Reading (Odian Book):

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Reading (Odian Book) Chapter 1-4, 1-5, 1-6
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Polymer Parameters

• Chemical structure
• Chemical composition and distribution
• Sequence length and distribution
• Molecular weight and distribution
• Chain isomerism
• Morphology
• Topology
• Additives
• Cost

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Chain Isomerism

• Regio-isomers
• Geometric isomers
• Stereo-isomers
• Conformational isomers

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Conformational Isomers
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Conformational Isomers
Energy (kcal/mol)
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Amorphous Morphology
Glass Transition Temperature
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(No Transcript)
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Copolymer Synthesis
Tetrafluoroethylene(TFE)
2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxole
(PDD)
350
300
250
in C
200
g
T
150
100
50
50
60
70
80
90
100
PDD in wt-
Udo, M. Resnick, P. Kipp, B. DeSimone, J.M.
Macromolecules 2003, 36, 7107
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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

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Mechanical Properties

• Tensile stress (s)
• s F / A
• dynes per square cm
• Tensile strain (e)
• e ?L / L
• Tensile Modulus (E)
• E s / e

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Processing of Amorphous Polymers
Tprocessing ?
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Symmetry Requirements forCrystallinity
Atactic Polystyrene
Tm N/A Tg 105 C
Syndiotactic Polystyrene
Tm 270 C Tg 105 C
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Processing of Semicrystalline Polymers

• Cool a polymer melt
• Translational, rotational and vibrational motions
  decrease
• If certain symmetry elements are met,
  crystallization can take place just below Tm
• Continue to cool, long-range backbone segmental
  motion ceases at Tg
• Side groups and backbone para-phenylene still in
  motion below Tg

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Trashcan
Isotactic Polypropylene
Tg - 20 C Tm 170 C
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Processing of Semicrystalline Polymers
Tprocessing ?
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Processing of Semicrystalline Polymers
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Differential Scanning Calorimetry
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DSC of a Crystalline Polymer
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DSC of a Crystalline Polymer