LI-7 STATIC AND MAS NMR-STUDIES ON BLENDS OF POLYAMIDE-6 AND LITHIUM SULFONATED POLYSTYRENE IONOMERS

Li-7 nuclear magnetic resonance (n.m.r.) spectra obtained in static mo de were used to characterize blends of polyamide-6 (PA6) and lithium s ulfonated polystyrene ionomers (LiSPS) with 5.4 and 9.7 mol% sulfonate groups, for the blends with the higher degree of sulfonation a linear relation was found between full n.m.r. line width at half-maximum (FW HM) and the glass transition temperature (T-g, as determined by differ ential scanning calorimetry, d.s.c.). Magic angle spinning (MAS) spect ra were also recorded and it was shown, in particular, that the line w idth of the central transition provides information on polymer miscibi lity on a scale smaller than 2 nm. Based on simulations of the Li-7 sp ectral data, it is suggested that three lithium species are present, w hose concentration is determined by the sulfonated polystyrene/PA6 rat io in the blend; the miscibility of the blend is shown to be mainly co rrelated with one of the species. (C) 1998 Elsevier Science Ltd. All r ights reserved.