6533b855fe1ef96bd12b072d

RESEARCH PRODUCT

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Markus AntoniettiPeter LindnerHans SillescuJoachim Heyne

subject

chemistry.chemical_classificationchemistry.chemical_compoundEnd-groupTelechelic polymerAnionic addition polymerizationchemistryDynamic light scatteringZwitterionPolymer chemistryPolymerPolystyreneSmall-angle neutron scattering

description

Telechelic α,ω-macrozwitterions — narrowly distributed polystyrene chains oppositely charged at each end — were synthesized via anionic polymerization using direct functionalization with the initiator and the termination agent. The resulting products were purified (zwitterion content ≥ 0,95) and characterized with gel permeation chromatography, viscometry, static and dynamic light scattering and small-angle neutron scattering. In unpolar solvents as toluene, the polymeric zwitterions form clusters with molecular weights depending on concentration. In the dilute case, the clusters are relatively small and consist of approximately 8 zwitterions. The structure of these clusters is discussed by their scattering behaviour. Above a critical concentration being in the range of 0,05 g/cm3, an infinite aggregate is formed. Zwitterions in N,N-dimethylformamide behave differently: due to the attenuation of dipolar forces, no clusters are formed. In this case, the behaviour in dilute solution can be described by the formation of polymeric rings consisting of one polymer molecule, only.

https://doi.org/10.1002/macp.1991.021921217