Advanced Manufacturing (Lee) Flashcards
1
Q
What are 2 types of polymerisation?
A
1) step growth
2) chain growth
2
Q
What is step-growth?
A
For monomers w/ functional groups
Fast reaction
Small molecule is removed during reaction
3
Q
What is chain growth ?
A
Converts monomers by opening of double bond w/initiator
4
Q
Describe TP
A
- Can be linear or branched
- held together by weak secondary forces i.e. van der waals, H bonds, dipole-dipole
- flows upon hearing
- high viscosity in melt state
5
Q
How do you find the Mw of a TP? Why can’t you find Mw of TS this way?
A
Gel permeation/Size Exclusion Chromatography (GPC/SEC)
∵ ≠ dissolve TS ∴ won’t work
6
Q
Why do short chains come out last in GPC/SEC?
A
∵ goes into the pores
