Polyglycidol as a scaffold for multifunctional polyethers

• Polyglycidol als Grundgerüst multifunktioneller Polyether

Marquardt, Fabian; Möller, Martin (Thesis advisor); Pich, Andrij (Thesis advisor)

Aachen (2018, 2019)
Dissertation / PhD Thesis

Dissertation, RWTH Aachen University, 2018

Abstract

In this thesis, various multifunctional polyglycidols are synthesized via post-polymerization modification protocols. Every functionalized polyglycidol is meticulously characterized by appropriate analytical methods in regard to its degree of functionalization, molecular weight, molecular weight distribution and purity. All syntheses are optimized to give maximum control on the degree of functionalization, high yields and pure products. The introduction of pendant diethyl phosphate groups into poly-glycidol is achieved by straightforward reaction of the hydroxymethyl side groups with diethyl chlorophosphate. The degree of function-alization is controlled by the ratio of hydroxymethyl groups attached to the polyether backbone to the organophosphorus reagent. Removal of one and both ethyl groups is accomplished by dealkylation with sodium iodide or bromotrimethylsilane, respectively. The synthesis of cationic/hydrophobic polyglycidols with various structures is presented. Functional polyethers are examined in regard to their antimicrobial properties against E. coli and S. aureus. Poly-glycidol with statistically distributed cationic and hydrophobic groups (cationic to hydrophobic balance 1:1) is compared to (a) polyglycidol with a hydrophilic modification at the cationic functionality, (b) polyglycidol with cationic as well as hydrophobic groups at every repeating unit, and (c) polyglycidol with a cationic to hydrophobic balance of 1:2. Structure-property relationships are presented. The usage of bio-based building blocks for polymer synthesis is investigated by functionalization of polyglycidol with homoserine lactone. The resulting polyethers with lactone groups in the side chains are converted to cationic/hydrophilic polymers by ring-opening reaction with 3-(dimethylamino)-1-propylamine, followed by quarter-nization with methyl iodide. The light-induced cross-linking of functional polyglycidol and its post-cross-linking modification are presented. Linear polyglycidol is first functionalized with a tertiary amine in a two-step reaction. The dimethylaminopropyl functional polyglycidol is cross-linked in an UV-light-induced reaction, using camphorquinone as a Type II photo-initiator. The cross-linked polyglycidol is further functionalized by quaternization with various organoiodine compounds. Aqueous dispersions of the cross-linked polymers are investigated in regard to their size and zeta potential. Dried polymer films are evaluated concerning the thermal transitions and chemical transformations.