Polypropylene/Layered Double Hydroxide Nanocomposites: Synergistic Effect of Designed Filler Modification and Compatibilizing Agent on the Morphology, Thermal, and Mechanical Properties

This work addresses the optimization of the morphology, thermal, and mechanical properties of polypropylene/layered double hydroxide (LDH) nanocomposites. For this, the nanofillers were modified by a calcination rehydration process using two surfactants, sodium dodecylsulfate (SDS) and sodium dodecylbenzenesulfonate, respectively. The nanofillers were characterized at each step of the modification process by thermal gravimetry, X-ray diffraction, and Infra red spectroscopy. Furthermore, the impact of anionic modifiers on the filler surface energy and on the interactions toward water was analyzed. Polypropylene (PP)/LDH nanocomposites were then prepared by a melt intercalation process and a high molar mass maleic anhydride functionalized polypropylene (PPgMA) was introduced as a compatibilizer. The dispersion of LDH in the PP matrix was characterized and the thermal and mechanical properties of the corresponding nanocomposites were determined and discussed as a function of the filler modification, of the nanocomposite morphology, and of the filler/matrix interfacial properties. The nanocomposites prepared from SDS modified LDH and PPgMA exhibited superior properties thanks to an optimized filler dispersion state and improved interfacial interactions. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 782-794