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Immiscible polymer blends are interesting multiphase host systems for fillers. Such systems exhibit, within a certain composition limits, either a separate dispersion of the two minor phases or a dispersion of encapsulated filler particles within the minor polymer phase. Both thermodynamic (e.g. interfacial tension) and kinetic (e.g. relative viscosity) considerations determine the morphology developed during the blending process.The effect of interfacial characteristics on the structure‐property relationships of ternary polymer alloys and blends comprising polypropylene (PP), ethylene‐vinyl alcohol copolymer (EVOH) and glass beads (GB), or fibers (GF), was investigated. The system studied was based on a binary PP/EVOH immiscible blend, representing a blend of a semi‐crystalline apolar polymer with a semicrystalline highly polar copolymer. Modification of the interfacial properties was obtained through using silane coupling agents for the EVOH/glass interface and compatibilization using a maleic anhydride grafted PP (MA‐g‐PP) for the PP/EVOH interface. The compatibilizer was added in a procedure aimed to preserves the encapsulated EVOH/glass structure. Blends were prepared by melt extrusion compounding and specimens by injection molding. The morphology was characterized using scanning electron microscopy (SEM) and high resolution SEM (HRSEM), the shear viscosity by capillary rheometry and the thermal behavior using differential scanning calorimetry (DSC).The system studied consisted of filler particles encapsulated by EVOH, with some of the minor EVOH component separately dispersed within the PP matrix. Modification of the interfaces resulted in unique morphologies. The aminosilane glass surface treatment enhanced the encapsulation in the ternary [PP/EVOH]GB blends, resulting in an encapsulated morphology with no separtely dispersed EVOH particles. The addition of a MA‐g‐PP compatibilizer preserves the encapsulated morphology in the ternary blends with some finely dispersed EVOH particles and enhanced PP/EVOH interphase interactions.The viscosity of the binary and ternary blends was closely related to the blend's morphology and the level of shear rate. The treated glass surfaces showed increased viscosity compared to the cleaned glass surfaces in both GB and GF containing ternary blends.Both EVOH and glass serve as nucleating agents for the PP matrix, affecting its crystallization process but not its crystalline structure. The aminosilane glass surface treatment completely inhibited the EVOH crystallization process in the ternary blend.In summary, the structure of the multicomponent blends studied has a significant effect on their behavior as depicted by the rheological and thermal behavior. The structure‐performance relationships in the three‐component blends can be controlled and varied.

The effect of interface characteristics on the properties of three-component polymer blends comprising PP/EVOH/mica and PP/EVOH/glass beads (GB) was investigated (polypropylene-PP, ethylene-vinylalcohol-EVOH). The systems selected are based on the binary PP/EVOH immiscible blend representing a semi-crystalline apolar polymer (PP) and a semi-crystalline highly polar copolymer (EVOH), where PP serves as the matrix. A series of the binary and three-component blends with varying compositions was chosen to study the effect of the molding procedure, i.e. compression versus injection molding. The structures observed by SEM analysis consisted of the filler particles engulfed by the EVOH phase, with some of the minor EVOH component dispersed within the PP matrix. The effects of silane treatment (GB/EVOH interface) and compatibilization, using a maleated-PP compatibilizer (PP/EVOH interface), were studied in relation to the generated structures and properties. The compatibilizer was added in a unique procedure by which the encapsulated GB/EVOH structures were preserved. The characterization methods used included morphology by Scanning Electron Microscopy, thermal properties and crystallization behavior by Differential Scanning Calorimetry, mechanical properties by tensile testing, and dynamic characteristics by Dynamic Mechanical Thermal Analysis. The work has shown that structure-performance relationships in the three-component blends can be varied and controlled. P prising three and more component systems (polymers and fillers). A major characteristic of immiscible (phase separated) polymer blends is the multi-phase morphology, and its formation sensitivity to the processing conditions. Polymer blends offer an effective 'Moshe Narkis dedicates this article with best wishes to Tony DiBenedetto. a good friend with whom he has had fruitful collaboration since 1969. static and dynamic mechanical properties of the resulting products. Incorporation of a filler to a binary immiscible polymer system can lead to several morphologies: the filler particles may disperse in the matrix along with the minor dispersed polymer phase, the filler may latcate at the interfaces between the matrix and the dispersed polymer phase, the filler may be encapsulated by the minor phase. Immiscible blend systems exhibiting filler encapsulation are PP/PA-6 blends filled with 476

Low dielectric constant silica based films which incorporate a large amount of nanometer sized pores are attractive candidates as interlayer dielectrics in future gigascale integrated circuits chip technology. Nanoporous silica based films were deposited by surfactant templated self-assembly spin-on deposition (SOD). Other low-k materials with relatively low density silica based films were deposited by plasma enhanced chemical vapor deposition (PECVD), and some silica films were deposited by a CVD process. The SOD films have a higher porosity, compared to the PECVD/CVD films, as measured by x-ray reflectivity, Rutherford back scattering, and ellipsometry measurements. The SOD films have lower dielectric constants compared to the PECVD/CVD films, as derived from electrical (1 MHz) and optical (5×1014 Hz) measurements. The correlation between the dielectric constant and the porosity for the SOD films fits well to the lower prediction of the Lorentz–Lorenz model, and the PECVD/CVD films agree with the higher prediction of the Rayleigh model. These results suggest that the dielectric constant of the inhomogeneous two phase nanoporous silica based films deposited by SOD is significantly lowered by forming air voids, whereas the PECVD/CVD films consist of a homogeneous low density loose microstructure originating from the bonding nature alone, and therefore their dielectric constant is lowered to a smaller extent.

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