Continuous fractionation of poly[(dimethylimino)decamethylene bromide] and molecular weight dependence of the glass transition

30 g of the ionene poly[(dimethylimino)decamethylene bromide] were fractionated by a continuous counter-current extraction method (CPF) using ethylene glycol monoethyl ether as the solvent and diisopropyl ether as the non-solvent component. The efficiency of the separation was checked by viscometry and gel-permeation chromatography (GPC) measurements. Eight fractions of different molar mass were prepared for differential scanning calorimetry (DSC) experiments. With bromide as counter-ion, the glass transition temperature of the ionene increases from ca. 60 to 85°C as the intrinsic viscosity of this material (in 0,4 M aqueous solutions of KBr at 25°C) rises from ca. 14 to 22 mL/g. When bromi…

Influence of chain length on the molecular dynamics of an aliphatic ionene

An aliphatic random copolymer ionene (a cationic polyelectrolyte with N + in the repeat unit), was fractionated with the continuous polymer fractionation and investigated for its molecular weight dependent properties. The fractions were analyzed with GPC and capillary viscometry for their molecular weight. Glass transition temperatures were determined with DSC and a strong molecular weight dependence was observed, but no influence in the ionic conductivity was observed. The temperature dependency of ionic conductivity in ionenes is described.

About 340 g of a cycloaliphatic ionene (see formula given in the introduction) were fractionated by a continuous countercurrent extraction method (CPF). The efficiency of the separation was checked by viscometry and gel permeation chromatography (GPC). Ten different fractions with number average molecular masses between 16 000 and 29 000 D were obtained and their glass transition temperatures T g determined by differential scanning calorimetry (DSC) for their bromide and tetrafluoroborate salts. No molecular weight dependence of T g was found, in contrast to recently reported results with aliphatic ionenes, where - in case of the bromide - T g increases with rising molecular weight.

Complexes of an anionic poly(p-phenylene) polyelectrolyte and dioctadecylammonium bromide at the air–water interface

Abstract By spreading dioctadecyldimethylammonium bromide on a subphase containing rigid rod-like anionic poly( p -phenylene) sulfonate, a complex monolayer is formed in situ at the air–water interface. Complexation results in an increase of the area per amphiphile molecule compared to the amphiphile on pure water. The change in structural order upon complexation and subsequent compression of the monolayer can be demonstrated employing UV/Vis spectroscopy: A red-shift of the polymer absorption band upon compression and a subsequent partial reversion of this shift after monolayer collapse can be observed. The peak shift is discussed to be a result of the electronic interaction of the π -syst…

Integrated Linear and Nonlinear Optics with Novel Macromolecular Systems

ABSTRACTThis paper deals with the application of some recently developed evanescent waveoptical techniques for the characterization of novel macromolecular host-guest systems. In particular, surface plasmon- and guided optical wave-spectroscopies and -microscopies are used to determine the linear and nonlinear optical properties of these materials in thin film form.