Electronic absorption and fluorescence spectroscopies are applied to study the adsorption of rhodamine 3B dye on Laponite particles in aqueous suspensions. The adsorption on the clay favors the aggregation of the dye. The monomer and aggregates of rhodamine 3B can be adsorbed on both the external and the internal surfaces of Laponite, and their presence depends on the loading of the dye on the clay and the aging of the samples. The aggregation in the interlamellar space leads to the dimer and the trimer (or higher aggregates) of rhodamine 3B with a head-to-tail geometry. The comparison of the present results with those previously reported for the rhodamine 6G/Laponite system demonstrates the effect of the hydrophobicity on the adsorption of dyes in Laponite which affect not only the tendency of the dye to self-associate but also the geometric structure of the aggregates.

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SYNOPSISBlends composed of poly(ether imide) and poly(ethy1ene terephthalate) were obtained both by kneading followed by compression molding and by direct injection molding. Both procedures gave rise, probably a t all compositions, to biphasic structures with similar homogeneity that showed wide single Tg peaks by dynamic-mechanical analysis. The modulus of elasticity and the yield stress values appeared, respectively, close to and above those predicted by the additivity rule, probably due to the density increase and slight orientation observed. The ductility values against composition appeared well below the additive values, probably due to the presence of a dispersed phase together with the notch-sensitive nature of the blends.

Blends composed of poly(ether imide) and poly(ethylene terephthalate) were obtained both by kneading followed by compression molding and by direct injection molding. Both procedures gave rise, probably at all compositions, to biphasic structures with similar homogeneity that showed wide single Tg peaks by dynamic‐mechanical analysis. The modulus of elasticity and the yield stress values appeared, respectively, close to and above those predicted by the additivity rule, probably due to the density increase and slight orientation observed. The ductility values against composition appeared well below the additive values, probably due to the presence of a dispersed phase together with the notch‐sensitive nature of the blends. © 1996 John Wiley & Sons, Inc.

SYNOPSISBlends composed of poly (ethylene terephthalate) and a polyarylate have been melt-mixed and molded in a reciprocating screw injection-molding machine for different plasticization times. Interchange reactions between the blend components occur during processing and at a greater level as the plasticization time increases. These reactions led to a progressive homogenization of the blends as well as to a hindered crystallization of PET. The effect of the plasticization time on the mechanical properties of the blends seems to be a consequence of interchange reactions as well as of the degradation of the blends at the highest plasticization times. 0 1994 John Wiley & Sons, Inc.