Ionic Interactions in Blends of Polyamidines and Proton Donor Terminated Poly(alkylene ether)s

Abstract

4-(Iminomethyl)phenol and 4-(iminomethyl)benzoic acid terminated aliphatic polyethers were obtained by conversion of Jeffamines with respective aromatic aldehydes. Mixtures of these polymers with polyamidines showed improved compatibility or even complete miscibility because of ionic complexes formed between the end groups of the modified polyethers and the basic amidine groups. Depending on composition and molecular weight of the components, blends with two or one glass transitions were obtained. In the case of 4-(iminomethyl)phenol terminated polyethers, deprotonation of the end groups resulted in a distinct change of the UV/vis absorption spectrum. This spectral alteration is discussed with respect to quantification of interactions in polymer blends.

Synthesis and Ionic Interactions of a Proton Donor Terminated Polyalkylene Ether

“…In a recent example,16 we showed that a polymer bound 4‐(iminomethyl)phenol moiety (Schiff's base) also acts as an effective optical probe for interactions in polymer blends. However, the effects observed with this chromophore were limited to the UV range of the spectrum.…”

“…The reason for this effect was the formation of ionic complexes between the polymer and the chromophore. In another example we showed that a 4‐(iminomethyl)phenol moiety (Schiff's base), introduced at the chain ends of an aliphatic polyether (Jeffamine), acted as a probe for specific acid–base interactions in polymer mixtures 16. Owing to the deprotonation of the terminal group, a bathochromic shift of the absorption band was observed from 270 to 330 nm.…”