Unit POLYMER TECHNOLOGY

Course
Sustainable materials and processes engineering
Study-unit Code
A002468
Curriculum
In all curricula
Teacher
Luigi Torre
CFU
12
Course Regulation
Coorte 2021
Offered
2021/22
Learning activities
Caratterizzante
Area
Discipline dell'ingegneria
Academic discipline
ING-IND/22
Type of study-unit
Obbligatorio (Required)
Type of learning activities
Attività formativa monodisciplinare
Language of instruction
Italian
Contents
• Synthesis of polymers and polymerization reactions
• Physic-chemical properties of polymers,
• Mechanical properties and viscoelasticity.
• Absorption and solubility, degradation and stabilization of polymers.
• Introduction to rheology and rheometry of melted polymers.
• Polymer processing techniques.
• Recycling of polymeric materials
Reference texts
Fondamenti di struttura, proprietà e tecnologia dei polimeri a cura di Enrico Pedemonte http://nuovacultura.it/catalogo/fondamenti-struttura-proprieta-tecnologia-dei-polimeri/
R. J. Young and P.A. Lowel: Indroduction to Polymers. Chapman ed.
F. Rodriguez: “Principles of Polymer Systems” Mc Graw Hill
Educational objectives
To provide the student with the fundamentals of the polymer science, starting from synthesis of polymers up to processing, reuse and recycling. At the end of the course the student will have acquired knowledge, which will make him able to understand the criteria used in the selection of the most suitable polymeric material for a given application; he will have the tools to understand the behavior of any product made out of polymers as a function of temperature and in different environmental conditions; he will know and will be able to compare the main production processes and face the problems related, finally he will have the fundamentals of polymer recycling processes. The student will therefore be able to understand how polymeric materials behave during their exercise, he will have the basis for dealing with any problems that occur in the industrial environment, both in terms of processing and in terms of the physical or mechanical behavior of a polymeric product.
Prerequisites
Material Science and Technology
Teaching methods
Frontal Class, e laboratory visits.
Learning verification modality
Homework and two miderm test or one final test, oral examination with the presentation of a little thesis.
Extended program
Introduction. Structure, and classification: thermoplastic polymers, thermosetting polymers, homo and co-polymers, molecular weight and molecular weight distribution. commodity polymers, techno polymers, biopolymers, and blends.
Synthesis of polymers.
Step polymerization: Introduction, reaction mechanism. Carothers theory, Flory theory (most probable distribution), kinetics, poly-condensation: Carothers gelling theory and Flory gelling theory.
Chain polymerization: Reaction mechanism, kinetics, activation energy, average degree of polymerization, self-acceleration, chain transfer, effects of temperature, inhibition and delay.
Copolymerization: Classification of copolymers. Composition equation of a copolymer, fa-Fa plot. Azeotrope blend. Determination of the amount of unreacted monomer.
Viscoelasticity: Definitions. Variation of stress and strain over time. Maxwell model; Voigt (or Kelvin) model; Standard Linear Solid. Boltzman superposition principle.
Viscoelasticity: Dynamic-Mechanical tests. Torsion pendulum. Frequency dependence of viscoelastic behavior. Transitions and polymeric structures.
Rheology and Rheometry: rheological behavior of polymers viscosity measurement of polymer melts, time temperature superposition principle, WLF equation.
Structure: Polymer crystals. Determination of the crystal structure. Semi-crystalline polymers, spherulites, degree of crystallinity, crystal thickness and orientation, thermodynamics of crystallization and molecular mechanism, Hoffman theory. Avrami law. Melting, factors affecting the meting temperature
Structure. Amorphous polymers. Free volume theory and glass transition, Gordon-Taylor equation for copolymers. Dependence of Tg on the chemical structure, elastomers
Characterization of Polymers: thermal analysis Thermogravimetry, calorimetry, dilatometry, examples and equipment
Mechanical properties: “Yield” of polymers phenomenology, necking, pressure-dependent yield criteria. Dependence on strain rate and temperature
Solubility and absorption of polymers: Fickian diffusion and Case II, solubility criteria for polymeric materials, solubility parameter, Flory Huggings theory.
Processing. Production processes of polymeric materials, Extrusion and co-extrusion basic concepts and operation. Fiber spinning and Filming: equipment and process modeling examples. Injection molding: principles of operation and main industrial problems.
Recycling and reuse of polymeric materials, problems and main techniques.
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