SEGMENTED BLOCK COPOLYETHERAMIDES BASED ON NYLON-6 AND POLYOXYPROPYLENE .3. SAXS ANALYSIS

Morphologic characteristics of segmented block copolyetheramides based on nylon 6 and polyoxypropylene (POP) were investigated as a function of the compositions and block lengths of the hard and soft segments u sing small angle X-ray scattering (SAXS). Three POPs with different mo lecular weights were used as a soft segment. One-dimensional correlati on functions were obtained from the desmeared intensity SAXS curves us ing the method developed by Vonk and Kortleve. The interdomain spacing s were determined from the correlation distance at the peak position o f the correlation function. From the dependence of the correlation dis tance on soft segment content, we deduced that an increase in the hard -segment length may lead to crystal formation by a chain-folding mecha nism. The thickness of phase boundary was determined from the smeared intensity data using the method of Koberstein. A decrease in the phase boundary thickness with increasing soft-segment content suggests that an increase in the chain mobility by soft segment facilitates the reg ular arrangement of the hard segment, resulting in the formation of th e hard domain with a narrow interfacial region. (C) 1997 John Wiley & Sons, Inc.