Unit:
Κατεύθυνση Επιστήμη Πολυμερών και Εφαρμογές τηςLibrary of the School of Science
Author:
Μπίτση Σπυριδούλα-Λήδα
Supervisors info:
Μαρίνος Πιτσικάλης Καθηγητής (επιβλέπων), Γεώργιος Σακελλαρίου Επίκουρος Καθηγητής, Ερμόλαος Ιατρού Καθηγητής
Original Title:
Ακροδραστικά ολιγομερή και κατά συστάδες συμπολυμερή που σχηματίζουν δεσμούς υδρογόνου. σύνθεση, χαρακτηρισμός, συσσωμάτωση σε καλό διαλύτη και ρεολογική συμπεριφορά
Translated title:
End-functionalized oligomers and diblock copolymers baring hydrogen bonds forming groups. Synthesis, characterization, associating behavior in good solvent and rheological behavior
Summary:
Three different series of very low molecular weight ω-functionalized
homopolymers PS-OH and diblock copolymers PS-b-PI-OH and PI-b-PS-OH were
synthesized by living anionic polymerization techniques. Samples of different
molecular weights, and/or compositions where obtain. Through the end-hydroxyl
group the functional unit 2-ureido-4-pyrimidone (UPy) was introduced in each
oligomer. The UPy group is strongly dimerized in a self-complementary array of
four cooperative hydrogen bonds. Each one of these series is composed from the
non functionalized copolymer, and the corresponding HO and the UPy-end
functionalized samples. All these polymers are well defined materials with
narrow molecular weight distribution and high homogeneity composition.
This new class of supramolecular, non-covalent polymers (in this case with
hydrogen bonds) is promising as their properties can be manipulated upon
changing the eternal conditions (temprature, solvent, shear forces and
concentration). The solution properties were studied by dynamic light
scattering (DLS), while the solid state properties were investigated by
differential scanning calorimetry (DSC), thermogravimetric (TGA) analysis and
reology. The hydrogen bonds dissociate in dilute solutions, polar solvents
and/or high temperatures. In high concentrations, apolar solvents and/or low
temperatures they form aggregates.
Keywords:
Anionic polymerization, Hydrogen bonds, Oligomers, Diblock copolymers
