This course deals with the rheology of amorphous linear chain polymers. Rheology is the study of the deformation and flow of materials or objects. Polymer rheology is essential not only for the forming and processing processes of polymers to produce films, fibers, containers, etc. but also for academics because polymer rheology is related to the molecular motions of polymers.
This course aims to enable students to understand the dynamics of polymer chains over a wide range of time and space scales, from picoseconds to hundreds of hours, from 0.1 to 100 nm, through polymer rheology.
At the end of this course, students will be able to
1) Explain viscoelasticity of polymers phenomenologically and in molecular theory (polymer structures).
2) Explain rubber elasticity in molecular theory (polymer structures) and thermodynamics.
3) Have an understanding of time-temperature superposition principle, and based on this, produce and explain master curves.
viscoelasticity, rubber elasticity, reptation, Rouse model, time-temperature superposition principle, master curve
✔ Specialist skills | Intercultural skills | Communication skills | Critical thinking skills | Practical and/or problem-solving skills |
Each class is devoted to letting students reach the required learning from fundamentals. To allow students to get a good understanding of the course contents and practical applications, problems related to the contents of this course are provided.
Course schedule | Required learning | |
---|---|---|
Class 1 | 1-1. Outline of this course; 1-2. Stress and strain | Calculate the modulus and viscosity from the stress and strain on uniaxial elongation or simple shear deformation. |
Class 2 | 2-1. Entropy elasticity; 2-2. Rubber elasticity | Calculate the tension of rubber and the modulus of a polymer chain. Calculate the cross-linking density from the rubber modulus. |
Class 3 | 3-1. Viscoelasticity (relaxation elasticity); 3-2. Viscoelasticity (dynamic elasticity) | Explain phenomenological theory on stress relaxation and creep using mechanical models. Calculate the storage and loss moduli on applying oscillating strain to a viscoelastic model. |
Class 4 | 4-1. Measurement techniques and data processing; 4-2. Time-temperature superposition principle and the WLF equation | Explain the measurement techniques of polymer viscoelasticity. Understand the phenomenological theory on the time-temperature superposition principle. Explain the temperature dependence of relaxation time based on the free-volume theory and derive the Williams-Landel-Ferry equation. |
Class 5 | 5-1. Feature of polymer viscoelasticity and the molecular approach; 5-2. Boltzmann superposition principle | Derive the relationships between relaxation modulus and viscosity and complex modulus from Boltzmann's superposition principle. |
Class 6 | 6-1. Rouse model and tube model; 6-2. Understanding of master curves | Explain the frequency dependence of complex modulus in the glass transition and terminal flow regions based on the Rouse model. Explain the rubber plateau and molecular weight dependence of viscosity for entangled polymer melts based on the tube model. Estimate characteristic times from master curves to understand relaxation processes in polymer melts quantitatively. |
Class 7 | 7-1. Exercises; 7-2. Explanation on the excercises | Confirm one's understanding of the lecture content by practicing comprehensive exercises. |
This course expects students to review course content and solve exercises after each class.
Lecture materials will be distributed. The lecture content corresponds best to the reference book " Kiso Kobunshi Kagaku (Introduction to Polymer Science) 2nd ed."
The Society of Polymer Science, Japan, ed., Kiso Kobunshi Kagaku (Introduction to Polymer Science) 2nd ed., 2020, Tokyo: Tokyo Kagaku Dojin, ISBN :978-4-8079-0962-9 (Japanese)
M. Rubinstein and R. H. Colby, Polymer Physics, Oxford University Press, 2003. ISBN 0-19-852059-X
Grading of 50% will be based on the answers to the comprehensive exercises given in the seventh session and the remaining 50% on the exercises (or assignments) given in each class.
Students must have successfully completed Polymer Chemistry Basics or have equivalent knowledge.