Chemical Modification of Montmorillonite

The compatibilizer as such may be compatible with the clay surfaces and hence easily intercalates into the interlayer spacing of the clay platelets and separates the clay platelets, and with bulk polymer it leads to the formation of well-dispersed nanocomposites. The compatibilizer widely used for polypropylene (PP) is maleic anhydride grafted PP (PP-g-MA) [15-16], Other compatibilizers used are diethyl maleate (DEM-g-PP) and polyolefin elastomer grafted maleic anhydride (POE-g-MA), 

The clay platelets can be modified by different methods like adsorption, ion exchange, grafting of organic compounds, reaction with adds, polymerization, and physical treatments, such as lyophilization, ultrasoimd, and plasma. 

Cation exchange with organo-onium ions is a common method, which helps to disperse clay platelets in organic solvents and makes them compatible with hydrophobic polymers. 

The montmorillonite clay adsorbs certain cations and they remain as exchangeable cations. The most common exchangeable cations are Na+, Ca, Mg +, H+, K+ and NH. When clay is placed in a solution of a given electrolyte, an exchange occurs between the ions of the clay (X ) and those of the electrolyte (Y+). 

This reaction is balanced, and the extent to which the reaction proceeds from the left to the right depends on the nature of the cations X and Y+, and their relative concentrations. 

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