Advanced Torsional Dynamic Methods to Study the Morphology of Uncured Filled Rubber Compounds

摘要

Uncured compounds of SBRl500 with various levels of silica were studied using a torsional dynamic tester (rubber process analyzer; RPA). Silica-filled com- pounds were prepared with the appropriate amounts (8.2%) of silane, i.e., bis(3-tri;. ethoxysilylpropyl)tetrasulfane (TESPT). A carbon black-filled compound was also stud- ied for comparison. Strain sweep tests at constant frequency show that filled rubber materials exhibit either no or limited linear viscoelastic domain. Frequency sweep tests were performed either at the lowest strain amplitude or within the linear range at several temperatures; results ,vere treated through time-temperatUre superposition in order to yield G' and G" master curves at the reference temperature of lOO°C. Special test procedures were applied that are known to give interesting information about the morphology 9f complex polymer systems: the morphology damaging test (MDT) and the damaged morphology recovery test (DMRT). Results obtained are discussed with re- spect to the likely morphology of carbon black and silica-filled rubber compounds.