L1 /
10
CH1012
POLYMER STRUCTURE
• Polymers are amorphous
solids. There
is some short range order which is
referred to as the degree of crystallinity.
is some short range order which is
referred to as the degree of crystallinity.
• Intermolecular
forces hold the chains
together to form the crystalline regions,
this can be enhanced by mechanical
stretching of the molten polymer.
together to form the crystalline regions,
this can be enhanced by mechanical
stretching of the molten polymer.
• Low Density
PolyEthylene MW 104 has
many side chains which inhibit crystallinity
eg. Gladwrap®
many side chains which inhibit crystallinity
eg. Gladwrap®
• High Density PolyEthylene
MW 106 has few
branches and higher crystallinity (85%) making it harder and denser. eg. bottles
branches and higher crystallinity (85%) making it harder and denser. eg. bottles
