Organoclay thermal stability

Several efforts have been reported to synthesize new organoclays to improve organoclay thermal stability, while enhancing the interaction between polystyrene and the modified clay. Organoclays prepared from phosphonium, stibonium or imidazolium cations have been employed in such studies [3-5]. Although evidences suggests that clay dispersion and the improvement in nanocomposite properties depend on the surface... 

In the matrix of PLA/ polycaprilactone (PCL)/OMMT nano-composites, the silicate layers of the organoclay were intercalated and randomly distributed (Zhenyang et at, 2007). The PLA/PCL blend significantly improved the tensile and other mechanical properties by addition of OMMT. Thermal stability of PLA/PCL blends was also explicitly improved when the OMMT content is less than 5%wt. Preparation of PLA/thermoplastic starch/MMT nano-composites have been investigated and the products have been characterized using X-Ray diffraction, transmission electron microscopy and tensile measurements. The results show improvement in the tensile and modulus, and reduction in fracture toughness (Arroyo et ah, 2010). 

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... 

Measures have been taken to improve the thermal stability of the organoclays. Extraction of excess modifier can improve the thermal stability of alkyl ammoniums, sometimes with improvements up... 

A. Laachachi, E. Leroy, M. Cochez, M. Ferriol, and J.M. Lopez-Cuesta, Use of oxide nano-particles and organoclays to improve thermal stability and fire retardancy of PMMA, Polym. Degrad. Stabil., 2005, 89 344. 

Following obtained data authors draw the conclusion that the optimal results for thermal properties ate being obtained if 2 wt% of the organoclay is added [11,12,19], The great number of studies on the polymeric composite organoclay-based materials show [11-13,19] that the inclusion of the inoiganic component into the organic polymer improves the thermal stability of the latter, see Tables 3 and 4. 

It is impossible to give an exact answer on the question about how the refractoriness of organoclay - based nanocomposites increases basing on only the upper experimental data but the obvious fact is that the increased thermal stability and refractoriness are due to the presence of the clays existing in the polymeric matrix as... 

PP nanocomposite toughened with poly (ethylene-co-octene) using PP-g-MAH (6 wt%) as compatibilizer Thermal stability of the rubber-toughened PP nanocomposites was studied Thermal stability was improved significantly with the addition of small amount of organoclay Lim et al. 2006... 

PBT/HDPE PBT 1 to 90 wt% Nanofil 919 PBT phase and interface based on blend composition The MMT particles located at the blend interface reduce the interfacial tension between blend components. The addition of organoclay also increases the thermal stabilization of blend morphology Hong et al. 2006a, b... 

Shojaei and Faghihi [20] studied the effect of different concentrations of organoclay on styrene-butadiene mbber and phenolic resin blends prepared by two-roll mill. Thermogravimetric studies indicated that the organoclay enhanced the thermal stability of styrene-butadiene rubber vulcanizate, whilst manifesting a catalytic behavior in presence of the phenolic resin. 

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