COMBINED IN-SITU SMALL AND WIDE-ANGLE SYNCHROTRON X-RAY-SCATTERING (SAXS-WAXS) APPLIED TO A SOLID-STATE POLYMERIZATION REACTION

The solid-state elimination reaction in sodium chloroacetate was studi ed with in-situ combined small- and wide-angle X-ray scattering (SAXS- WAXS). This reaction leads to sodium chloride cubes (d approximate to 1 mu m) finely dispersed in a matrix of partially crystalline polyglyc olide, poly(hydroxyacetic acid). The wide-angle data confirm a single- step reaction without detectable intermediate. The formation of the su perstructure of polyglycolide (detectable by SAXS) is delayed compared to the formation of crystalline domains (detectable by WAXS). This is indicated by the intensity of the long period diffraction peak at s = 0.104 nm(-1). (C) 1998 Elsevier Science Ltd. All rights reserved.