Structure and properties of polymers Flashcards
The arrangement of molecules in a polymer affect…
the properties of a polymer
If polymer chains that make up a material are packed close together…
…the material will have a high density
If the polymer chains that make up a material are spread out…
…the material will have a low density
Name the 2 types of intermolecular forces between polymers
Strong intermolecular forces
Weak intermolecular forces
Polymers which have weak forces holding them together…
Can be stretched easily
Have a low melting point
Polymers which have stronger intermolecular forces holding them together…
Cannot be stretched very easily
Have high melting points
Sometimes there are chemical bonds holding polymers together as well as intermolecular forces. We call these chemical bonds…
Crosslinks
The stronger the intermolecular forces between polymer chains…
the more energy is needed to break them apart
the higher the melting point
How can polymers be modified?
We can increase or decrease their chain length.
Which type of polymer is easy to shape?
Short chained polymers
Which type of polymers have lower melting points?
Short chained polymers
Which type of polymers are stiffer?
Long chained polymers
Which type of polymers have a high melting point?
Long chained polymers.
How can we make a polymer stiffer?
Add cross linking agents
How do cross linking agents affect a polymer?
Make it stiffer
Stronger
Heat resistant
