“…To date, the utilized unsaturated elastomers have been natural rubber [39][40][41] and synthetic rubber, i.e. styrene butadiene rubber [42], chloroprene rubber (CIIR) [43], Bromo butyl rubber (BIIR) [44], isobutylene-isoprene [39], cispolyisoprene [45], cis-polybutadiene [27,[46][47][48][49][50], acrylonitrile rubber [51][52][53][54], and ethylene-propylene rubber [53,54]. The magnetizable particles used for MREs are commonly provided by well-known chemical companies such as BASF (carbonyl iron, spherical shape, 1-20 microns) [52,[55][56][57], ISP (carbonyl iron, spherical) [40,[58][59][60], Hoganas (iron powder, irregular shape above 20 micron) [61,62], and Sigma-Aldrich (carbonyl iron/iron pentacarbonyl) [63][64][65].…”