In the polyamides 4.12, 10.6, 8.8 and 6.10 three fractions are present. The WAXD crystallinity is comparable to that of DSC and amounts to 40% in all samples. The rigid fraction obtained by solid state NMR is, however, close to 60%, pointing at 20% rigid amorphous material. A combination of the NMR, WAXD and SAXS results reveals that the latter fraction is situated inside the crystalline phase and not at the crystalline – ‘mobile amorphous’ interface. Accordingly, one third of the crystalline layers with a thickness between 50 and 56 Å is not truly crystalline. From the width of the WAXD 100 reflections it can be deduced that crystalline grains exist with lateral dimensions of approximately 100 Å. Hence a picture emerges of alternating solid and liquid-like layers with the former consisting of crystalline grains separated by rigid amorphous matter.
|Title of host publication||Scattering methods and the properties of polymer materials|
|Place of Publication||Berlin|
|Number of pages||11|
|Publication status||Published - 2005|
|Name||Progress in colloid and polymer science|