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The size of phosphate-glass (Pglass) particles dispersed in a polyamide-6 (PA6) matrix by melt blending has been characterized by 1 H-31 P solid-state nuclear magnetic resonance (NMR). 1 H spin diffusion from ∼75% of the 1 H in the glass to the polyamide is observed within 50 ms, indicating proximity on a 30 nm scale. Fast dephasing of a quarter of the 31 P magnetization by dipolar couplings to polyamide protons in 31 P{ 1 H} heteronuclear recoupling with dephasing by strong homonuclear interactions of protons (HARDSHIP) NMR shows that ∼25% of the Pglass is within 0.5 nm from the polyamide. This is confirmed by 1 H-31 P heteronuclear correlation NMR spectra with inverse T 2,H filtering, which document relatively fast (1 ms) cross polarization from PA6 protons, identified by their upfield chemical shift and short transverse relaxation time T 2,H , to a significant fraction of 31 P in the glass. The 31 P spectrum associated with the polyamide 1 H reveals that the phosphate sites near the polyamide matrix are chemically altered but differently than previously observed in Pglass-polyethylene hybrids, where no such contact was proven. As expected, the 31 P sites that cross-polarize from the polyamide protons also exhibit pronounced dephasing in 31 P{ 1 H} HARDSHIP experiments. HARDSHIP experiments after cross polarization and 31 P spin diffusion experiments indicate that the ∼25% of phosphate that is within 0.5 nm from the polyamide is not dispersed in the polymer but on the surface of ∼10 nm diameter Pglass particles. This study represents the first conclusive evidence of intimate mixing of the hybrid components. Further, it suggests that this is an excellent model system for exploring new routes for driving organic polymers and inorganic glass to self-assemble into useful organic/inorganic hybrid materials.

The miscibility, crystallization kinetics, and mechanical properties of a novel low T g phosphate glass (Pglass)/polyamide 6 hybrid material were investigated. Here, we report the first evidence for miscibility of inorganic phosphate glass and organic polymer prepared by blending both components in the liquid phase using conventional polymer processing methods. From classical melting point depression measurements, we obtained a chi interaction parameter (v) of À0.067 for the Pglass/polyamide 6 hybrid, indicating that the inorganic glass and polyamide 6 are miscible. The crystallization kinetic parameters for the hybrids were determined using the Avrami approach and found to depend on the volume fraction of Pglass present in the system. In addition, we studied both the dynamic and static mechanical behavior of the hybrids. The results showed a single T g that decreased by up to 10 8C with increasing phosphate glass volume percent for the hybrids, giving further evidence for the hybrid component miscibility and plasticizing action of the phosphate glass in the pure polyamide 6, respectively. The tensile (static) mechanical properties of the hybrids were found to be remarkably similar to those obtained from typical polymers plasticized with relatively low molecular weight compounds. V V C 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 441-450, 2006

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