DYNAMIC STRAIN METHODS TO PROBE THE MORPHOLOGY OF UNCURED RUBBER COMPOUNDS

How the complex morphology of filled rubber compounds behaves under la rge dynamic strain was studied. Two methods are described: the progres sive damaging oi the compound morphology and the recovery behaviour of a purposely damaged morphology. Experimental data obtained with a var iety of compounds, based on SBR, NR, BR or EPDM, are used to demonstra te such techniques. The results are discussed with respect to a model morphology for filled compounds previously described: complex rubber-f iller entities with connective filaments. it is shown that the dynamic strain, and particularly the recovery behaviour does fit better the c apabilities oi a soft rubber-filler network than the breakdown of rile so-called secondary filler structure.