Synthesis And Characterization Of Lipophilic Aluminum Hydroxide Nanoparticles By In-situ Surface Modification

Aluminum Hydroxide (ATH), a type of a fire retardant and smoke suppressant, is a white crystalline powder with a chemical formula of Al(OH)₃, which is the most widely used for reinforced platics. However, hydrophilic surfaces of ATH nanoparticles are unfavorable for their dispersion in polymers. To solve this problem, the compatibility between inorganic particles and polymers must be enhanced. Surface modification is the most effective method, which will change ATH from hydrophile to hydrophobe.In this study, Using direct precipitation method, lipophilic aluminium hydroxides (ATH) nanoparticles were synthesized by in-situ surface modification method. The contents are showed as following:1. In theory, the thermodynamics and dynamics principles of the synthesis of ATH were analysed, and the factors of the ATH's synthesis were discussed.2. The properties of lipophilic aluminium hydroxides surface-modified with organic acid (isooctyl acid, cetylic acid and stearic acid), zirconiane in situ prepared by direct precipitation were characterized by TEM, IR, XPS, TG/DTA and XRD. The data show that the modified ATH (MATH) have plate-like or fibroid nanostructure, and were surrounded by a layer of organism through chemical bond, which make it disperse well in liquid paraffin equably. The existence of the organic layer prevented the particles from growing and agglomerate in the process of synthesis. The possible growing mechanism was proposed. In addition, the powders were also found to have an excellent antiwear property.