Natural zeolite particles of 40, 80 and I00 phr were incorporated into natural rubber （NR） using a two-roll mill. The surface treatment of zeolite particles was expected to improve their cure characteristics and the...Natural zeolite particles of 40, 80 and I00 phr were incorporated into natural rubber （NR） using a two-roll mill. The surface treatment of zeolite particles was expected to improve their cure characteristics and their tensile properties. Two types of silane coupling agents, i.e., bis-[3-（triethoxysilyl）-propyl]-tetrasulfide （Coupling 89） and 3-Octanoylthio-l-propyltriethoxysilane （NXT） at various loadings of 2, 4 and 8 percent by weight （%wt） were selected. The viscosity and cure time of the rubber compound increased, while the scorch time decreased after the treatment of zeolite by both coupling agents. The viscosity of the rubber compound predominantly increased when increasing Coupling 89, however, NXT loadings showed no significant effect on the cure characteristics Moreover, the amount and type of coupling agent influenced the tensile properties of the vulcanizates, as a result of the increase in tensile strength, and tensile modulus with increasing both coupling agents loading. The tensile properties of the vulcanizates increased at low Coupling 89 concentrations （2-4%wt）, but decreased at high Coupling 89 loading （8%wt）. Since NXT has a less bulky structure and lower viscosity compared with Coupling 89, it thus reacts with the silanol groups on the zeolite surface more readily, resulting in the decrease in filler-filler interaction, leading to better tensile properties.展开更多
文摘Natural zeolite particles of 40, 80 and I00 phr were incorporated into natural rubber （NR） using a two-roll mill. The surface treatment of zeolite particles was expected to improve their cure characteristics and their tensile properties. Two types of silane coupling agents, i.e., bis-[3-（triethoxysilyl）-propyl]-tetrasulfide （Coupling 89） and 3-Octanoylthio-l-propyltriethoxysilane （NXT） at various loadings of 2, 4 and 8 percent by weight （%wt） were selected. The viscosity and cure time of the rubber compound increased, while the scorch time decreased after the treatment of zeolite by both coupling agents. The viscosity of the rubber compound predominantly increased when increasing Coupling 89, however, NXT loadings showed no significant effect on the cure characteristics Moreover, the amount and type of coupling agent influenced the tensile properties of the vulcanizates, as a result of the increase in tensile strength, and tensile modulus with increasing both coupling agents loading. The tensile properties of the vulcanizates increased at low Coupling 89 concentrations （2-4%wt）, but decreased at high Coupling 89 loading （8%wt）. Since NXT has a less bulky structure and lower viscosity compared with Coupling 89, it thus reacts with the silanol groups on the zeolite surface more readily, resulting in the decrease in filler-filler interaction, leading to better tensile properties.
