Synthesis and characterization of polydimethylsiloxane polyurea‐urethanes and related zwitterionomers

Abstract

A series of segmented polyurea urethane and polyurea block copolymers based on a hexane diisocyanate (HDI) modified aminopropyl terminated polydimethylsiloxane soft segment was synthesized. The hard segments consisted of 4,4′‐methylene diphenylene diisocyanate (MDI) which was chain extended with 1,4‐butanediol (BD), N‐methyldiethanolamine (MDEA), or ethylene diamine. Zwitterionomers were prepared by quaternizing the tertiary amine of the MDEA extended material with γ‐propane sultone. The effect of chemical structure on the extent of phase separation and physical properties was studied using a variety of techniques including thermal analysis, dynamic mechanical spectroscopy, tensile testing, and small‐angle x‐ray scattering. It was observed that the compatibility between the nonpolar polydimethylsiloxane soft segments and the polar urethane hard segments was improved by inserting HDI linkages into the polydimethylsiloxane soft segments. The aggregation of hard segments was enhanced by increasing hard‐segment content or by the introduction of ionic functionality. The tensile strength and modulus of these materials was higher than those of polyurethanes containing soft segments based on polydimethylsiloxane and its derivatives.

Synthesis, characterization and properties of chitosan modified with poly(ethylene glycol)–polydimethylsiloxane amphiphilic block copolymers

“…low toxicity, high oxygen permeability, good thermal and oxidative stability, are also suitable for use as biomaterials [11]. Medical devices made of polyurethane (PU) containing PDMS soft segment has been reported to exhibit better blood contact properties relative to commercially available PU [12][13][14]. Another advantage of adding PDMS into chitosan is to improve their mechanical properties.…”

Structure–property behavior of poly(dimethylsiloxane) based segmented polyurea copolymers modified with poly(propylene oxide)

“…These modifications include addition of silica fillers or incorporation of covalent cross-links, via peroxides, for example [2]. Over the past two decades, considerable attention has been directed at exploiting the properties of PDMS by utilizing it as a soft segment component in segmented copolymers, mainly polyurethanes and polyurethaneureas [4][5][6][7][8][9][10][11]. We recently reported the structure-property behavior of high MW segmented polyurethanes and polyurea counterparts based on PDMS as the soft segment (SS) component [12].…”

Enhanced Properties of Hyperbranched Polyurethane Elastomers Based on Polydimethylsiloxane/Polyether Mixed Soft Segments

“…Therefore, a number of methods have been confirmed to improve the phase mixing of these materials. The main approaches reported were to introduce polar functionality into PDMS backbone, or to use blended soft segments of PDMS and polyether-diol [13][14][15] . At present, some researchers have reported related copolymers, but they mainly concentrate on the studies of linear polyurethanes.…”