Polymers and their Properties
C2: Chapter 2
Learning Objectives• To be able to list and state uses of commonly used
polymers
• To be able to recall and describe the conditions required for the production of LDPE, HDPE, thermosetting and thermosoftening polymers
• To be able to explain how the properties of polymers arise
• CHALLENGE : To be able to apply your understanding of intermolecular forces to thermosetting and thermosoftening polymers
Starter Activity What do you remember from year 10?
Polymers
What is a single unit
of a polymer called?
Where do polymers
come from?
Can you define a
polymer?
Can you name some examples?
5 minutes
Polymers• Polymers are made of
monomer units
• Monomers undergo a polymerisation reaction and make polymers
• A polymer is a substance made from large molecules made up of many repeating units (monomers).
LO1:To be able to list and state uses of commonly used polymers
Polymer Party VideoDraw and fill in this simple chart as we watch a
short video on polymers
LO1:To be able to list and state uses of commonly used polymers
Name of Polymer Name of Monomer Uses of Polymer
Natural vs. Synthetic Polymer Quiz
NATURAL SYNTHETIC
LO1:To be able to list and state uses of commonly used polymers
WOOLCarpert and Clothing
LATEXGloves, Condoms, Balloons
POLYESTERClothing, Seat Belts, Blankets
NYLONClothing, Fishing Lines
SILKClothing, upholstery and parachutes
TEFLONCable insulator, non stick pans
Polymer Research Activity• Use the exercise books to complete the table
15 minutes15 minutes
EXTENSIONPolymer Exam Question
LO2:To be able to recall and describe the conditions required for the production of LDPE, HDPE, thermosetting and thermosoftening polymers
Peer MarkLDPE HDPE Thermosoftening Thermosetting
Structure Low density branched chains which prevent tight packing
High density straight chains which allow for
tight packing
Long straight chains that are all tangled
Rigid structure with fixed chains
Bonding and Forces
Weak intermolecular
forces
Strong intermolecular
forces
Weak intermolecular forces that are
easily broken with heat
Strong covalent bonds linking
chains together (cross links) don’t
break when heated
Formation High pressure(and trace oxygen)
Low pressure(and catalyst at
50oC)
N/A N/A
Properties Weak structure with low melting
points
Strong structure with high melting
point
Soften when heated and can be remoulded
Do not soften when heated, just burn.
LO2:To be able to recall and describe the conditions required for the production of LDPE, HDPE, thermosetting and thermosoftening polymers
Key Question
How do the properties of polymers arise?What do the properties depend on?
Discuss with the person next to you
HINT: LOOK AT YOUR TABLE, think about our lesson on alloys!
LO3:To be able to explain how the properties of polymers arise
2 minutes2 minutes
Polymer Properties
• The properties of a polymer depend on:– The monomers used to make it– The conditions under which the polymer is made– The strength of the forces between molecules
LO3:To be able to explain how the properties of polymers arise
Prediction Challenge
Based on your understanding of intermolecular forces and the structure of polymers, DRAW
what you think thermosoftening and thermosetting polymers look like
CHALLENGE : To be able to apply your understanding of intermolecular forces to thermosetting and thermosoftening polymers
2 minutes
Thermosoftening vs. Thermosetting
• Thermosoftening• Polymer chains are easy to
separate• Forces broken when heated • When polymer cools forces
pull the molecules back together
• Thermosetting• Chains fixed together by
strong covalent bonds• Bonds stop the chains
separating• When heated strongly the
polymer will burn/char.
CHALLENGE : To be able to apply your understanding of intermolecular forces to thermosetting and thermosoftening polymers
Plenary• The polymer chains in a thermosoftening
polymer form a web. The polymer softens at relatively low temperatures. Other polymers have strong bonds between their chains which form
. We call these polymers.
Covalent Thermosetting Tangled Cross Links
tangled
covalent
cross links
thermosetting
5 minutes
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