Barrier Properties of Filled High-impact Polystyrene

Tato práce je zaměřena na hodnocení vlivu různých druhů plniv o různých koncentracích v hPS na bariérové a mechanické vlastnosti. Cílem je srovnat vliv různých druhů (nano)plniv na propustnost pro plyny a vodní páru. Úroveň rozmíchání nanoplniva v polymerní matrici bylo stanoveno pomocí RTG analýzya TEM. Získané výsledky naznačují, že zde existuje korelace mezi velikostí částic nanoplniva a konečnými vlastnostmi. Některé vzorky vykázaly zlepšení bariérových vlastností.This work is focused on the evaluation of the effect of different kinds of fillers with various concentrations in high impact polystyrene on barrier properties, hardness and resilience. The aim is doing comparison of the effect of different kinds of fillers and nanofillers on gas and water permeability. Dispersion of nanofiller in polymer matrix was determined by X-ray diffraction and transmission electron microscopy. Gathered results indicate that there is a correlation between the size of the filler particles and final compound properties. Some samples showed an improvement of barrier propertie

Fire retardation of polystyrene/clay nanocomposites: Initial study on synergy effect

Polystyrene and its copolymers are a group of polymers with a wide field of applications. A major disadvantage among many of them is their high flammability. Previous research showed that one of the possibilities to reduce this negative property is to synergize conventional fire retardants and other types of fillers. Recent research showed that there is a synergy effect in clay-containing composites. This initial study is focused not only on the evaluation of synergy with modified or unmodified layered clay nanofillers but also on wide variety of other fillers such as clay nanotubes, melamine or magnesium hydroxide. All results are compared with pure polymer and polymer with conventional fire retardants. The samples were prepared in laboratory using Brabender Plasti-Corder kneader and analyzed by X-ray diffraction. Flammability was the most important property evaluated, and mechanical properties were also observed. © 2012 The Author(s)

Evaluation of synergy between conventional fire retardants and other fillers for polystyrene

Polystyren a jeho kopolymery patří do skupiny polymerů s širokým spektrem použití. Jejich velkou nevýhodou je vysoká hořlavost. Předchozí studie ukázaly, že jedna z možností jak tuto negativní vlastnost redukovat je využít synergického efektu mezi konvenčními retardéry hoření a jinými plnivy. Současný výzkum ukazuje, že jako jiné plnivo lze s úspěchem použít jílová nanoplniva. Tato práce je zaměřena na posouzení synergie nejen s těmito plnivy, ale také s dalšími, jako jsou jílové nanotrubičky, melamin nebo hydroxid hořečnatý. Všechny výsledky jsou porovnávány s čistým polymerem a vzorky s konvenčními retardéry hoření na bázi bromu. Vzorky byly připraveny v laboratorním hnětiči Brabender a analyzovány rentgenovou difrakcí. Hořlavost byla nejdůležitější zkoumanou vlastností a navíc byly posuzovány mechanické vlastnosti.Polystyrene and its copolymers are a group of polymers with a wide field of applications. A big disadvantage amongst many of them is high flammability. Previous research showed that one of the possibilities how to reduce this negative property is the application of synergy between conventional fire retardants and other fillers. Recent research showed that there is a synergy effect in composites with clays. This study is focused not only on the evaluation of synergy with modified or unmodified layered clay nanofillers but with wide variety of other fillers e.g. clay nanotubes, melamine or magnesium hydroxide. All results are compared to pure polymer and polymer with conventional fire retardants. The samples were prepared in laboratory Brabender kneader and analyzed by X-ray diffraction. Flammability was the most important evaluated property; moreover, mechanical properties were observed

The Mechanical and Optical Properties of the PVB Nanocomposites with Modified Nanofiller

Poly(vinyl butyral) (PVB) is an industrially important polymer used in laminated safety glass for its very high adhesion to glass and excellent optical properties. Clay nanofillers ? clays have been frequently used in recent research. In the case of PVB, there is a possibility to deteriorate its good optical and adhesive properties. Therefore this study is focused on evaluation of optical properties of PVB nanocomposites. These were prepared by kneading in Brabender, matrix was plasticized PVB with modified nanoclay montmorillonite as fillers, namely Cloisite Na+. The nanoclay was modified by a grafting methodthree different types of intercalation agents were used for the modification, 3-minopropyltriethoxysilane (APS), trimethylchlorosilane (TMCS) and octyltrimethoxysilane (OTMS). The modification of nanoclay was done in the proportion of nanoclay to silanes - 1:0.3. The samples were compared with pure PVB and nanocomposites with commercially modified montmorillonite, Cloisite 30B. Films of the composites were prepared by hot press molding. All nanocomposite samples had loading 0.5, 1, 2 and 3 of nanoclay. The materials were characterized by X-ray diffraction (XRD), optical microscope, tensile test and spectrophotometer. XRD determined that PVB nanocomposites reached intercalated/exfoliated structure. The Break stress of PVB nanocomposites was increased for most nanofillers. The light transmission of the PVB nanocomposites was analyzed by spectrophotometer. The data showed that the light transmission decreases with increasing loading level of nanoclay and the light transmission was significantly different for every nanofiller

Shape and size of filler vs. mechanical properties and flammability of polystyrene nanocomposites

Presented work deals with the evaluation of the connection between the shape of (nano)filler and the polystyrene (nano)composites. Fillers and nanofillers with various type of particles (spherical, tubes, layered...)were chosen for the preparation of PS composites and nanocomposites. All samples were prepared by the compounding i.e. by the mixing in the melt of PS. Morphology and the level of distribution was evaluated by XRD and TEM. Next flammability and mechanical properties were observed. The best result was achieved with the layered mineral nanofiller Cloisite Na+