Study On The Reinforcing Function And Reinforcing Mechanism Of Nano Inorganic Fillers For Butadiene Rubber

Butadiene rubber (BR) is widely used in automobile tires, hardy products, etc., due to its good elasticity, excellent wear resistance and cold tolerance. However, it's tensile and tear strength are very low, as a result of which it must be filled with intensifier.The effects of particle size of TiO₂ and MgOon dynamic mechanical properties, vulcanization characteristics and physical properties of BR/ TiO₂ vulcanizates were studied in the former two parts. The results showed that the tensile strength of composites filled with nanoscale of TiO₂ was six times of pure BR, and its vulcanization time was significantly longer than the composite filled with micron grade filler. While the tensile strength of composites filled with nanoscale of MgO was nine times that of pure BR, and the vulcanization time was significantly shorter than the compostie filled with micron grade filler. Compared with the composites filled with micron grade of TiO₂ and MgO, the composites, which were filled with TiO₂ and MgO of 20nm and 50nm, have greatly higher value of tanδ, elasticity modulus and loss modulus. And also the latter has obvious Payne effect.In the third part, the vulcanization characteristics , physical properties and thermal stability of the BR based composites, which were respectively filled with blends of nano TiO₂/MgO and nano MgO/N220, were studied. The effects of the nano TiO₂ , MgO, N220 on the glass transition temperature, vulcanization reaction process, thermal stability and dynamic mechanical properties of BR were also studied. The results showed that the order of tensile and tear strengthof BR filled with blends of nano TiO₂/MgO are, BR/MgO>BR/TiO₂/MgO(15/25)>BR/TiO₂; The order of tensile and tear strengthof BR filled with blends of nano MgO/N220 respectivelyare, BR/MgO/N220(10/30)>BR/N220>BR/MgO,BR/N220>BR/MgO/N220(10/30)>BR/MgO; Nano TiO₂ can improve the thermal stability of BR; The glass transition temperature varied little when filled with different fillers. There is no exothermic peak during the vulcanization reaction process when filled with MgO, this indicates that there will be exist the endothermic reaction in the system; BR/MgO composites had the maximum value of elasticity modulus G'and the minmum value of loss modulus G″, and BR/N220 composites had the maximum value of G″, and BR/TiO₂ composites had the maximum value of tanδ.In the fourth part, we studied the effects of the varieties of modifier, different modification process and the different modifier content on the performance of the BR. The results showed that the vulcanization speed, crosslinking level and physical properties of vulcanizate with the modifier Si75 content being 3% of the filler are the best when we use in situ modification; Compared with unmodified nano-MgO, the modified nano-MgO significantly improved the physical properties and the dispersion of nano-MgO in rubber , and the drop magnitude of storage modulus became lower with strain increasing.