ZnO Nanoparticles Bonded to SiO2 Filler as a Curing Accelerator in Cold Vulcanizing Adhesives

Abstract

The aim of this study is to investigate the interaction of ZnO/SiO2 particles between the chloroprene rubber and its effect on the cure characteristics and mechanical properties of the cold vulcanizing adhesives. Curing efficiency and mechanical properties of ZnO/SiO2 filled adhesives were compared with SiO2 filled adhesives. ZnO nanoparticles were bounded to SiO2 spherical nanoparticles by hydrolysis and condensation process. The morphology and elemental content of ZnO/SiO2 particles were investigated by scanning electron microscopy and energy dispersive spectroscopy. The ZnO/SiO2 particles were then blended with chloroprene rubber as accelerator during the vulcanization process. Cure characteristics, which are scorch time (ts2), cure time (tc90), maximum torque (MH) and minimum torque (ML) of the rubber compounds were determined at 190 C with a moving die rheometer. The fabric conveyor belt was used for measuring adhesive strength of the adhesives. The fabric conveyor belt was used for measuring adhesive strength of the adhesives. Application of the cold vulcanizing adhesives to the fabric conveyor belt was carried out at three different times (4, 8, and 24 h), 25 C temperature and 0.3 kg/cm2 pressure. The results showed that ZnO/SiO2 particles provided a higher adhesive strength than silica in the 4, 8, and 24 h of adhesion. ZnO/SiO2 filled rubber blends gained superior vulcanization characteristics by the increasing cure rate index with the reducing cure time and scorch time. It has been concluded that ZnO/SiO2 particles can be used as a new curing accelerator and simultaneously reinforcing filler.