POLYMERS Flashcards
1
Q
Name four differences between polymers and small molecules
A
- Aggregated states - polymers cant be gaseous
- Dissolution - polymers swell first
- Solution properties - polymers are more vicious
- Mechanical properties - polymers are able to show elasticity and reversible
2
Q
Define configuration
A
Order of polymers due to its chemical bonds
3
Q
Name the three states of a amorphous polymers
A
- Glassy
- Rubbery
- Liquid
4
Q
What is the Tg value
A
- When polymer goes from glassy (hard) to rubbery (soft)
- Different value for each polymer
5
Q
Below Tg polymers are ..
Above Tg polymers are ..
A
Below they are hard and glassy
Above they are soft and elastic
6
Q
Describe the stages of dissolution of a polymer
A
- Diffusion of solvent molecules into the polymer
- Swollen gel
- Dissolution of the gel
7
Q
Describe the factors effecting solubility of a polymer
A
- Polymer-solvent interactions - chemical similarity more likely to solubilise
- Presence of cross links - don’t dissolve
- Molecular weight - smaller macromolecules dissolve faster
- Temperature
8
Q
Describe the four ways to make polymers
A
- Addition polymerisation - Breaking of C=C, typical one
- Ring open polymerisation - requires heat and catalyst
- Step growth polymerisation - forms polymer and biproduct mainly water
- Addition copolymerisation - made of two different monomers