1. Polymer Synthesis CHEM 421 Reading (Odian Book): Chapter 1-4, 1-5, 1-6

2. Polymer Synthesis CHEM 421 Polymer Parameters Chemical structure – Chemical composition and distribution – Sequence length and distribution Molecular weight and distribution Chain isomerism Morphology Topology Additives Cost

3. Polymer Synthesis CHEM 421 Chain Isomerism Regio-isomers Geometric isomers Stereo-isomers Conformational isomers

4. Polymer Synthesis CHEM 421 Conformational Isomers

5. Polymer Synthesis CHEM 421 Conformational Isomers - 180 - 120 - 60 0 +60 +120 +180 Energy (kcal/mol) 3.8 1.0 4.5

6. Polymer Synthesis CHEM 421 Amorphous Morphology Glass Transition Temperature

7. Polymer Synthesis CHEM 421

8. Polymer Synthesis CHEM 421 Copolymer Synthesis Tetrafluoroethylene (TFE) 2,2-bis(trifluoromethyl)- 4,5-difluoro-1,3-dioxole (PDD) Udo, M.; Resnick, P.; Kipp, B. ; DeSimone*, J.M. Macromolecules 2003, 36, 7107 50 100 150 200 250 300 350 5060708090100 T g in °C PDD in wt-%

9. Polymer Synthesis CHEM 421 Mechanical Properties Tensile strength – Resistance to stretching Compressive strength – The extent to which a sample can be compressed before it fails Flexural strength – Resistance to breaking or snapping when bent Impact strength – Measure of toughness, ability to withstand sudden impact Fatigue – Ability to withstand repeated tensile, flexural or compressive stress

10. Polymer Synthesis CHEM 421 Mechanical Properties Tensile stress (σ) – σ = F / A – dynes per square cm Tensile strain (ε) – ε = ΔL / L Tensile Modulus (E) – E = σ / ε

11. Polymer Synthesis CHEM 421

12. Polymer Synthesis CHEM 421 Processing of Amorphous Polymers T processing = ?

13. Polymer Synthesis CHEM 421 Symmetry Requirements for Crystallinity Syndiotactic Polystyrene Atactic Polystyrene T m = N/A T g = 105 °C T m = 270 °C T g = 105 °C

14. Polymer Synthesis CHEM 421 Cool a polymer melt… – Translational, rotational and vibrational motions decrease… – If certain symmetry elements are met, crystallization can take place just below T m – Continue to cool, long-range backbone segmental motion ceases at T g – Side groups and backbone para-phenylene still in motion below T g Processing of Semicrystalline Polymers

15. Polymer Synthesis CHEM 421 Trashcan T g = - 20 °C T m = 170 °C Isotactic Polypropylene

16. Polymer Synthesis CHEM 421 Processing of Semicrystalline Polymers T processing = ?

17. Polymer Synthesis CHEM 421 Processing of Semicrystalline Polymers

18. Polymer Synthesis CHEM 421 Differential Scanning Calorimetry

19. Polymer Synthesis CHEM 421 DSC of a Crystalline PolymerEndo

20. Polymer Synthesis CHEM 421 DSC of a Crystalline Polymer