Dendronized polyethylene glycols: Synthesis and characterization
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Novel hyperbranched-linear ABA block copolymers with a linear poly(ethylene glycol) (PEG) B part and a hyperbranched A part based on 2,2-bis(hydroxymethyl) propionic acid (bis-MPA) monomer were successfully synthesized. A pseudo one step condensation esterification was used to produce hyperbranched polymers from generation 2 (G2) to generation 7 (G7) with PEG (Mw = 2000, 6000, 20000 g/mol) core units. The synthesized polymers were characterized to determine degree of branching (DB), molecular weight (Mw,Mn), thermal properties (Tm, ΔH) and solubility. 1HNMR integrals confirmed that all generations for all three core PEG lengths were synthesized successfully. An increased intensity for the ester bonds and no residual carboxylic acid groups from bis-MPA monomer could be seen with IR spectroscopy. The hyperbranched polymers had a decreasing Tm and ΔH with increasing generation and a degree of branching between 40 and 60 % for all PEG lengths. PEG20K-Gx-OH was used to increase the viscosity of water. PEG20K-G2-OH had the highest intrinsic viscosity. Further functionalisation was performed to introduce allyl functionalities on the PEG6K-Gx-OH system which was then thiol-ene coupled with 3-mercapto propionic acid and cross-linked into gels using UV initiated thiol-ene chemistry. Hydrophobic and bulky benzylidene groups were attached to the..
Place, publisher, year, edition, pages
2012. , 32 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-156211OAI: oai:DiVA.org:kth-156211DiVA: diva2:765806