• After a brief review of fluid mechanics, the main concepts of polymer melt rheology are studied. Experimental methods for linear viscoelasticity, including stress relaxation, creep and oscillatory shear, are understood and correlated using Boltzmann superposition. Molecular models of polymer rheology are developed to understand how rheology changes with molecular weight, polydispersity and molecular architecture. Polymers subjected to strong flows exhibit nonlinear viscoelasticity as a result of stretching molecules. The understanding of polymer melt rheology is then utilized to introduce polymer melt processing. Processes such as extrusion, injection molding, blow molding, thermoforming, profile extrusion, and rotational molding are analyzed using the concepts of fluid mechanics and rheology that were previously developed. This analysis includes a brief exposure to computer modeling of injection molding.

• The course addresses scientific and engineering process design issues through study of the interrelationships between polymer molecular architecture, rheological properties and processing performance. Emphasis is on developing the intuition of students for how changes in molecular structure affect rheology and how those rheological changes in turn alter the design of processing for that polymer.

• Formerly designated PLMSE 442; this is a required course for the Polymer Science and Engineering Option; an elective course for other options.

• This course is offered annually, in the fall semester, in the Department of Materials Science and Engineering

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• Student will solve simple flow problems that assume isothermal and Newtonian liquids.

• Students will generalize basic knowledge of the fundamental principles underlying fluid mechanics, rheology, and polymer melt processing.

• Students will employ calculation skills and practical problem solving for industrial utility of classroom learning through weekly homework assignments.

• Students will interpret computer-aided design and simulation tools for polymer processing using the UNIX undergraduate computer lab with commercial software.

• Students will build up a molecular intuition about rheological properties of polymers and how they behave in processing.

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• MatSE443 (Introduction to Polymers), CALCULUS, and PHYSICS

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• J. M. Dealy and K. F. Wissbrun, Melt Rheology and its Role in Plastics Processing, Kluwer Academic (1999) ISBN 0 412 7391 0

• Two Hour Reserve Books (Deike Library)

  RHEOLOGY

  F. N. Cogswell, Polymer Melt Rheology: a Guide for Industrial Practice (1997).

  J. D. Ferry, Viscoelastic Properties of Polymers (1980).

  C. W. Macosko, Rheology (1994).

  F. A. Morrison, Understanding Rheology (2001).

  R. W. Whorlow, Rheological Techniques (1992).

  PROCESSING

  A. W. Birley, B. Haworth and J. Batchelor, Physics of Plastics:

  Processing, Properties and Materials Engineering (1992).

  S. Middleman, Fundamentals of Polymer Processing (1977).

  D. H. Morton-Jones, Polymer Processing (1989).

  T. A. Osswald, Polymer Processing Fundamentals (1998).

  Z. Tadmor and I. Klein, Engineering Principles of Plasticating Extrusion (1970).

Back to Syllabus

• Basic fluid mechanics, including stress and strain tensors, viscosity, and modulus.

• Conservation of mass and momentum transfer.

• Solving simple flow problems using the Navier-Stokes equations.

• Linear viscoelasticity of polymer melts, including stress relaxation, crop, oscillatory shear, and Boltzmann superposition.

• Non-linear viscoelasticity of polymer melts, including steady shear, normal stresses, die swell, and transient flows.

• Molecular models for rheology including bead-spring models and tube models for entanglement effects.

• Rheometry, including rotational rheometers, capillary and slit rheometers, and the proper design of rheology experiments.

• Extrusion, including calculating pressures and flow rates, mixing, screw design, die design, and estimating die swell.

• Injection molding, including simple estimations for runner balancing, and computer-aided mold design using Mold flow/C-Mold.

• Other polymer processing operations, including compression molding, blow molding, rotational molding, pipe extrusion, sheet extrusion, thermoforming, fiber spinning, profile extrusion, and solvent coating.

Stress

Strain

Tensors

Viscosity

Modulus

Conservation of mass

Momentum transfer

Navier-Stokes equations

Reynolds number 

Creeping flow

Poiseuille flow 

Couette flow

Dimensional analysis and scaling

Linear viscoelasticity

Stress relaxation

Oscillatory shear 

Creep and creep recovery

Boltzmann superposition

Nonlinear viscoelasticity

Steady shear

Normal stresses

Transient shear flows 

Rotational rheometers

Capillary/slit rheometers

Simple nonlinear viscosity models

Time-temperature superposition

Molecular models

Entanglement

Concentration effects

Crosslinking reactions (gelation)

Extensional flows

Extrusion

Pumping

Mixing

Screw design

Die design

Die swell

Injection molding

Mold filling

Computer-aided mold design

Weld lines

Compression molding

Sheet extrusion

Thermoforming

Pipe extrusion

Blow molding

Film blowing

Rotational molding

Fiber spinning

Profile extrusion

Coating

Reaction injection molding

01

 Basics

17

 Injection Molding - 1

02

 Fluid Models

18

 Injection Molding - 2

03

 Tensors

19

 Injection Molding - 3

04

 Flow In Varied Geometries

20

 Extrusion - 1

05

 Linear Viscoelasticity

21

 Extrusion - 2

06

 Steady Shear Start-Up Cessation

22

 Residence Time

07

 Oscillatory Shear

23

 Dimensional Analysis

08

 Rouse Model

24

 Sheet Extrusion

09

 Reptation

25

 Fibers Film

10

 Time Temper Superposition

26

 Profile Extrusion

11

 Non-linear Viscoelasticity - 1

27

 Blow Molding

12

 Non-linear Viscoelasticity - 2

28

 Rotational Molding

13

 Rheometry - 1

29

 Thermoset Molding

14

 Rheometry - 2

30

 Reaction Injection Molding

15

 Rheometry - 3

31

 Coating Thin Films

16

 Molecular Structure effects

32

 More Coating

Friday, September 8

Homework #1 due

Friday, September 15

Homework #2 due

Friday, September 22

Exam #1

Friday, September 29

Homework #3 due

Friday, October 6

Homework #4 due

Friday, October 13

Homework #5 due

Friday, October 20

Homework #6 due

Friday, October 27

Exam #2

Friday, November 3

Homework #7 due

Friday, November 10

Homework #8 due

Friday, November 17

Homework #9 due

Friday, November 24

Exam #3

Friday, December 8

Homework #10 due last day of classes

Friday, December 15

Final Exams

25% Homework

25% Exam #1

25% Exam #2

25% Exam #3

25% Final Exam

We drop the lowest exam score relative to the mean.

• Students are encouraged to work jointly to complete homework assignments (although each student must hand in their own individual homework).

• Students are also encouraged to seek homework help from their professor.

• Students must work independently on all examinations.