Characterization Of Vulcanization Accelerator

Promoting efficiency of rubber vulcanization is an important standard to measure the quality of accelerator. According to reports, the characterization of accelerators at home and abroad is mainly carried out from the two aspects of vulcanization promotion characteristics and physical and mechanical properties of vulcanized rubber. The main characteristics of vulcanization promotion are the vulcanization rate, Mooney coke time, positive vulcanization time, positive vulcanization temperature, vulcanization flatness and anti-vulcanization returnability in overvulcanization stage. The physical and mechanical properties of vulcanized rubber are mainly investigated in terms of hardness, elasticity, tensile properties, friction properties and thermal aging properties. However, in recent years, a lot of research has been done on the influence of accelerators on the dynamic viscoelastic properties of vulcanizates. In fact, the effectiveness of the accelerator depends on the physical and mechanical properties of the vulcanizate it imparts, and the nature of the cross-linked bonds in the vulcanizate (type and density) plays a decisive role in its application and working characteristics. The strength and dynamic mechanical strength of vulcanized rubber not only depend on the properties of the polymer chain itself, but also directly related to the number of network support chains in the total interconnection network (referring to the connection chain between two connecting points). The crosslinking density determines the number of supporting chains in the network. It has been reported [14] that the hardness and constant elongation stress of vulcanized rubber increase with the increase of crosslinking density, and the tear strength, fatigue life, toughness and tensile strength begin to increase with the increase of crosslinking density, and then decrease with the increase of crosslinking density after reaching a certain maximum value. The hysteresis and permanent deformation characteristics decrease with the increase of crosslinking density.