Poly(propylene glycol)‐based ammonium ionenes as segmented ion‐containing block copolymers

Abstract

AbstractThe synthesis and characterization of series of segmented poly(propylene glycol) (PPG)‐based ammonium ionenes is described. Bromine end‐capped oligomers were successfully synthesized using the reaction of 6‐bromohexanoyl chloride with 1000, 2000, and 4000 g/mol PPGs. 1H NMR spectroscopy, titration studies, and matrix‐assisted laser desorption ionization‐time of flight (MALDI‐TOF) mass spectrometry revealed the difunctionality of the oligomers. First, a series of PPG‐based ammonium ionenes was synthesized from bromine end‐capped PPG oligomers and N,N,N′,N′‐tetramethyl‐1,6‐hexanediamine. For this series, a single glass transition temperature (Tg) of approximately −66 °C was observed through differential scanning calorimetry (DSC); dynamic mechanical analysis (DMA) showed the onset of flow ranged from 20 to 80 °C. In addition, a series of PPG‐based ammonium ionenes containing 1,12‐dibromododecane was synthesized to increase the aliphatic hard segment (HS) content and enhance the mechanical properties of the resulting materials. For these, two Tg's were observed using DMA; DMA also showed the onset of flow of ionenes containing higher HS content (33 wt %) occurred in the range of 100–140 °C. Tensile analysis for these ionenes demonstrated an average tensile strength at break ranging from 0.2 to 2.4 MPa. Small angle X‐ray scattering (SAXS) profiles for these ionenes showed that Bragg distances increase linearly with the molecular weight of PPG soft segment. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4159–4167, 2010