An aqueous miscible organic (AMO) process for layered double hydroxides (LDHs) for the enhanced properties of polypropylene/LDH composites

Abstract

Enhancing the compatibility between inorganic fillers and polymers to obtain functionalized composites has always been a key issue. In this study, an aqueous miscible organic (AMO) method has been successfully adopted for conventional layered double hydroxide (LDH) fillers. Here, a series of D-LDH hybrid materials, intercalated by an organic antioxidant DBHP (D, 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), have been organically surface-modified using acetone as the solvent via the AMO method. To understand the effect of acetone exposure on the structure of the AMO D-LDH samples, XRD patterns, FT-IR spectra, TG-DTA curves and radical scavenging activity were thoroughly studied. The results indicate that the AMO method does not affect the layer structure of D-LDH but causes the co-intercalation of D⁻ with CO₃²⁻ anions, which can change the amount of DBHP in the interlayer and then influence the crystallinity, thermal stability and radical scavenging activity of D-LDH. Subsequently, the series of AMO D-LDH materials were used as anti-aging nanofillers for polypropylene (PP). The thermal stability, thermal-aging properties and migration resistance of the resulting PP/D-LDH (h) composites were investigated systematically. The results indicate that the AMO modification of D-LDH affects the content of DBHP and the interaction between the LDH fillers and PP chains, since an optimized modification time and content of DBHP are found to enhance the anti-aging performance of PP, as well as limits the migration of the DBHP molecules out of the PP films.