Synthesis and Morphology of Segmented Poly(tetramethylene oxide)-Based Polyurethanes Containing Phosphonium Salts

Abstract

A fundamental investigation of the influence of novel phosphonium bromide salts within the polymer main chain (23.75 mol %) of polyurethanes was conducted to elucidate the effect of ionic associations on hard segment hydrogen bonding. A novel poly(tetramethylene oxide) (PTMO)-based polyurethane containing a phosphonium diol chain extender was prepared using a conventional prepolymer method. In addition, a polyurethane containing a 1,4-butanediol chain extender was synthesized for comparison with the thermomechanical and morphological properties of the phosphonium ion-containing analog. Moreover, the unprecedented comparison of morphological development in the presence of cationic sites is described herein. Differential scanning calorimetry (DSC) revealed that phosphonium polyurethane was more crystalline compared to the noncharged analog, and it was presumed that enhanced hydrogen bonding in the noncharged polyurethane restricted polymer mobility and reduced PTMO crystallinity. Moreover, FT-IR spectroscopy demonstrated that hydrogen-bonding interactions were significantly reduced in the presence of phosphonium cations. These results correlated well with tensile properties, i.e., the noncharged polyurethane offered superior tensile strength compared to phosphonium polyurethane. X-ray scattering indicated that both polyurethanes were amorphous at room temperature and exhibited hard segment microphase separation. Upon stretching, the interparticle scattering between the microphase-separated domains aligned preferentially along the stretching direction. Scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDS) in the STEM indicated that the charged polyurethane exhibited ionic aggregates that were rich in P and Br.

Polyurethanes Containing an Imidazolium Diol‐Based Ionic‐Liquid Chain Extender for Incorporation of Ionic‐Liquid Electrolytes

“…This suggested that HMDI‐BD‐2KPTMO possessed more hydrogen bonding than HMDI‐IMI‐2KPTMO. This observation is consistent with the literature: our previous study demonstrated that polyurethanes with phosphonium cations in the hard segments showed significantly reduced hydrogen bonding 29. It is also interesting to note that the hydrogen bonding in these polyurethanes was related to their hard segment crystallization.…”

Synthesis, Properties, and Applications of Ion‐Containing Polyurethane Segmented Copolymers

“…The effect of charge placement and content on polymer properties is discussed in detail in later sections of this review. The inherent versatility in segmented polyurethane synthesis gives rise to a seemingly limitless array of possible architectures with the required functionalities (diol, diisocyanate, polyol), including anionic, cationic, and even zwitterionic monomers . For example, Scheme shows the synthetic route for a zwitterionic sulfobetaine diol …”

Characterization and antipathogenic evaluation of a novel quaternary phosphonium tripolyacrylamide and elucidation of the inactivation mechanisms

“…Furthermore, many researchers have revealed the high flame retardancy of phosphorus‐containing compounds . All the features of QPS generate polymeric QPS with many new or potential applications . Ornelas‐Megiatto et al developed a novel water‐soluble polymeric QPS and compared with its ammonium analog in terms of siRNA delivery.…”