered “plastics”•Saturated alkanes
• Very stable• Unreactive
•Flexible and mouldable solids or liquids
• Weak van der Waals forces•Softened by heating
• Disrupts forces
Condensation Polymers
•Monomer units are joined by condensation reactions•Monomer units must have functional groups at each end
Polyesters•Formed between dicarboxylic acid and diol
Polyesters•Formed between dicarboxylic acid and diol
OHCR
O
COH
O
+ O R O HH
CR
O
C
O
O R O
OH2+
nOH2
Polyamides
•Formed between dicarboxylic acid and diamine
Polyamides
•Formed between dicarboxylic acid and diamine
OHCR
O
COH
O
+ N R N HH
H
H
CR
O
C
O
N R N H
H
OH2+
n
OH2