Novel Functionally Grafted Pseudo-Semi-interpenetrating Networks Constructed by Reactive Linear−Dendritic Copolymers1

Abstract

This paper describes the synthesis of amphiphilic pseudo-semi-interpenetrating polymer networks (pseudo-semi-IPNs) containing linear poly(styrene) and poly(ethylene glycol) (PEG) cross-linked through monodendritic fragments. A unique feature of the synthetic strategy is the permanent attachment of the linear segment to the PEG network by a transesterification reaction between the hydroxyl groups at both ends of the PEG and peripheral ethyl ester moieties in the monodendron portion of a linear poly(styrene)-dendritic poly(benzyl ether) AB block copolymer. The proceeding of the reaction is monitored by (1)H NMR and size exclusion chromatography (SEC). The formation of an interlock structure between the linear block and the network matrix in the pseudo-semi-IPN is evidenced by the results from spectroscopic analyses and differential scanning calorimetry measurements. The accessibility of functional centers in the grafted semi-IPN is confirmed by model reactions with fluorescent markers, fluorescence spectroscopy, and NMR techniques and shows the potential of these novel materials as sequestering reagents for resin capture-release applications in parallel synthesis, combinatorial chemistry, and advanced drug design.