Project Details
Synthesis of covalently cross-linked amphiphilic co-networks with model character
Applicant
Dr. Frank Böhme
Subject Area
Preparatory and Physical Chemistry of Polymers
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 397384169
The subject of the project are covalently cross-linked amphiphilic co-networks of model character (model ACN), which are obtained by various hetero-complementary reactions of 4-arm stars of different philia. In this project, the question of the extent to which interactions of the reacting groups or the linkages formed during the cross-links influence the further course of the reaction and thus the microstructure of the networks will be investigated. In particular, it is suspected that deviations from the statistical course of the reaction occur in the presence of strong interactions, which may lead to deviations in the microstructure compared to other ACNs described in the literature. The linkage reactions are selected to cover a wide range of possible interactions. In the case of ester linkages, weak interactions should tend to occur, while strong interactions are expected for covalent-ionic linkages. A special case is represented by networks which are produced by a reversible Diels-Alder reaction. Such networks will be used to investigate the extent to which reaction-induced dynamic rearrangements affect the microstructure of ACNs. Another aspect of structure formation during synthesis are interactions of the hydrophobic and hydrophilic components, which can lead to phase separation and thus to pre-structuring of the networks. In this context, the use of star block copolymers with hydrophilic core and hydrophobic wings as starting materials for the synthesis of ACNs is envisaged. In this approach, collapse of the core can be caused by the use of selective solvents, which should have a significant impact on the network structure. The main goal is a better understanding of the structure-determining influences during network synthesis, as a prerequisite for the synthesis of model ACNs with a minimum of network defects. The evaluation of synthesis-related structural influences on the network formation will be based on investigations of chain connectivity and network mobility, network topology and permeability as well as network mechanics and rheology, which are covered by cooperation within the research group. Modelled structure-property correlations, which are provided by the theoretically oriented project partners, serve as evaluation criteria here.
DFG Programme
Research Units