UNESCO/IUPAC Lectures

Introduction to Polymer Chemistry

The interactive lecture Introduction to Polymer Chemistry aims to explanation of the basic concepts of macromolecular chemistry to students. The terms as a monomer, a polymer, a copolymer, types of copolymers, etc. will be explained. We will also focus on the mechanisms of polymerisation reactions, types of polymers and the basic properties of polymers - molar mass and its distribution, solubility and thermal transitions. Finally, some of the methods used to characterise polymers will be discussed.

Polymer Solutions in a Nutshell

Polymers & copolymers: isomerism.
Polymer solutions: structure/properties dichotomy; concentration regimes.
Extremely dilute solutions: shape, dimensions, and modeling of a flexible chain.
Thermodynamic of polymer solutions: Flory–Huggins equation.
Dilute solutions: osmotic pressure; second virial coefficient.
Two-parameter theory of polymer solutions: excluded volume effect; thermodynamic solvent quality.
Transport properties: diffusion coefficient& intrinsic viscosity.
Hydrodynamic interaction: rheology of polymer solutions.
Interaction of polymer solution with light: Rayleigh light scattering &quasielastic light scattering. Scaling arguments.

Molecular Weight and Dimensions of Polymers and Their Assemblies

Molecular weight (MW) and dimensions (MD) as a characteristic of polymers. A short review of classic methods used for the determination of MW and MD (colligative properties, viscometry, static and dynamic light scattering). Polydispersity as a specific feature of polymers – types of MW averages and distributions. Size exclusion chromatography (SEC) - the principle, detectors and data treatment. Field-flow fractionation. The principle of the mass spectrometry (MS). Limitations of the classic MS for application in polymer science. Development of MS for the MW measurement on intact macromolecules. MALDI–TOF MS: instrumentation and methods; sample preparation and requirements.

Controlled Polymerization of Vinyl Monomers

Methods of controlled polymerization leading to tailor-made polymers, random, block and graft copolymers, functionalized polymers, etc., with predetermined structure and architecture are briefly presented. The main attention is paid to anionic polymerization in the first part and to the modern methods of controlled radical polymerization in the second. For every method, basic chemistry is shortly given, ie., structure of corresponding initiator, reaction conditions, stability of growing centers, reaction mechanism and synthetic potential are discussed. More, the necessity of specific optimization the reaction conditions in every polymerization method with respect to monomer used and required product is mentioned and, finally, synthetic capabilities of the individual synthetic ways are compared.

Polymer Networks

General features of network formation and structure and their significance in science and applications are outlined. Network formation theories are grouped in three categories: (a) statistical theory of structure generation from units, (b) kinetic theories of evolution of molecular weight distribution, (c) computer simulation in space. Correlation of structural characteristics calculated theoretically with physical properties of the networks is explained.

Polymer Blends

The lecture briefly summarises problems typical of polymer blends. There is discussed miscibility of polymers from thermodynamics point of view and the difference between meaning of the expressions “miscibility” and “compatibility” is explained. The role of the interfacial tension is described and using of block and graft copolymers at compatibilization of polymer blends is discussed. Brief survey of the methods of blend preparation is given and evolution of its phase structure during melt mixing is discussed. The main reasons for changes in the phase structure of polymer blends at rest are described. Present state of knowledge of the relations between properties and the blend composition and phase structure is summarised. The most important commercial polymer blends are mentioned.

Morphology of Polymers

• Survey of polymer systems: homopolymers, copolymers, blends, composites...
• Examples: relation between morphology and properties
• Microscopy as a dominant method in the field of polymer morphology
• Intro to microscopic methods: LM(DIA,EPI..), SEM(SE,BSE..), TEM(BF,ED,EDX..)
• Examples of polymer structures/morphologies:
  • amorphous homopolymers: fracture surfaces, crack, craze, fracture lines...
  • semicrystalline polymers: lamellae, spherulites, crystal structure...
  • copolymers: microphase separation, possible morphologies...
  • polymer blends: macrophase separation, morphologies, properties...
  • polymer composites: micro vs. nanocomposites, morphology vs. properties...
• Supplements: polymer nanoparticles in solution, basic theory of EM ...

Nuclear Magnetic Resonance of Polymers: Modern Methods

Important structural and dynamic information about macromolecular systems bring a lot of one, two and multidimensional NMR experiments, especially those, which are based of polarization transfer and inverse detection. High resolution and high sensitivity of NMR experiments in liquids make it possible to determine the detail structure of complex polymer systems. On the other hand, recent improvement of solid-state NMR techniques made it possible to determine exactly interatomic distances and dihedral angles of insoluble solid organic and inorganic samples.

Key words: Solid-state NMR, liquid-state NMR, Polymers

Vibrational Spectroscopy of Polymers: Contemporary Methods

Theoretical background of infrared and Raman spectroscopy; normal mode calculations; photoacoustic spectroscopy; time-resolved spectroscopy; two-dimensional correlation spectroscopy; infrared and Raman microscopy and imaging; structure analysis of polymers: chain orientation, conformational structure, crystallinity, hydrogen bonding; analysis of polymer blends, complexes and aggregates.

Static Light Scattering

Basic design of a light scattering instrument. Contrast factor in light scattering – refractive index increment. Theoretical relations governing static light scattering and their simplification for practical usage – Zimm theory and diagram. Material properties that can be derived from static light scattering from polymer systems – molecular weight, size and interaction parameters. Examples of application of static light scattering to characterization of polymer systems.

