Characterization of Polymeric Materials

Basic concepts of chemical, physical, and mechanical characterization techniques, with special focus on polymeric bulk and porous materials.

Jose Alejandro Heredia-Guerrero jose.guerrero@iit.it

Luca Ceseracciu luca.ceseracciu@iit.it

Javier Pinto Sanz.Pinto@iit.it

Nanophysics Department, Istituto Italiano di Tecnologia

Bulk and porous polymers are ubiquitous materials in multiple fields of industry and research. Their extensive range of properties facilitates their use in very diverse applications.

In this PhD course, we show the main techniques and methodologies in the characterization of their useful properties as materials. This characterization includes the determination of the chemical composition and structure and the potential reactivity as well as the determination of the polymeric structure and its implication on the final properties. In this context, the size and the form of the macromolecules are key parameter.

Furthermore, the application range of polymeric materials can be extended introducing a gaseous phase (porosity), which induces significant modifications on the physical properties of the polymeric samples, controlled by the main parameters of this gaseous phase.

Through a combination of mechanical characterization techniques, it is possible to give a comprehensive description of the deformation mechanisms of polymers, from elastic deformation to plasticity and fracture, taking into account the influence of factors such as temperature, time and scale. The mechanical parameters will include classical uni-axialstress-strain behavior, toughness and fracture toughness, creep, dynamic behavior, hardness, with special focus on nano-indentation.

The objective of this course is to describe the experimental techniques used for these characterizations. The approach is very applied, starting from the theory for each technique and leading to practical strategies to the test design and interpretation of results.

Chemical characterization: main spectroscopy techniques, such us UV/VIS, infrared and

Raman spectroscopies and nuclear magnetic resonance;

Structural characterization: the order of the macromolecules in terms of amorphous and crystalline domains will be depicted. Standard methods for the determination of the polymeric structures will be described.

Determination of molecular weight of polymers: the number and weight average molecular weight and the distribution of molecular weights will be explained and the usual methodologies for their determination will be described.

Porous polymers characterization: a brief description of porous polymers production processes and main characteristics will be provided in order to understand the concepts and techniques employed in the course: determination of the main parameters of the porous structure, gas/liquid pycnometry, radioscopy techniques, influence of the porosity on the physical properties of the porous polymers, in-situ study of the processes inducing the

porosity.

Mechanical behavior of polymers: deformation mechanisms, uni-axial testing, hardness, toughness measurements

Nano-indentation: fundamentals, analysis methods, practical applications

The examination consists in a written test.

- Physical properties of polymers handbook. James E. Mark. Springer.

- Polymer Characterization: Physical Techniques, 2nd Edition. Dan Campbell, Richard A. Pethrick, Jim R. White. CRC Press.

- Cellular Solids: Structure and Properties, 2 nd Edition. L. J. Gibson and M. F. Ashby. Cambridge University Press.

- Nanoindentation, 2 nd ed., A. C. Fischer-Cripps, Springer

Course date : April 2017