Preparation And Performance Research Of Low Heat Build-up Natural Rubber Composites

At present,the use of silica-reinforced natural rubber to prepare green tires has become the mainstream of rubber research,but there is little research on the heat-generating properties of silica/natural rubber composites.Low heat build-up rubber is very important for load-bearing tires,which can not only reduce the tire heating problem during use,avoid danger,but also improve the service life.At the same time,in order to make up for the lack of mechanical properties of silica/natural rubber composite materials,graphene oxide and silica with excellent mechanical properties were selected to reinforce natural rubber.The main contents are as follows:?1?Low heat build-up silica/natural rubber composites were prepared by using silica particles filled with dodecanol and silane coupling agent KH-592 to modify natural rubber,and the filler-filler and filler-rubber matrix were systematically studied The influence of the strength of the interaction on the compression heat generation performance of rubber composites.The two modifiers have different effects.Dodecanol is grafted to the surface of silica,which mainly plays a role of shielding hydroxyl groups,thereby weakening the agglomeration of silica particles and improving their dispersion.Because the silane coupling agent KH-592 contains a sulfhydryl group,it can form a covalent connection between the silica and the natural rubber molecular chain,thereby enhancing the interaction between the filler and the rubber matrix.The results show that the D6K4-C group of vulcanized rubber has the weakest Payne effect and the most content of binding rubber,and its heat generation performance is the lowest,reaching11.3?.This shows that the weak filler interaction and the strong filler-matrix interaction will reduce the internal friction,the hysteresis loss and the heat generation of the rubber composite.?2?In order to solve the problem of weak mechanical properties of silica/natural rubber,graphene oxide and silica are used for electrostatic assembly and filling of natural rubber.From the gradient experiment of graphene oxide content,no matter what combination of silica and graphene is,when the amount of graphene oxide is 1phr,the performance of the obtained rubber composite is the highest in the same group.When the amount of graphene oxide is 1phr,by comparing the combination of three kinds of silica and graphene oxide,it is found that SiO₂-M2@GO/NR vulcanizate has the highest mechanical properties and the lowest heat generation.Next is SiO₂-M1@GO/NR vulcanizate,and finally SiO₂-GO/NR vulcanizate.This shows that silica particles modified by KH-550 and KH-592 in SiO₂-M2@GO/NR not only complete electrostatic assembly with graphene oxide under the action of KH-550,and improve the dispersibility of graphene oxide,Moreover,under the action of KH-592,the SiO₂@GO composite particles and the natural rubber molecular chain are thought to be covalently connected,the interaction between the filler and the matrix is enhanced,and the comprehensive performance of the rubber composite material is improved.In SiO₂-M1@GO/NR,the silica is not modified by KH-592,and the interaction between the filler and the matrix is not enhanced,so the performance improvement is weak.