Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

Semi-Crystalline Helical Structure Chain Folding

Semi-Crystalline Fibrillar Growth

Spherulitic, shish-kabob, epitaxial surface nucleation, Crystalline Orientation

Lamellar Orientation Macroscopic Orientation

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Rigid, semi-Rigid, Flexible Polymer Chains

On melting the entropy gain is small because the crystallizing units are chemically bound. The random coil state is seen classically as the highest entropy state. For rigid polymers the ground state may be a lower entropy state.

Kevlar

Polythiophene

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

Paul Phillips 1990 Review Tacticity

Tacticity governs the helical structure

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Chain Folding and Crystallization

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

n-alkane boiling and melting points

“n”

Boiling (top) or Melting (bottom) Point

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

“Crystals act like crosslinks in rubber” P. Phillips 1990

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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http://www.eng.uc.edu/~gbeaucag/Classes/MorphologyofComplexMaterials/Chapter2html/Chapter2.html

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

Solution Crystallization

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Why do Chains Fold?

http://scholar.lib.vt.edu/theses/available/etd-051799-162256/unrestricted/polyimide2.pdf

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For an infinite crystal V/S is very large and we can ignore the surface At the equilibrium melting point ΔG = 0 so:

substituting in the first equation,

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For a lamellar crystal S is 2R² and V is tR²

At a pseudo-equilibrium point where the crystal has a finite thickness of t and a depressed melting point, T

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or

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Hoffman-Weeks Plot

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

Diffusion of impurities versus growth rate of crystallization front J = -D dc/dx for flux of impurities

G = linear growth rate of crystal D/G = δ, the Keith-Padden δ-parameter

This determines the coarseness of the spherulite (lateral size)

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Hoffman-Lauritzen Secondary Nucleation Theory

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Add a first stem, then subsequent stems.

First stem and subsequent stems add 2b0σl and b0σl

To the free energy (cost to make a surface)

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http://scholar.lib.vt.edu/theses/available/etd-051799-162256/unrestricted/polyimide2.pdf First stem:

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Primary Nucleation

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Spherulites

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies and their Hierarchical Morphologies

Non Crystallographic Branching

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Semi-Crystalline Polymer Morphologies

and their Hierarchical Morphologies

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Spherulitic Growth Rate

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Avrami Equation

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Avrami Equation

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Avrami Equation

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Avrami Equation

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Avrami Equation

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