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This paper focuses on the relation between the rheological and the morphological properties of immiscible polymer blends. Polystyrene droplets (PS) have been synthesized in the laboratory. The blends of EVA2840/PS at ratios 90/10, 70/30, and 50/50 (wt%/wt%) were prepared by Rheomix HAAKE 600VR internal batch mixer with roller rotor. Rheological tests were made at a temperature of 140 °C. Rheological measurements using a rotational rheometer with parallel-plate geometry are considered in order to lead to a better understanding of the dispersion of the PS droplets. Rheological examinations showed that the storage, the loss moduli, and the complex viscosity of blends have an extra elasticity at lower frequency. As a result, analysis of Han diagrams revealed that EVA2840/PS blend are immiscible.

This study deals with the behavior of a recycled polyethylene terephthalate (PET)/polypropylene (PP) blends. The compatibilizing effect has been investigated to examine the recycling feasibility in industrial production. The compatibilizing efficiency of olefinic copolymers containing epoxy groups for a/polypropylene (PET/PP) blends was examined using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), mechanical testing and rheological one. The effect of ethylene-glycidyl methacrylate (E-GMA, 92/8 wt%, Lotader AX8840) and ethylene–methyl acrylate-glycidyl methacrylate (E-MA-GMA, 68/24/8 wt%, Lotader AX8900) copolymers was investigated. The blends of PET/PP/compatibilizer at compositions 80/15/5, 85/11.25/3.75, 90/7.5/2.5 and 95/3.75/1.25 (wt%) were prepared by melt mixing in a single-screw extruder. Test specimens were prepared by compression moulding at processing temperatures of 250 °C. The incorporation of the compatibilizers has a large effect on the dispersion of the PP phase. Moreover, the copolymer was more efficient than the terpolymer. Especially, E-GMA was found to improve the elongation at break of the blends containing 80 % PET.

International audience; A reactive rotational molding (RRM) process was developed to obtain a PA6 by activated anionic ring-opening polymerization of epsilon-caprolactam (APA6). Sodium caprolactamate (C10) and caprolactam magnesium bromide (C1) were employed as catalysts, and difunctional hexamethylene-1,6-dicarbamoylcaprolactam (C20) was used as an activator. The kinetics of the anionic polymerization of epsilon-caprolactam into polyamide 6 was monitored through dynamic rheology and differential scanning calorimetry measurements. The effect of the processing parameters, such as the polymerization temperature, different catalyst/ activator combinations and concentrations, on the kinetics of polymerization is discussed. A temperature of 150 degrees C was demonstrated to be the most appropriate. It was also found that crystallization may occur during PA6 polymerization and that the combination C1/C20 was well suited as it permitted a suitable induction time. Isoviscosity curves were drawn in order to determine the available processing window for RRM. The properties of the obtained APA6 were compared with those of a conventionally rotomolded PA6. Results pointed at lower cycle times and increased tensile properties at weak deformation.

Lawsonia inermis L., (Lythraceae), commonly known as henna, Is a shrub or small tree frequently cultivated in India, the middle East, and along the African coast of the Mediterranean Sea (Hutchison and Dalzial 1954). Powdered leaves of this plant, in the form of a paste; axe used as a cosmetic for staining hands and hair. The dyeing property, as well as the antispasmodic (Fahim and Hossein 1954) and bacteriostatic properties (Hoffmann et al. 1947), were attributed to the presence of lawsone (1); a 2-hydroxy-l,4-naphthoquinone. The occurrence of gallic acid, flavonoids, coumarins, xan-thones, and phenolic glycosides in Lawsonia leaves has also been reported (Anand et al. 1992).

L'etude des proprietes rheologiques a l'etat fondu de materiaux composites a base de farines de bois ou de bois retifie et de polyethylene basse densite apolaire ou de copolymeres d'ethylene polaires, a ete effectuee a differentes vitesses de cisaillement. Le comportement des melanges varie avec le degre de torrefaction du bois et la nature polaire ou apolaire de la matrice. Une interpretation de ces differences de comportement, basees sur les interactions fibres-matrices, a ete proposee. Des mesures d'essais mecaniques, effectuees sur des eprouvettes composites, confirment les resultats presentes a l'etat fondu. // Investigation of the molten state properties of composite materials based on powdered pine or torrefied pines and low density polyethylene or ethylene copolymers is carried out at different shear rates. Mixtures with a polyethylene matrix exhibit a different behaviour compared to those based on copolymers. An interpretation of these differences based on fibre/matrix interactions is proposed. Mechanical tests carried out on composite test-bars corroborate the results obtained from the molten state.