PC Painter and MM Coleman
Fundamentals of Polymer Science
(2nd Edition, CRC Press)

Chapter 7

Concepts that you must know:
  1. Review -also from previous courses material- the following: phase transition, first order phase transition, types of intermolecular interactions (van der Walls, electrostatic, dipole-dipole, hydrogen bonding)
  2. Bond rotations, bond rotation potential, trans / gauche for sp3 carbon.
  3. Crystalline materials and X-Ray Diffraction. Crystal unit cell for small molecules and polymers. Polymeric crystals: fringed micelles, spherulites, chain folds, tie molecules.
  4. Polymer crystals from solution, from the melt, shear-induced.
  1. * Go through the 'random walk' derivations of 7.D, esp. the relations on the mean square end-to-end distance (eq. 7.14) and the associated probability distribution P(R) or W(R) (eq. 7.23, fig. 7.14).
  2. * Explain rubber elasticity based on the concept of end-to-end probability distribution W(R).
  3. * Go through study question 5 (pg. 256), esp. on how mechanical properties and optical transparency depend on the polymer state.
Interactive Module:
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  1. Start by a 1 step RW (set the step to a large number, e.g. 90) and plot 150 RWs. Notice how the ends are arranged.
    Change to 2 steps and comment on how the distribution of ends changes. How many runs do you need to start approaching the statistical average of the mean square end-to-end ?
  2. Make 900 RW of 2 steps and comment on the existence of RWs that end near the starting point (i.e. end-to-end close to zero)
  3. Choose 100 steps of RW (set the step to a small number, e.g. 10) and make 10, 20, 30, ..., 100 RWs. Comment on the RW end distribution and the running mean square end-to-end average.
  4. Choose a small step length (e.g. 5) and make increasingly longer RWs: 10, 20, 100, 200, ..., 999. Is RW an effective trajecory to get away from the starting point? Comment on how your qualitative observation can be quantified through the average mean square end-to-end distance.