Structural characterization of a series of novel bio-polyamides based on renewable raw materials-PA 4.10, PA 6.10, PA 10.10, and PA 10.12-was performed by Fourier transform infrared spectroscopy (FTIR) and wideangle X-ray diffraction (WAXD). Infrared spectra and the WAXD patterns indicate the coexistence of different crystalline forms, a-and c-triclinic and b-pseudohexagonal. Thermal properties in the glass transition (T g ) and melting region were then investigated using temperaturemodulated DSC (TOPEM Ò DSC). The melting point (T m ) was found to increase with increasing amide/methylene ratio in the polymer backbone, which is consistent with the increase in linear density of hydrogen bonds. Studies on the molecular dynamics by dynamic mechanical analysis show three distinct regions associated with the c-and the b-relaxation and the dynamic glass transition. TOPEM Ò DSC data reveal that at low frequency/long timescales, the materials with significantly different amide/methylene ratios have similar segmental dynamics.

This article presents an overview of the preparation and characterization of poly(vinyl chloride)/montmorillonite (PVC/MMT) nanocomposites. Different methods of PVC/MMT nanocomposite preparation are discussed. The incorporation of MMT into the PVC matrix results in an increase of thermal stability and induces changes in the mechanical properties. However, the properties of PVC/MMT nanocomposites depend strongly on the MMT organic modification procedure that governs the extent of MMT penetration by PVC macrochains and plays an important role with regard to the morphology formation. Flammability as well as other properties—barrier, optical, etc.—of PVC/MMT nanomaterials are also described. Finally, a future outlook is given. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers

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Polyhedral oligomeric silsesquioxane moieties with poly­(ethylene glycol) groups attached on the cage (PEG–POSS) were blended with an elastomeric polyurethane matrix, in contents up to 10 wt %. Several experimental techniques in agreement with each other show that the PEG–POSS moieties disperse well on the molecular level and act as diluents plasticizing the molecular dynamics. Although the degree of microphase separation is only weakly affected in all the compositions, changes in the macromorphology related to the POSS moieties have an impact on the matrix properties, decreasing the storage modulus. The PEG–POSS themselves display segmental dynamics, glass transition, and crystallinity; however, none of these properties are observed in the blends, providing additional support for excellent miscibility with the matrix. The results are compared to those of previous works where different synthesis approaches resulting in different POSS topologies were used.