Intercalative redox polymerization and characterization of poly(4‐vinylpyridine)–vermiculite nanocomposite

Abstract

ABSTRACT:A new nanocomposite material consisting of poly(4-vinylpyridine) (PVP) and vermiculite is synthesized by the intercalative redox polymerization of VP in the gallery of copper(II) ion-exchanged vermiculite. The formation of a single filament of the polymer in the gallery is confirmed by the increase in gallery spacing of 4.7 Å as indicated by X-ray diffraction (XRD) analysis. Electron spin resonance studies confirm the presence of Cu(II) upon ion exchange and its absence following redox polymerization. The amount of polymer present in the gallery is found to be ϳ18 -19 mass % by thermogravimetric analysis. Confining the polymer to the gallery spacing in vermiculite results in enhanced thermal stability that is evident from the increase in the initial decomposition temperature by ϳ300°C. Differential scanning calorimetry of the nanocomposite indicates that the polymer is confined to a restricted geometry because of the absence of a glass-transition temperature, which confirms the XRD finding. The IR absorption peaks corresponding to PVP and the expected PVP UV -* transition at 275 nm, along with the XRD and thermal data confirms that the gallery expansion is due to the PVP filament.

Vermiculite: Structural Properties and Examples of the Use

“…Differential scanning calorimetry of the nanocomposite indicates that the polymer is confined to a restricted geometry because of the absence of a glass-transition temperature, which confirms the XRD finding. The IR absorption peaks corresponding to PVP and the expected PVP of UV -* transition at 275 nm, along with the XRD, and thermal data confirms that the gallery expansion is owing to the PVP filament [132].…”

Preparation and properties of poly(vinyl alcohol)–vermiculite nanocomposites

“…Various methods have been proposed for the delamination of VMT. For example, VMT can be pretreated with a surfactant to produce an organoclay,35, 36 by the ion‐exchange method,33, 37 or by direct heating in a reactive vapor phase. In this work, we used the acid‐treatment route to delaminate VMT.…”

Structure and properties of polyamide‐6/vermiculite nanocomposites prepared by direct melt compounding

“…Vermiculite is widely used in the construction, horticultural, agricultural, and industrial markets. It is often used with binders such as Portland cement, polymeric resins, and high alumina cement 48. Therefore, it is advantageous to prepare low‐cost PA6–clay nanocomposites with good mechanical properties with vermiculite as a filler.…”