Preparation And Application Of Highly Filled Silica/Natural Rubber Nanocomposite

Silica is an important rubber reinforcing material.However the surface of silica contains a large number of hydrophilic hydroxyl groups,so silica is not easily dispersed and need to be modified.Dry method,which is the traditional method to prepare silica/rubber nanocomposites,has the disadvantages of high energy consumption,low efficiency,uncontinuous production and dust pollution.In view of the above problems,we research and develop a unique,energy-saving and environmentally friendly mixing method:firstly we choose the silica modifier to prepare a stable silica slurry with nano-dispersion station.and then compound the silica slurry with the natural rubber latex,and finally use the spray drying method to obtain high-filled silica/natural rubber nanocomposites with excellent performance.The first part(Chapter 3)of this article uses different proportions of AEO9 and Si69 to modify silica slurry.AEO9 is better than Si69 in improving the stability of silica slurry.Under the action of colloid mill,AEO9 and Si69 can modify the surface of silica under the condition of water phase.What is more,the introduction of AEO9 reduces the emission of VOC during the modification of silica Compared with the siloxane structure coupling agent.The second part of this article(Chapter 4)uses a new type of silica modifier to prepare 100 phr silica/natural rubber nanocomposites under wet mixing conditions.The proportion of modifier/silica is 10%,When AEO9:Si69=1:3,the overall performance of the composite is more excellent than the composite by traditional in-situ modified blending method.The masterbatch is diluted with natural rubber to obtain a lower filler fraction of silica/natural rubber nanocomposite.The overall performance of the resulting composite is as good as that of the traditional in-situ modified blending method.The third part of this article(Chapter 5)uses a new type of silica modifier to prepare 60phr silica/natural rubber nanocomposites for different grades of silica under wet mixing conditions.The proportion of modifier/silica is 10%.We found that for the silica VN3,when the amount of AEO9 is lower than that of Si69,the comprehensive performance of the resulting composite material is better than the dry method.For silica 1165,when the amount of AEO9 is higher than that of Si69,the comprehensive performance of the resulting composite material is better than that of dry method.Considering that Si69 may fail in water,a experiment is conducted to study the effect of Si69 to modify the silica masterbatch in the dry method.As the amount of Si69 increases,the modulus and wear resistance of the composite material increase,but the heat generation increases.This is because in the process of preparing the masterbatch,AEO9 has been used to modify the silica slurry.In addition to the reaction sites on the surface of silica,at the same time,the protein and other substances in the latex will also cover the reaction sites on the surface of silica,so Si69 can not play a good role.