Chain mobility in solid polyelectrolyte complexes

Abstract

Abstract2H NMR is used to study the mobility of the alkylene chain in solid poly[(dimethyliminio)‐alkylene]s (α,ω‐ionenes) complexed with poly(styrenesulfonate). In 10, 10‐ionene the alkylene chain motion was probed on samples selectively deuterated at the 1‐, 2‐, and 4‐position as well as in the methyl part of the quaternary ammonium groups. 2H NMR spectra show that all positions in the polymethylene chains are involved in conformational jumps between trans and gauche states. The mobility of the methylene units adjacent to charged centres was found to be significantly reduced compared with that of units in the inner part of the chain. The charged quaternary ammonium groups themselves, however, do not take part in trans‐gauche isomerization. An increase in mobility resulting from increasing the length of the alkylene chains between the charge centres was observed in 3,3‐, 6,6‐ and 10,10‐ionene complexes labelled in the 2‐position. The differences in chain dynamics were also detected via EPR line shapes of small spin probe molecules incorporated into the complexes.