Presentation is loading. Please wait.

Presentation is loading. Please wait.

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

Similar presentations


Presentation on theme: "Polymer Synthesis CHEM 421 Reading (Odian Book): Chapter 1-4, 1-5, 1-6."— Presentation transcript:

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 Energy (kcal/mol)

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, 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


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

Similar presentations


Ads by Google