EXAM ONE TOPICS
I. Introduction – Polymer Terms & Basic Concepts – slime demo: 1 lecture (slightly less)
II. Polymer Solutions
1. Thermodynamics of Polymer Solubility: polymer solubility parameters
2. Hydrodynamic volume and relation of viscosity
III. Molecular Weight (chapter 2) (slightly more than 2 lectures (80 min ones))
A. Calculation of Molecular Weight (Mn, Mw, polydispersity)
B. Determination of Molecular Weight
1. Intro – Absolute vs Secondary Methods
2. Osmotic Pressure
3. End Group Analysis
4. Light Scattering
5. Viscometry
6. GPC
IV. Polymer Morphology and Microstructure and Measurement
A. Introduction: Structure/Property Relationships and Structural Hierarchy
B. Polymer Microstructure
1. Repeat Unit Microstructure: Structural Isomers
2. Tacticity and Stereoregularity: (include cis/trans)
C. Individual Polymer Chain Conformations: Newman Projections, fully staggered
D. Polymer Morphology
1. Introduction: Crystalline and Amorphous: Effects on Physical Properties
2. Range of Morphologies: truly amorphous to highly crystalline – most plastics are semi-crystalline.
3. What influences amount of crystallinity
a. Thermodynamics: enthalpy and entropy
b. Structural factors (stereoregularity, size of side groups, IMF’s)
c. Processing: Drawing, annealing
4. Amorphous Polymers/Regions
a. Thermal Behavior
b. Glass-transition:
- viscoelastic nature of polymers
- polymer property questions (e.g. silly putty, etc.)
c. Influences on glass-transition
- molecular weight/branching
- amount of crystallinity
- structural features (hand-out)
5. Crystalline Polymers/Regions
a. Historical – Fringed-Micelle Model
b. Crystal Structure
- from dilute solution – single crystals
- from concentrated solution or melt – spherulites
- from melt w/ imposed stress – oriented lamella
c. Enhancing Crystallinity
- annealing and maximum rate of crystallization (= Tg + 2/3(Tm - Tg)
6. Elastomers
a. Chemically cross-linked elastomers
- Why do rubbers not show inelastic deformation (what is a typical
elasomer)
- Why does a stretched rubber-band contract upon heating?
b. Thermoplastic Elastomers. (physical crosslinking)
- SBS rubber (Tg’s of -58 and +92)
- Polyurethanes (hard-block and soft-block)
V Thermal Analysis
1. DSC/DTA
a. Differences – what are the techniques
b. Typical experiment – 10 mg w/ temp ramp of 10 °C/min from below Tg to above Tm.
b. DSC – description of typical thermogram features
d. Effect of thermal history
2. TGA – Thermogravimetric Analysis
a. The questions:
i. Structural what contributes to enhanced thermal stability?
b. Isothermal TGA vs “normal” TGA
c. Thermal Stability vs. Thermo-oxidative stability
VI Polymer Mechanical Properties and Processing
A. Polymer Mechanical Properties:
1. Mechanical Questions
2. Modulous
3. Stress/Strain Curves
4. Influences on Mechanical Properties: Temperature, Molecular Weight, Morphology