Topic: Functional Polymers from Amino Acids and Sugars
Speaker: Prof. Helmut Schlaad, Johannes Gutenberg-University Mainz, Germany
Time: 15:00 p.m., Sep. 5, 2016
Venue: Conference Room 331, Building 25, Wushan Campus
Abstract:
This lecture gives an overview of our recent research activities on functional polymers made from amino acids and sugars. Special focus is put on three topics:
(1) Statistical copolypeptides based on allylglycine and -benzyl-l-glutamate were prepared by ring-opening copolymerization of corresponding amino acid N-carboxyanhydrides. The allylglycine units were functionalized with 2,3,4,6-tetra-O-acetyl-1-thio--d-glucopyranose applying thiol-ene “click” photochemistry. Removal of the protecting groups yielded glycosylated poly(l-glutamate)s, which were capable of recognizing proteins (specific carbohydrate-lectin interactions) and changing solution properties (ionization and conformation) in dependence of solution pH.
(2) Poly(-benzyl-l-glutamate-co-allylglycine) formed organogels at < 2% w/v in toluene, tetrahydrofuran, or 1,4-dioxane, assisted by UV-crosslinking with dithiol. Debenzylation of dioxane gels yielded highly absorbent and pH-responsive poly(l-glutamate) hydrogels, which are attractive materials for biomedical applications.
(3) Multi-heterofunctional poly(ester-disulfide-alkene)s were prepared by metathesis polymerization of l-cystine based macrocycles. Monomer conversion reached ~80% in equilibrium and the produced polymers exhibited high apparent molar masses (Mwapp) of up to 80 kDa and dispersities (Ð) of ~2. The polymers can be further functionalized with acid anhydrides and degraded by reductive cleavage of the main-chain disulfide.