Using inorganic filler to replace waste rubber powder is an important way to improve the performance of recycled rubber. However, the poor “inorganic-organic” interface is one of the bottlenecks limiting the application of inorganic fillers in the field of waste rubber regeneration. This paper innovatively proposed using stearic acid modified calcium carbonate powder (CCP), combined with supercritical fluid-assisted shear desulfurization technology to improve the interface bonding between waste rubber and calcite powder. The vulcanizable properties and mechanical properties of the reclaimed rubber prepared with unmodified CCP, KH570 modified CCP and stearic acid modified CCP were tested. The results showed that the reclaimed rubber prepared from CCPr modified by stearic acid exhibited good mechanical properties. The tensile strength of the regenerated rubber was 14.2%, 36.2%, and 11% higher than those of the regenerated rubber without CCP, unmodified CCP and KH570 modified CCP, respectively. Tear strength was higher by 7%, 16.2%, and 3.6%, respectively. The elongation at break was 13.4%, 26.8%, and 6.9% higher, respectively. This research is of great significance for improving the recycling properties of waste rubber and promoting the reuse of waste resources.

Keywords: stearic acid, calcium carbonate powder, recycled rubber.