| Abstract
| - As-synthesized MCM-48 was modified via silylation with Cl−Si(CH3)3. The resultingsilylated MCM-48 possesses a well-ordered long-range structure, a narrow distribution ofnanosized pore diameters, a high mesoporous volume, a large specific surface area, and,most significantly, a hydrophobic surface. A nanocomposite structure based on silylatedMCM-48 and poly(vinyl acetate) (PVAc) has been prepared through both in situ polymerization and incorporation of preformed polymer. Characterization by FT-IR, XRD, and N2adsorption−desorption techniques indicates the latter method is more effective than the insitu polymerization method. The composites obtained by addition of the PVAc/silylated MCM-48 particles to a PVAc matrix have significantly enhanced mechanical performance, includingtoughness and elasticity, when compared with PVAc itself or with composites derived fromPVAc and pure silylated MCM-48 or precipitated silica.
- A nanocomposite structure based on MCM-48 and PVAc, in which the organic phase extends along the nanosized channels to the openings and is isolated by nano-dimensional inorganic pore walls, can be formed through in-situ polymerization of organic monomers inside the mesopores or introduction of preformed polymer into the mesoporous channels. When the resulting nanocomposites are used as additives with a polymer matrix they give rise to composites with significantly enhanced mechanical properties compared with those prepared with conventional inorganic particles.
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