Clay Minerals and Clay Mineral Water Dispersions — Properties and Applications

This chapter deals with the properties and applications of clay mineral water dispersions and clay minerals as flame retardant additives for polymers. Clay minerals, such as kaolinites, micas, and smectites, are the basic constituents of clay raw materials, which are classically employed in the ceramic industry to produce porcelain, fine ceramics, coarse ceramics, cements, electro-ceramics, tiles and refractories. These products are mainly used in sectors of economic importance, such as agriculture, civil engineering, and environment. A direct method to prepare clay mineral polymer composites is through dispersion in water. Water dispersions of clay exhibit some interesting flow phenomena such as yield stress; i.e., the material behaves as a solid until a critical force applied on the material forces it to flow. Water dispersions of clay have also been reported to be used to prepare materials with enhanced flame-retardant properties such as leather. On the other hand, direct melt compounding of clay mineral with different polymers as the composite matrix (HIPS, PP, and HDPE) to prepare a number of polymer composites with flame-retardant properties has also been reported

Estudio reológico a régimen transitorio de nanocompuestos poliméricos /

 tesis que para obtener el grado de Doctorado en Ingeniería, presenta Fausto Calderas Garcia ; asesor Octavio Manero Brito28 páginas : ilustracionesDoctorado en Ingeniería UNAM, Facultad de Química, 201

Assessment of extrusion-sonication process on flame retardant polypropylene by rheological characterization

In this work, the rheological behavior of flame retardant polypropylene composites produced by two methods: 1) twin-screw extrusion and 2) ultrasound application combined with a static mixer die single-screw extrusion is analyzed in detail; results are related to the morphology of the composites. The flame retardant polymer composites are composed of a polypropylene matrix, an intumescent flame retardant system and functionalized clay. Scanning electron microscopy revealed that the combination of the static mixer die and on-line sonication reduced particle size and improved the dispersion and distribution of the intumescent additives in the polypropylene matrix at the micrometric level. From linear viscoelastic properties, the Han, Cole-Cole and van Gurp-Palmen diagrams characterized the improved particle dispersion of the flame retardant additives. Two well-defined rheological behaviors were observed in these diagrams. These behaviors are independent on clay presence and concentration. In fact, the ultrasound device generates a 3D highly interconnected structure similar to a co-continuous pattern observed in polymer blends as evidenced by rheological measurements. This improvement in the dispersion and distribution of the additives is attributed to the combined effect of the static mixer die and on-line sonication that allowed reducing the additive content while achieving the optimum classification UL94-V0

Microencapsulación de ácido gálico en mucílago de nopal (Opuntia ficusindica) producido por secado por aspersión

Instituto Politécnico Nacional CIIDIR Unidad Oaxac

Microencapsulación de ácido gálico en mucílago de nopal (Opuntia ficusindica) producido por secado por aspersión

Instituto Politécnico Nacional CIIDIR Unidad Oaxac