SMALL-ANGLE X-RAY AND LIGHT-SCATTERING FROM RANDOMLY BRANCHED POLYCYANURATES

A study by small-angle X-ray and light scattering of dilute solutions of randomly branched polycyanurates is presented. By combining the sca ttering intensities of the two methods on an absolute scale, the range from 4 x 10(-3) to 7 nm(-1) of the wave vector q was available for da ta analysis. The scattering curves of polymers with different weight-a verage molecular weights could be well fitted using an expression for the form factor derived from the theory of mass fractals. The analysis of the data obtained by combination of the two scattering experiments gave reliable results for the molecular weight, radius of gyration, a nd fractal dimension of the polycyanurate samples that match the resul ts of viscometry and size-exclusion chromatography of the same polymer ic system.