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Identifier

000451448

Title

Rheological studies of linear and nonlinear polymer melts across a range of molar masses

Alternative Title

Ρεολογικές μελέτες γραμμικών και μη-γραμμικών πολυμερικών τηγμάτων σε εύρος μοριακών μαζών

Author

Πεπονάκη, Αικατερίνη Ζωή

Thesis advisor

Βλασσόπουλος, Δημήτριος

Reviewer

Πετεκίδης, Γεώργιος
Loppinet, Benoit

Abstract

Understanding the properties of soft matter is the key for designing new materials that embrace a vast variety of products. Thus, it is important to start with fundamental research questions in order to lay the foundation for understanding more complex systems. In this work a systematic rheological study on amorphous, synthetic polymers i.e., model systems, will be percent. Polymeric properties strongly depend on the architecture as well as on the molar mass. Linear polymer chains are the most extensively studied systems and there are numerous studies on their conformational and dynamical properties in polymer melts. But still, some aspects are not fully explained. Similar, branched macromolecules have been under investigation though years, albeit their behavior is not fully explored, especially at the array limits of their grafting density and branch length. The main aspect that affects these architectures is the presence of chain ends. The cyclic polymers, due to their lack of ends, exhibit unique characteristics. Although they are still fundamentally unexplored. In addition, for all the architectures mentioned, the majority of experimental works have been focused on the long chains, while the transition between the meaning of short and long chain is still blurry. In this work we investigate experimentally the linear and nonlinear shear rheology of various polymeric architectures, mainly in the unentangled regime and the transition to entangled one. A comparison between the presented data and the literature are also included. The experimental difficulties that arise during the investigation of such samples are discussed in detail. This work aims to identify the dynamics of those architectures, in order to be able to describe and predict their associated physical properties and eventually to address and fill the gaps in the characterization map of polymers.

Language

English

Subject

Characterization techniques

Polymer physics

Polymers

Τεχνικές χαρακτηρισμού

Φυσική πολυμερών

Issue date

2022-07-29

Collection

School/Department--School of Sciences and Engineering--Department of Materials Science and Technology--Post-graduate theses