Research On Preparation And Application Of High Performance Organolayer Silicates

Layered silicate is a kind of clay mineral which are easy to get and have low costs.It has a unique lamella structure,high aspect ratio and large specific surface area.Therefore,its use as a polymer reinforcing filler has attracted widespread attention.Organically modifying it to transform it from the original inorganic phase to the organic phase is an effective and reasonable way to enhance the compatibility with the polymer.In this paper,a bio-based amphoteric surfactant-cocamidopropyl betaine(CAPB)organically modified sodium-based montmorillonite(Na-MMT)was used to explain the mechanism of organic modification and clarify the organic.The key process parameters of the modification reveal the corresponding relationship between the organic modification and the dynamic and static properties of the clay/bromobutyl rubber(BIIR)composite materials,especially the airtightness.The main work is as follows:(1)The organically modified clay is prepared by adjusting the mass ratio of CAPB and Na-MMT.The conditions of organic modification are:the solid content of the clay suspension is 2%,the reaction temperature is 60?,and the reaction time is 6 h.The interlayer spacing of the clay flakes increases with the increase of the amount of CAPB.Next,the above-mentioned organically modified clay was compounded with BIIR,and it was found that the clay was well dispersed in the rubber matrix,and the air-tight performance was significantly improved,indicating that CAPB is an excellent modifier for inorganic clay.The problem is that the yield of organically modified clay is low,which is not conducive to industrial application.To solve the problem of low yield of organically modified clay as above,increase the concentration of the clay suspension.The ratio of CAPB to clay mass is the same as in Chapter 3.It is found that.increasing the solid content of clay does not affect the organic modification effect,and improves the organic modification and the yield of clay.Then a small amount of organically modified clay was used to compound with BIIR,and it was found that organically modified clay can already improve the airtightness of the BIIR matrix.(2)The effect of the time of organic modification on the properties of clay and its composite materials was explored.It is found that the time variable has no effect on the microscopic properties of the organoclay,and the reaction efficiency can be improved.Nanocomposites were prepared by compounding organoclays with different time variables and BIIR to investigate the dynamic and static properties,especially the air-tightness performance.It was found that when the reaction time is 3 h,the air-tightness improvement requirements can be met and the performance is the best,while improving the reaction efficiency and less impact on other performance.The optimal reaction time of organoclay is 3 h.(3)The influence of the pH value of organic modification on the properties of clay and its composite materials was explored.From the relevant microscopic characterization,it can be concluded that the amount of acid will affect the charge density of the clay flakes and the hydroxyl groups contained,so the amount of acid should not be large.The dynamic and static properties of nanocomposites prepared by using HCl solution to adjust different pH values of organoclay and BIIR were investigated,especially the air-tight performance,and it was found that the air-tight performance was the best when it was weakly acidic.