clay

The heat-and-mass transfer during filtration drying of feedstock for slag gravel production. Research of change of temperature of thermal agent is on height of layer of material

In the article the results of experimental and theoretical researches are presented heat- and mass-transfer during the filtration drying of feedstock for slag gravel production. Time-history of temperature of thermal agent is experimentally investigational on the height of layer of dry and moist raw material materials and dependence of speed of moving of mass-transfer zone is certain on a temperature.

Effect of Extrusion Processing Variables in the Polyethylene/Clay Nanocomposites Rheological Properties

In this work, high density polyethylene, HDPE, was compounded in a twin screw extruder with organophilic treated montmorillonite clay and a compatibilizer agent. The screws configuration was changed from distributive to highly dispersive [1], using four different profiles. The extrusion conditions were also changed. The exfoliation degree was evaluated by X-rays. The rheological measurements showed different behavior according to the processing adopted.

Brazilian Mineral Clay as Support for Metallocene Catalyst in the Synthesis of Polyethylene

Silica was compared with clays as supports for metallocene. Ethylene homopolymerization with both homogeneous and heterogeneous catalysts was performed. Activation energy was higher for
(n-BuCp)2ZrCl2/SiO2/MAO, although high activities were obtained for catalysts with clay. They showed Ea close to that of homogeneous precursor. Catalyst/clay control polymer morphology until 363 K

 

The Use of Solid State NMR to Characterize High Density Polyethylene/Organoclay Nanocomposites

Recently the development of new materials, in special polymeric nanocomposites, formed by polymer and layered silicates, have gained attention. In this work nanocomposites based on high-density polyethylene matrix (HDPE) and organically modified clay were prepared by melt processing and characterized by the determination of proton spin-lattice relaxation time through solid state nuclear magnetic resonance (NMR) spectroscopy.

Preparation of Modified Montmorillonite with Benzethonium and Benzalconium Chloride for Nanocomposites Preparation

Modified clays were intercalated with benzethonium chloride and benzalkonium chloride by exchanging the sodium ions. The organoclays obtained were characterized by X-ray diffraction (XRD); thermogravimetric analysis (TGA) and low field nuclear magnetic resonance (NMR), through proton spin-lattice relaxation time measurements (T1H). From the characterization data, the formation of organically modified clays was confirmed. These products can probably be used to prepare PVC nanocomposites with superior processing characteristics due to better chemical structure of clay surfactants.