STUDY OF PE-BASED COMPOSITES BY THE SPIN-PROBE METHOD

The spin-probe method was used to investigate the structure of composi tes prepared by blending of polyethylene with various contents of sili ca. When compared to original polyethylene, the temperature T50G was f ound to be lower at low filler content (4.7, 9.1%), but higher at high filler content (16.6, 25.9%). A relation between T50G and T(g) as der ived by A, T. Bullock [1], was used to calculate free volume of the co mposites in question at temperature T(g) (v(fg)). Average free volume was found to be much higher in samples with low silica content than in original PE, whereas at higher filler content the probe molecules are bound to the filler surface and Bullock's equation can not be applied .