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BACKGROUND: Reactive melt blends of poly(trimethylene terephthalate) (PTT) with a phenoxy resin (Ph) are some of the most interesting classes of reactive blends in which different kinds of exchange reactions can occur. This work is devoted to the study of these reactions and their effect on the rheological and morphological properties of the blends.RESULTS: The occurrence of transesterification reactions was confirmed by 1H NMR analysis. Scanning electron microscopy observations confirmed that all the blends, except PTT/Ph 90/10 (w/w), which exhibits a droplet‐in‐matrix morphology, are homogeneous. At the beginning of transesterification, the melt viscosity of the blends is more influenced by molar mass increasing reactions than by molar mass decreasing ones. After extension of the reaction time and increase in temperature the molar mass reducing reactions become predominant, which results in a reduction of the complex viscosities.CONCLUSION: This work provides new data on the transesterification reactions involving the secondary hydroxyl groups of phenoxy. The properties of PTT/Ph blends are strongly determined by the transesterification reactions, which on the one hand results in the formation of PTT‐grafted phenoxy chains and on the other hand a decrease in the molar mass of non‐bonded PTT. These reactions exert a distinct compatibilizing effect between the blend components. Copyright © 2008 Society of Chemical Industry

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Polyamide 6,6 (PA 6,6)/organically modified montmorillonite (OMMT) nanocomposites were prepared by a novel method, using direct interfacial polymerization of an aqueous hexamethylene diamine and a nonaqueous adipoyl chloride in dichloromethane solution containing different amounts of OMMT dispersed nanoparticles. The state of dispersion of OMMT in the PA 6,6 matrix was investigated by means of X-ray diffraction, as well as transmission electronic microscopy. The results indicated that the OMMT nanoparticles were dispersed homogeneously and nearly exfoliated in the PA 6,6 matrix. The random arrangement of clay platelets in the PA 6,6 matrix, exfoliation, and intercalation of clays between the PA 6,6 matrix were distinguished. The amount of the incorporated OMMT in the PA 6,6 matrix was determined by means of TGA technique. Furthermore it was found that addition of a small amount of OMMT dramatically improved the thermal stability of PA 6,6. The TGA thermograms of all the synthesized nanocomposite samples showed an interesting unexpected lag in the weight loss at high temperatures, which could be another evidence for formation of fully exfoliated nanocomposites structures, with improved thermal stability. Nucleating effect of the OMMT nanoparticles and their influence on crystallization behavior of PA 6,6 was confirmed by DSC. Finally it is concluded that the in situ interfacial polycondensation is a suitable method for synthesis of nanocomposites with well dispersed structures and enhanced properties. POLYM. COMPOS.,