摘要：In this study, we examined three kinds of stabilizing additives to prepare stable MRF with good fluidity. We selected three stabilizing additives; a styrene isoprene block copolymer, a hydrophobic fumed silica, and an organogelator (CMOL SB03; PMDA-2C8/oleyl). We measured the rheological properties both for the dissolutions of the stabilizing additives in the base oil and MRFs prepared with the additives by using a rheometer; MCR302 (Anton Paar Corp.). From the experimental results, the viscosity of styrene isoprene block copolymer dissolution increased with concentration showing non-Newtonian properties. We selected a suitable concentration as 5wt% to satisfied good fluidity without forming gel. Since the viscosities of 7wt% fumed silica and 1wt% CMOL SB 03 dissolutions in the base oil consequently showed similar viscosity of the 5wt% copolymer, MRFs using such conditions were prepared. From the results of the stability test, the addition of the copolymer was effective to satisfy the stability of the MRF. We also found that the addition of such stabilizing additives were effective to increase the magnetic property of MRFs.
