%0 Journal Article
%T Thermal Stability and Kinetic Study of Isotactic Polypropylene/Algerian Bentonite Nanocomposites Prepared via Melt Blending
%A Fay£¿al Benhacine
%A Farida Yahiaoui
%A Assia Siham Hadj-Hamou
%J Journal of Polymers
%D 2014
%R 10.1155/2014/426470
%X Isotactic polypropylene (iPP)/bentonite nanocomposites were prepared via melt blending using bentonite clay originated from Maghnia (Algeria). This clay was, at a first stage, used in its pure form (PBT) and then organically modified by Hexadecyl ammonium chloride (OBT). The effect of Maghnia bentonite dispersion on the iPP matrix was investigated by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). DSC results evidenced that unmodified or organomodified bentonite can act as a nucleating agent increasing the rate of crystallites formation. Moreover, a thermogravimetry analysis confirmed a significant enhanced thermal stability of IPP/clay nanocomposites compared to pure IPP. The Flynn-Wall-Ozawa and Tang methods were applied to determine the activation energy of the degradation process. The apparent activation energy£¿£¿ of thermal degradation for IPP/clay nanocomposites was much higher than that of virgin iPP. Comparatively to PBT, results indicate that OBT has an important effect on pure iPP thermal stability. Tensile modulus, tensile strength, and elongation at break were also measured and compared with those of pure iPP. 1. Introduction Isotactic polypropylene (iPP) is one of the most interesting commodity thermoplastic accounting for about 20% of the total world¡¯s polyolefin production, not only for its balance of physical and mechanical properties but also for its environmental friendliness (recyclability) and low cost. It is widely used in many applications, such as fibers, films for food packaging, bottles production, and tubes. Isotactic polypropylene (iPP)/clay composites are among the pioneer researched nanocomposites because iPP is one of the most widely used polyolefins, and its properties are greatly affected by clay dispersion in the polymer [1¨C10]. Many researches were reported on preparation and characterization of polypropylene (iPP)/clay nanocomposites, focusing on the dispersed morphology of clay particles [11¨C14]. Polymer degradation is the purpose of many researches on plastic waste management. The knowledge of degradation kinetics of polymers is important for modeling the degradation process. Several mechanisms were proposed to describe thermal and flame properties of polymer/clay nanocomposites. Generally, the barrier effect of clay layers for heat and volatiles plays a key role in these enhancements. Kinetic data reflect that improvement of thermal stability of polymer/clay nanocomposites is associated with an increase in the activation energy of their degradation; this is explained by the barrier effect
%U http://www.hindawi.com/journals/jpol/2014/426470/