Polymer properties thermal stability

Bicerano J, "Prediction of Polymer Properties", "Thermal Stability", Marcel Dekker, New York, 3rd Ed, 2002, Chap. 16. 

Polyimide-clay nanocomposites constitute another example of the synthesis of nanocomposite from polymer solution [70-76]. Polyimide-clay nanocomposite films were produced via polymerization of 4,4 -diaminodiphenyl ether and pyromellitic dianhydride in dimethylacetamide (DMAC) solvent, followed by mixing of the poly(amic acid) solution with organoclay dispersed in DMAC. Synthetic mica and MMT produced primarily exfoliated nanocomposites, while saponite and hectorite led to only monolayer intercalation in the clay galleries [71]. Dramatic improvements in barrier properties, thermal stability, and modulus were observed for these nanocomposites. Polyimide-clay nanocomposites containing only a small fraction of clay exhibited a several-fold reduction in the... 

Fluoropolymers are among the most versatile plastics thanks to their properties. Thermal stability is a major feature of these polymers spurring their application where high temperature exposures are encountered. Fluoropolymers can produce toxic products if they are overheated. Precautions should be taken to remove any degradation fragments produced during the processing and fabrication of parts from fluoropolymers. 

Before irradiating a polymer, two kinds of additives could be incorporated. The first kind is that of radical scavengers (like hydroquinone, and more generally aromatic additives). Chen et al. studied the effect of four different aromatic additives on the radiation resistance of 60/40 styrene-ethylene/ butylene-styrene copolymer (SEBS)-PS blends. Considering the changes in mechanical properties, thermal stability and volume resistivity, pyrene was found the most efficient additive and diphenylacetylene (DPA) the worst. The authors concluded that the best protection effect could be attributed to... 

Although metallic and ceramic materials are used as membranes, polymeric materials account for the vast majority of commercial products. Polymer selection depends on a number of factors including intrinsic transport properties, mechanical properties, thermal stability, chemical stability (e.g., chemical resistance and biocompatibility), membrane manufacturability, cost, and patentability. The two most common types of polymers are glassy engineering thermoplastics and rubbery polysiloxanes. 

There are two types of rubber polymers natural mbber and synthetic mbber. Synthetic mbber is one type of artificial elastomer mainly synthesized from petroleum byproducts. It has good mechanical property, thermal stability, and compatibility with petroleum products. 

Because of their nanometer size, mbber clay nanocomposites exhibit markedly improved properties when compared to the pure polymers or their traditional composites. Most notable properties are increased tensile strength, tear strength, modulus, gas barrier properties, thermal stability. 

Ma C M, Lee C and Wu H (1998), Mechanical properties, thermal stability, and flame retardance of pultruded fiber-reinforced poly(ethylene oxide)-toughened novolak-type phenolic resin , J Appl Polym Sci, 69, 1129-1136. 

Among the entire potential nanocomposite precursors, those based on layered silicates have been most widely researched probably because the starting clay materials are easily available and environmentally friendly, due to their low cost, and because their intercalation chemistry has been studied for a long time [25], Biopolymer-clay nanocomposites are a new type of materials, which are prepared by adding low amounts of clay (1-5%) to the biopolymer matrix [26]. Montmorillonite is the most commonly used natural clay and has been successfully applied in numerous nanocomposite systems [13], Some studies have reported amelioration of mechanical properties, thermal stability, water absorption, and electrical, rheological, and morphological properties of alginate films via the incorporation of nanoclay into polymer matrices [27],... 

The van der Waals interactions in perfluoroplastics are extremely low. As a result, polytetrafluoroethylene (PTFE) has the lowest coefficient of friction of any known polymer. This property is due to the chemistry and structure described above which also give rise to the excellent electrical properties, thermal stability and chemical inertness. 

Regarding PEN nanocomposites, Si02-based systems have been developed since 2004 by Ahn, Kim, and Lee (2004), who surface-modified silica nanoparticles to improve their dispersion in the polymer during melt blending in an internal mixer. They reported on the increase of the elastic modulus and elongation at break at low nanoparticle content (0.4%wt). On the same nanocomposite system, Kim et al. showed an increase of several chemical-physical properties (thermal stability, dynamic mechanical behavior, and crystallization kinetics) after nanoparticle addition, and also a fourfold gain in the elastic modulus above the glass... 

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