Abstract
An in‐depth study was carried out on the structure and properties of a series of poly(ethyl acrylate)/clay nanocomposites prepared by in situ atom transfer radical polymerization (PNCIs) with well‐defined molecular weights and narrow molecular weight distributions. Wide‐angle X‐ray diffraction and transmission electron microscopy studies revealed an exfoliated clay morphology, whereas conventional solution blending generated an intercalated structure. The storage moduli of the PNCIs showed a moderate increase over that of the neat polymer [poly(ethyl acrylate)]. The sample containing 4 wt % clay (PNCI4, where the number following PNCI indicates the weight percentage of clay) exhibited the highest improvement (31.9% at 25°C). In PNCIs, the β‐transition temperature showed a remarkable decrease (by 175% in PNCI4) along with a shift toward higher temperatures. This indicated the probability of the anchoring of the OH group of the clay layers to the >CO group of the pendant acrylate moiety, which was also confirmed by Fourier transform infrared analysis. Rheological measurements indicated a significant increase in the shear viscosity [by 9% in PNCI2, 15% in PNCI4, and 6% in the poly(ethyl acrylate)/clay nanocomposite with 2 wt % clay prepared by solution blending]. The PNCIs registered enhanced thermal stability, as indicated by the shift in the peak maximum temperature (388 and 392°C for the neat polymer and PNCI4, respectively) and a decrease in the rate of degradation (by 3.5% in PNCI2, 10.2% in PNCI4, and 49.3% in PNCI6). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008