In this work, the morphologies of PMMA/PP/PS blends of different concentrations were studied and compared to the predictions of spreading coefficient, minimum free energy, and dynamic interfacial energy phenomenological models. Different morphologies than the ones predicted by the phenomenological models were observed in the case of PMMA matrix: a mixture of core-shell morphology (core of PP and shell of PS), dispersed PS, and subinclusions within the core when the concentration of PP was increased were obtained. The quantitative analysis of the morphologies indicated that when PMMA was the matrix, PS acted as an emulsifier. The study of the evolution of morphology in the case of 10/80/10 PMMA/PP/PS blends showed that when PMMA is added to the binary blend of PP/PS, threads of PMMA are formed and break up into droplets with a size comparable to the ones of PS forming a double dispersion type morphology, and then PMMA penetrates the drops of PS, forming a core-shell morphology with only one drop of PMMA inside a matrix. Subsequently, the core droplet of PMMA deforms and breaks up into smaller droplets.

SbstractThe main objective of this work is the study of the influence of microwaves devulcanization of the elastomeric phase on dynamically revulcanized blends based on Ground Tire Rubber (GTR)/High Density Polyethylene (HDPE). The devulcanization of the GTR was performed in a system comprised of a conventional microwave oven adapted with a motorized stirring at a constant microwaves power and at various exposure times. The influence of the devulcanization process on the final properties of the blends was evaluated in terms of mechanical, viscoelastic, thermal and rheological properties. The morphology was also studied.

No abstract

No abstract

In this work, a smectite clay from the State of Paraiba, Brazil, was treated with six different types of ammonium salts, which is an usual method to enhance the affinity between the clay and polymer for the preparation of nanocomposites. The clays, before and after modification, were characterized by X ray diffraction. The conformation of the salts within the platelets of the clay depended on the number of long alkyl chains of the salt. The thermal stability of the clays was also studied. The ammonium salts thermal decomposition was explained in light of their position within the organoclays.