Dynamic Light Scattering

Spectrum of quasielastically scattered light and correlation function. Broadening of spectrum of scattered light by diffusion and other dynamic processes in the system. Relation of diffusion and size of diffusing objects, Stokes-Einstein equation. Other dynamic processes influencing the spectrum of scattered light – rotation, internal modes, polymer chain dynamics. Calculation methods and polydispersity analysis - distribution of relaxation times and sizes.
Application of dynamic light scattering to several types of polymer systems: dilute, semidilute and concentrated solutions, gels, colloids, nanoparticle and microparticle systems, bulk polymers, copolymers and mixtures.

Surfaces and Interfaces of Polymers and Biomaterials

Biomaterial sciences and tissue engineering have recently focused on the design of biomimetic materials that are capable of eliciting specific cellular stimuli and directing new tissue formation mediated by biomolecular recognition, which can be manipulated by altering design parameters of the material surface. The lecture will track the trends in developing and applying new concepts in synthesis of smart bioresponsive polymer surfaces, with defined physico-chemical properties and known state of incorporated bioactive groups. At the same time, it will give an overview of advanced surface sensitive techniques, that we routinely use to gain detailed information on the properties of materials/surfaces used as biomaterials, scaffolds and sensors.

Electron Spin Resonance Spectroscopy

Theoretical part of the lecture is focused on a basis of the electron spin resonance spectroscopy (ESR) method, an origin of an ESR signal, parts of ESR spectrometer, ESR experiment, spectra and hyperfine effect. ESR techniques as a spin probe, a spin trapping and a spin label are presented.

π and σ - Conjugated Polymers

Preparation and modifications of conjugated polymers (polyacetylene, polythiophene, poly (p-phenylene vinylene), polyaniline, ladder polymers, polysilylenes). Electron delocalization in conjugated polymer backbone, electronic structure and excitations (polarons, solitons), doping by electron acceptors and donors.
Device applications: conductive polymers, electrochemical cells, gas and ion FET sensors, photoelectrical conversion in sollar cells, electroluminiscent and electrochromic displays, opto-electronic switches and memories, photonic applications (optical computing).

Polymer Rheology

Rheology describes flow behaviour of materials. In this lecture following topics are discussed:

• basic rheological quantities - viscosity and elasticity;
• specific features of rheological behaviour of polymers;
• experimental methods - capillary and rotational rheometry;
• extensional rheology;
• rheology as a powerful tool of structural analysis;
• rheology in polymer processing and quality control.

Polymer Membranes and Membrane Operations

The aim is to provide the participants with up-to-date survey and review of new membrane materials, new discoveries in the field of membrane phenomena and novel concepts in the design of membrane technologies and applications. The main attention has been devoted to relations between the chemical structure and transport properties of membranes allowing to learn more about the current status of and anticipated trends in areas of preparation new membrane polymer composition and their application. Key words: membrane operations, micro- , ultrafiltration, reverse osmosis, electrodialysis, membrane electrolysis, gas separation, pervaporation, membrane distillation, fuel cells, membrane reactors, membrane polymer synthesis, membrane preparation, polymer blends, polymer modifications, membrane module, membrane equipment, membrane technologies.

Biodegradable and Bioanalogous Polymers

Bioanalogous polymers can be defined as synthetic polymers that were either synthesised from building blocks of biological origin, or exhibit certain structural or functional features which would be otherwise typical for biopolymers. Biodegradability belong to such features. Biodegradable polymers are studied for biomedical as well as for technical applications. Mechanisms applicable in (bio)degradation of polymers differ between vinylics and condensation polymers. Synthesis and structural relationships of biodegradation of aliphatic polyesters and poly(amino acids), as typical classes of biodegradable polymers, are discussed and the examples of application of biodegradable polymers are given. Novel methods of polymer synthesis, based on using artificial gene constructs in modified biosynthetic pathways of genetically engineered micro-organisms to produce bioanalogous macromolecules with unique properties are introduced.

Polymer Systems for Controlled Release of Drugs

The use of synthetic macromolecules in the development of new drug release and drug delivery systems has been gaining importance in modern pharmaceutical industry. There are systems enabling controlled release of drugs in the living body only (oil droplets and ointments, polymer-coated systems, matrix-based systems, membrane systems and microparticle based systems). These systems are used in a preparation of dosage forms exhibiting protracting drug effect. There is another group of more sophisticated systems enabling specific delivery of drugs and their release only at the organ (cells) where therapeutic effect of the drug is required (targeted liposomes, micelles, soluble drug carriers, ADEPT systems). The lecture focuses on the structure, principle of action, chemical aspects of preparation and some biological properties and effects of the polymer drugs and polymer dosage forms mentioned above.

Key words: drug release, drug delivery, polymer drugs, drug carriers, dosage forms of drugs

Introduction to X-ray and Neutron Scattering Methods

Examples of the structures of polymeric systems are given. X-ray and neutron scattering methods rank among the most powerful tools for investigation of these structures. Both common principles and specific features of wide and small-angle scattering of X -rays and neutrons are discussed. Basic information on data interpretation and on the structure parameters provided by these techniques is presented. Examples of structure studies include time-resolved studies of crystallization and polymerization, multilayered micelles and linear polyelectrolytes.