Advanced Chemistry and Physics of Polymers

A.Y. 2021/2022
6
Max ECTS
48
Overall hours
SSD
CHIM/04
Language
English
Learning objectives
The course is intended for students who have attended fundamental courses in chemistry or industrial chemistry and who plan to acquire advanced knowledge on modern techniques of synthesis and characterization of polymers. The course is preparatory to monographic or specialized courses in polymer science and technology.
Expected learning outcomes
At the end of the course, the Student will be able to:
1. Define the basic concepts and terms essential for the study of polymer science.
2. Identify the classes of polymerizable monomers with the synthetic mechanisms described.
3. Describe the fundamental mechanisms used for the synthesis of complex and controlled polymer architectures, in particular using living polymerization mechanisms.
4. Understand the different characteristics of the amorphous and crystalline solid state of polymers and the influence of the transition temperatures typical of these states on the physical properties and workability of the polymers.
5. Interpret simple calorimetric traces of the DSC type, identifying melting and glass transition temperatures and physical aging phenomena.
6. Interpret simple thermogravimetric (TGA) plots to determine the thermal stability of polymers and the composition of polymer blends.
7. Interpret simple MALDI-TOF spectra for the identification of the distribution of the molecular masses of the polymers and their structural details.
8. Interpret simple SEC spectra. For the determination of the molecular weights of polymers.
9. Classify the rheological curves of polymers.
10. Know the basic definitions and constitutive equations that describe the viscoelastic behavior of polymers.
Course syllabus and organization

Single session

Responsible
Course syllabus
1. Introduction to polymer science: general definitions and classifications of polymers. Plastics and their relevance. Natural, synthetic and artificial, inorganic polymers. Statistical, alternating, block and graft copolymers and their relevance. Geometric isomerism, configurations and conformations of polymers. Molecular weight of polymers: molecular weight distribution; numerical and weighted average values; polydispersity.
2. Step-wise polymerization mechanism: polymerizable monomers. Dependence of the polymerization degree on the reaction parameters in the absence and in the presence of monofunctional monomers; time dependence of the polymerization degree; number and weight distribution functions of molecular weights. Synthesis of cross-linked polymers.
3. Radical polymerization mechanism: polymerizable monomers. General process features: rapid, exothermic reactions; main reaction steps: initiation, propagation and termination, chain transfer. Dependence of the average polymerization degree on the reaction parameters. Chain transfer: Mayo-Lewis equation. Inhibition and retardation reactions. Self-acceleration effect. Depolymerization reaction and "ceiling temperature".
4. Polymerization with ionic mechanisms: polymerizable monomers; initiators for cationic and anionic mechanisms; solvent dependence of the polymerization rate. Cationic mechanism: chain transfer step; temperature effect on the reaction products. Anionic mechanism: living polymerization.
5. Stereospecific polymerization mechanisms: polymerizable monomers. Composition and structure of Ziegler/Natta catalysts and their general reactivity. Polymerization mechanism through poly-insertion: monometallic and bimetallic mechanism. Ziegler/Natta iso- and syndiospecific catalysts. Supported catalysts. Catalysts of higher generations: use of the third component. Kinetics of polymerization. Termination and chain transfer steps. Metallocenes: Composition and structure of metallocene catalysts. Effect of methylaluminum oxanes (MAO). Polymerization through poly-insertion mechanism. Stereospecific control: iso- and syndiospecific catalysts. Effect of the catalyst symmetry.
6. Controlled radical polymerization mechanisms (CRP): nitroxide mediated polymerization (NMP); ATP (atom transfer polymerization); reversible addition-fragmentation transfer (RAFT) polymerization .
7. Ring-opening polymerization: polymerizable monomers. Classification of the initiators: electrophilic and nucleophile ring opening. Polymers of industrial interest.
8. Molecular weight analysis: solution properties of polymers. Size exclusion chromatography light scattering offline and online. MALDI-TOF mass analysis.
9. Thermal analysis of polymers: Amorphous and crystalline state in polymers. Crystalline polymers: requirements for achieving crystallinity; semi-crystalline polymers; morphology of polymeric crystals (lamellae and spherulites. Amorphous polymers: glass transition temperature, Tg, as a non-thermodynamic transition. Crystallization rate. Scanning calorimetric analysis (DSC): classification of existing instruments and operating principle. Analysis of glass transition temperature and melting temperature. Examples of DSC thermograms. Dependency of the shape of the thermograms from the rate of heating and/or cooling. Annealing and physical aging.
10. Thermogravimetric analysis: operating principle and application to the study of thermal and thermo-oxidative decomposition of polymers.
11. Rheology of polymers: general definitions and concept of viscoelasticity. Flow curves and flow regimes. Dependence of viscosity on temperature, time, molecular weight, deformation rate, shear stress.
12. Introduction to the mechanical and dynamic mechanical properties of polymers.
Prerequisites for admission
Basic knowledge of organic chemistry, physical chemistry and of polymer synthesis.
Teaching methods
Lectures with the aid of slides and audio-visual systems (video).
Teaching Resources
1. Instructor notes, both as Power Pont files and videos available at https://eranuccipc.ariel.ctu.unimi.it/
2. "Principles of polymerization" Geroge Odian, Wiley.
3. Pertinent articles or monographs provided by the instructor available at https://eranuccipc.ariel.ctu.unimi.it/.
Assessment methods and Criteria
The exam will consist of an oral interview lasting 30-35 minutes. The exam calendar will be published on the University intranet.
The score will vary between 18 and 30 out of 30 and will be proportional to the number of correct answers.
The oral interview will aim to ascertain the achievement of the expected learning outcomes in terms of knowledge and understanding. The evaluation criteria will focus on the student's ability to answer open short answer questions (DRAB) on all topics covered in the course.

· General definitions and introductory concepts of polymer chemistry.
· Description of the different reaction mechanisms taken into consideration during the course with particular emphaysis on the definition of the families of polymerizable monomers, the trend of the degree of polymerization with the conversion, the control of molecular weights, the control of the polydispersity of molecular weights in particular in living polymerizations and in the mechanisms of controlled radical polymerization.
· Differences and similarities between polymerization with conventional radicals and those with controlled radical mechanisms.
· Differences and similarities between the various types of stereospecific polymerization.
· Differences and similarities between polymerizations with a ring-opening mechanism and those with a step and chain mechanism.
· Introduction to the amorphous solid state and to the crystalline solid state and definition of the main transition temperatures.
· Thermal properties of polymers: application of DSC and MDSC calorimetric analyzes, their differences and competitive advantages.
· Thermal properties of polymers: application of traditional and high-performance TGA analyzes.
· Determination of the molecular weights of polymers: SEC chromatographic analysis, MALDI-TOF mass analysis and light scattering measurements.
· Rheology of polymers: basic definitions and characteristics of the viscoelastic behavior of polymers.
· Mechanical and dynamic mechanical properties of polymers.
CHIM/04 - INDUSTRIAL CHEMISTRY - University credits: 6
Lessons: 48 hours
Professor: Ranucci Elisabetta
Professor(s)
Reception:
Free time, preferable appointment by e-mail
Office 3rd floor Department of Chemistry