Polylactide/polyethylene blends (PLA/PE) and their nanocomposites were prepared via the melt blending process. The effects of organoclay, compatibilizer (PE‐g‐MA), and PE content on morphology, linear viscoelastic properties of the melt and cold crystallization of the samples have been studied. The Palierne model is applied to predict the rheological behavior of unfilled blends. It implies that there is a quantitative agreement between model and experimental data for low PE content blend. From WAXD and the rheological behavior, it is shown that organoclay exhibits a higher extent of intercalation and dispersion in PLA/PE/organoclay nanocomposite than in PLA/organoclay nanocomposite. The DSC results present that the addition of compatibilizer into blend nanocomposite increases cold crystallization temperature of PLA by about 3°C. This can be explained by the role of compatibilizer in transfer of a part of organoclay from PLA matrix to droplets resulting in increase of PLA chain mobility and, therefore, slightly greater cold crystallization temperature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41300.

In the present study, zinc oxide nanoparticles (ZnO-NPs) were synthesized by a hydrothermal method followed by the fabrication of polylactic acid/polycaprolactone blend (PLA/PCL, 80/20 wt/wt) at various loadings of ZnO-NPs (2, 4, and 6 wt%) via melt mixing. FTIR and XRD patterns confirmed that the ZnO-NPs were successfully synthesized. The ZnO-NPs with an average diameter of about 46–73 nm were observed by the FESEM analysis. The effect of ZnO-NPs on morphological, thermal, UV absorption, mechanical, photochemical degradation, rheological and cell viability properties of PLA/PCL blend were investigated. FESEM micrographs of bionanocomposites demonstrated that polycaprolactone was dispersed as a droplet to the Polylactic acid matrix phase. DSC analysis showed that the addition of ZnO-NPs increased the degree of crystallinity and melting temperature of the PLA. Mechanical assessment of the bionanocomposites reveals that the addition of 2, 4 and 6 wt.% of ZnO-NPs into the blend sample leads to increase in the tensile modulus by about 5.4, 11 and 24%. The MTT assay results implied that cell viability of the both filled and unfilled samples is greater than 90% indicating their biocompatibility to the fibroblast cells. It is observed that the melt linear viscoelastic properties of the prepared bionanocomposites are under control of LA/PCL chain degradation and hydrodynamic nanoparticles interaction.

The effects of compatibilizer and the type of polyethylene (PE) matrix on structure development of PE/organoclay nanocomposite samples were investigated by means of X-ray diffraction technique and transmission electron microscopy in conjunction with melt viscoelastic measurements. It was shown that the presence of compatibilizer plays a key role in determining the extent of intercalation and resulting structure development in both linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE). The LLDPE/organoclay nanocomposite samples exhibited a pronounced low-frequency nonterminal storage modulus whose values were found to be greater than those of LDPE/organoclay nanocomposite samples. The percentage increase in storage modulus values for the compatibilized LLDPE/organoclay nanocomposite sample compared to the virgin LLDPE sample was 1080, while the percentage increase in storage modulus values for the compatibilized LDPE/organoclay nanocomposite sample compared to the virgin LDPE sample was 200, at frequency 0.1 s À1 . The melt viscoelastic measurements performed on the nanocomposite blown film samples indicated that at higher draw-down ratio the organoclay platelets and/or tactoids were aligned in the flow direction. Comparing the melt viscoelastic results obtained for annealed and unannealed nanocomposite blown film samples, it was demonstrated that the reorientation of the induced organoclay alignment, which led to network structure formation in the amorphous phase of PE, is very slow, and the time required to complete the reorientation was found to be longer than 3 h at annealing temperature (100 C). V C 2012Wiley Periodicals, Inc. J Appl Polym Sci 125: E435-E444, 2012

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-The purpose of this study is to examine the effect of solid loading and aggregate size on the rheological behavior of PDMS (polydimethylsiloxane)/CC (calcium carbonate) suspensions. Mixtures containing 10 to 40 vol% of CC were prepared; the effect of shear rate and particle content on aggregate size and rheological properties was studied. Rheological properties including viscosity, loss modulus, storage modulus and yield stress were measured using rotational and oscillatory rheometry. Casson's equation was found to satisfactorily model the samples' stress response as a function of shear rate for different solid content. While solid content did not have any effect on the aggregate size, shear rate did influence the aggregate median diameter. It was observed that suspensions with higher aggregate size had a higher viscosity. In general, for a given volume fraction, a small change in the aggregate size had a significant impact on the viscosity, particularly at low shear rates.