Sunday, August 11, 2019
Thermoplastic polyester elastomer nanocomposites Assignment
Thermoplastic polyester elastomer nanocomposites - Assignment Example It also shows very good resistance to impact, tear, creep, and abrasion. Inorder to improve to improve mechanical, therma and electrical properties of TPEs (Aso 2006, 2854) fillers such as mica, clays, silica, kaolin, and talc are added (Sreekanth 2009, pg. 272). Mica improves critical properties of TPEs, these properties are cost effective . which are cost effective (Sreekanth 2009, pg. 272). This position has also been supported by LeBaron et al. (1999, pg.12) who argues that composites that show a change in structure and composition over a nanometer length always exhibit property enhancements in comparison to conventioanally scaled composites. Layered silicates which have been distributed as a reinforcing phase on a polymer matrix are an example of such mixture of inorganic/organic nanocomposites (LeBaron et al.1999, pg.12). Some of these enhanced properties are, increased moduli, increased heat resistance and strength, and also decreased flammability (Ray et al. 2003, pg. 2355). For example, in a nylon layered silicate with 2 % with volume of inorgan ic content, doubling of strenghth and tensile modulus is achieved (Giannelis 1997, pg. 675). The reason why nanocomposites exhibit improved characteristics as compared to conventional composites is because the dispersion of clay nano layers increases the number of reinforcing elements available that can deflect cracks (LeBaron et al.1999, pg.13). Coupling between polymer matrix and the large surface area (760 m2/g) increases stress transfer to the reinforcement phase, which enable toughning and tensile improvement by (LeBaron et al.1999, pg.13). In addition, layered silicates thickness are in the order of 1 nm and they also have high aspect ratios in the magnitude of (10-1000) (Ray et al. 2003, pg. 2355). There are various reasons why there is an increase in the high aspect ratios of the nanocomposites.According to Yano et al. (1993), it is possible that the improved barrier
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