Fabrication and Characterization of Natural Rubber-Based Magnetorheological Elastomers at Large Strain for Base Isolators

Table 5

MRE samples with various mixing ratio of carbon black and naphthenic oil (iron ratio: 35%).

Sample	C20N20	C40N20	C20N40	C40N40	C60N40
Amount of carbon black (phr)	20	40	20	40	60
Amount of oil (phr)	20	20	40	40	40
Mass ratio; (%)
Rubber	13.5	12.4	11.7	10.9	10.2
Iron	79.6	78.8	79.9	79.1	78.5
Carbon black	2.7	5.0	2.3	4.4	6.1
Oil	2.7	2.5	4.7	4.4	4.1
etc.	1.5	1.3	1.4	1.2	1.1
Volume ratio (%)
Rubber	48.3	44.9	42.0	39.4	37.1
Iron	35.0	35.0	35.0	35.0	35.0
Carbon black	4.9	9.1	4.2	8.0	11.3
Oil	9.7	9.0	16.8	15.8	14.9
etc.	2.1	2.0	2.0	1.8	1.7