Synthesis and Thermal Decomposition Behavior of Zircoaluminate Coupling Agents

Zircoaluminate coupling agents can be used as surface modifiers or adhesion additives in many applications, such as plastics, rubbers, coatings, and pigments. In this paper, a range of zircoaluminates with different functional groups were synthesized, by using polyaluminum chloride (PAC), zirconium oxychloride, 1,2-propanediol, and others. The products were characterized by FTIR, MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry), and TGA. FTIR spectra indicated that the multiple bands at 1636-1567 cm(-1) are the characteristics of zircoaluminates. The number-average molecular weight and weight-average molecular weight of carboxyl functional zircoaluminate (sample ZA-C6) are 2125 and 2295 g/mol, respectively, as determined by MALDI-TOF MS. The molar ratio of reactants and selected organofunctional ligands can affect not only the properties but also the thermal stabilities of final products. TGA results showed that the decomposition of zircoaluminates includes four distinct stages and dodecyl functional zircoaluminate (sample ZA-F) has the highest decomposition temperature of 374 degrees C.