Electrical and mechanical properties of ethylene propylene diene monomer-chloroprene rubber blend loaded with white and black fillers

The permittivity epsilon' and dielectric loss epsilon " for different ratios of an ethylene propylene diene monomer (EPDM)-chloroprene rubber (CR) blend ranging from 0 to 100 phr were measured over a frequency range from 400 Hz to 60 kHz. The measurements were carried out at room temperature (25 degrees C). The values of epsilon' and epsilon " were found to decrease with increasing EPDM content in the EPDM-CR blend. The sample which possesses the best mechanical and electrical properties was a 50 EPDM-50 CR blend. This sample was chosen to be loaded with 40 phr of some white fillers, namely, calcium carbonate, silica, silitan z, and talc. From the electrical and mechanical investigations, it was found that the use of silica and calcium carbonate in these blends could improve these properties. The electrical and mechanical properties were also studied for the investigated blends loaded with both silica and calcium carbonate with different contents (10-40 phr). It was found that 20 phr is the most promising concentration which can possess better properties. The same trend was obtained by the addition of 20 phr SRF black in addition to the white fillers to the above blends. On the other hand, from the compatibility study between both investigated rubber, it is found that both types are incompatible, in which some improvement may occur by the addition of PVC. (C) 1998 John Wiley & Sons, Inc.