dr. Felix Plamper : Architectural Effects on Polymer-Polymer Interactions
|Wanneer:||do 08-05-2014 13:45 - 14:45|
As a main point of interest, we investigate (inter)polymer complexation in aqueous solution / dispersion. As an example, the influence of the monomer sequence on the thermoresponsive properties of copolymers of N,N-diethyl acrylamide (DEAAM) and N-isopropyl acrylamide (NIPAM) is addressed. Only the close proximity between both units (as in a statistical copolymer) allow efficient hydrogen bonding between DEAAM and NIPAM, leading to a synergistic depression of the cloudpoints.
The close proximity between different monomer units is also vital for triggering the complexation between other weakly interacting polymers. Here we discuss poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(propylene oxide) (PPO), which is a thermoresponsive polymer couple exhibiting bulk miscibility. The influence of macromolecular architecture on their interaction in aqueous media is investigated and pronounced differences between miktoarm stars and linear copolymers were found.
Finally we regard electrostatic attraction: E.g. interpolyelectrolyte complex (IPEC) formation between linear polyanions and cationic, branched miktoarm stars is beneficial for the spontaneous formation of polymersomes as a very rare IPEC morphology. Also Janus-like IPEC can be generated. Besides the IPEC formation, the complexation with light- and redox-sensitive, multivalent counterions is addressed.