Effects of different vulcanization systems on electromagnetic shielding effectiveness of Eucommia ulmoides gum composites

The effects of common vulcanization （CV) system, semi-effective vulcanization （SEV) system, effective vulcanization （EV) system, and dicumene peroxide （DCP) vulcanization system on the mechanical properties and electromagnetic shielding effectiveness of Eucommia ulmoides gum （EUG) composites were studied. The results showed that the difference in vulcanization rates of CV system, SEV system and EV system was not significant, and the DCP vulcanization system had the lowest vulcanization rate and crosslinking degree, and exhibited the highest crystallinity degree. The elongation at break of EUG composites of the sulfur vulcanization systems were all higher than that of EUG composite of the peroxide vulcanization system, but the tensile strength was lower, and when DCP was used as the vulcanization agent, the tensile strength of EUG composite could increase by up to 10.6% compared with that of EUG composites of the sulfur vulcanization systems. EUG composites of sulfur vulcanization system exhibited good conductivity and the higher crosslinking density, which was conducive to the formation of conductive network, and the electromagnetic shielding effectiveness of EUG compo-sites of the EV system was 22% higher than that of EUG composites of the unvulcanized system.