Amphiphilic Polymer Conetworks Based on End Group Cross-Linked Poly(2-oxazoline) Homo- and Triblock Copolymers

Novel amphiphilic polymer conetworks (APCNs) were prepared via,, end group cross-linking. To this end, poly(2-methyloxazoline) (PMOx), poly(2-butyloxazoline) (PBuOx), and the triblock copolymers PMOx-b-PBuOx-b-PMOx were synthesized by cationic ring-opening polymerization in varying block lengths and telechelically modified with N,N-bis(2-aminoethyl)ethylendiamine (TREN). First the cross-linking with 1,4-dibromo-2-butene (DBB) was established for the homopolymers. The swelling of those matches the theoretical value for full cross-linking, indicating that in this way near perfect networks could be obtained. Mixtures of the homopolymers and the triblock copolymers were cross-linked with DBB to give APCNs with similar polymer segments but different network topology. AFM showed that all formed APCNs are nanophase separated with slight structural differences in the nanostructures when comparing conetworks with similar composition but different cross-linking strategies. The more drastic difference between APCNs of different topologies was found in their swelling characteristics, which clearly proves the influence of conetwork structure on their properties.