Preparation of exfoliated clay/polymer nanocomposites via organosilane grafting and in situ ATRP of glycidyl methacrylate

Clay/polymer nanocomposites, of the type montmorillonite/poly(glycidyl methacrylate) (MMT/PGMA), were synthesized via atom transfer radical polymerization (ATRP). MMT was amino‐silanized and then reacted with 2‐bromoisobutyryl bromide (BIB) to provide NH‐C(‐C(CH3)2Br groups attached to the clay. The latter (MMT‐SiBr) served as macroinitiator for the in situ ATRP of GMA. The resulting MMT/PGMA nanocomposites were found to be highly exfoliated, as judged by X‐ray diffraction (XRD) measurements. Thermogravimetric analysis (TGA) and XPS analyses suggest that the nanocomposites have PGMA‐rich bulk and surface. Indeed, the mass loading of PGMA reached 65 wt. % while XPS spectra, particularly the high‐resolution C1s region, resemble those of pure PGMA. These clay/PGMA nanocomposites are suitable as nanofillers for epoxy adhesives, since PGMA chains are both compatible with epoxy resins and reactive towards crosslinkers via the pendant glycidyl groups from PGMA grafts.