Rheological properties of short melamine fibre filled EPDM rubber

摘要

The effects of concentration of short melamine fibres and of a dry bonding system consisting of resorcinol, silica, and hexamethylene tetramine on the rheological properties of EPDM rubber compounds have been investigated using a capillary rheometer. All the compounds behaved as pseudoplastic materials and followed the power law model. It was found that the apparent viscosity of the compounds shows a maximum at 40 pphr fibre loading. It was also observed that all three components of the dry bonding system must be present together to decrease the die swell of the extrudates. Morphological analysis of the extrudates using scanning electron microscopy revealed that melt fracture, which is observed at higher shear rates for the compositions containing no fibres, is absent in the compositions containing fibres. An alignment of the fibres in the shear field was also observed in the micrographs of cross-sections through the extrudates.