Synthesis And Characterization Of Organic-Inorganic Films Based On The Composites Of Epoxidized Natural Rubber (Enr-50)/Polyaniline And Zirconia
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Date
2016-02
Authors
Mohammad, Hossein Azariyan
Journal Title
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Publisher
Universiti Sains Malaysia
Abstract
The current thesis focuses on the synthesis and characterization of novel Inorganic-Organic Composites (IOCs) materials with enhanced properties. Epoxidized natural rubber (ENR-50) was used as the polymer matrix and its composition with zirconium (IV)-n-propoxide and polyaniline (Pani) was investigated. The hydrogen bonding which contributes to the formation of the composite materials was observed by calorimetric and various spectroscopic analyses. Initially, ENR-50-zirconia hybrid films were synthesized through the sol-gel route by varying the amount of zirconium (IV)-n-propoxide ranging from 10 to 50 wt%. The prepared hybrid films exhibited very high optical transparency. With 30 wt% zirconium (IV)-n-propoxide addition, zirconia nanoparticles were uniformly and homogeneously distributed to the ENR-50 matrix with the particle sizes ranging from 50 to 70 nm. New composite materials from ENR-50 and polyaniline were successfully prepared using the solvent casting technique. Aniline was polymerized in the presence of dodecylbenzene sulfonic acid (DBSA). Subsequently it was added to ENR-50 for the preparation of ENR-50-Pani.DBSA (EPD) composite films. The SEM and electrical conductivity measurements revealed that the percolation threshold is at 2.5wt% of Pani.DBSA content. Nanoindentation results showed that the hardness and Young’s modulus increased with higher additions of Pani.DBSA polymer. In the third part of the work, novel Pani.DBSA/zirconia (PDZr) composites were successfully synthesized using the sol-gel technique. Upon incorporation of Zr (IV)-n-propoxide the resulting composite material showed greater crystallinity. Throughout the formation of PDZr composites the morphology changed and nanoparticles of Pani.DBSA formed rod-like structures in the resulting composite materials. A Higher electrical conductivity was obtained when the PDZr composite was incorporated with 30% weight of zirconium (IV)-n-propoxide. Eventually a novel ternary composite film composed of epoxidized natural rubber (ENR-50), Pani.DBSA and zirconium (IV)-n-propoxide (EPDZr) was designed taking a sol-gel approach. EPDZr composite has significantly higher electrical conductivity than EPD composite at the same loading of Pani.DBSA. The thermal stability of EPDZr composite decreased due to the catalytic effect of zirconia in ternary composites. XPS analyses were used to investigate the surface composition of EPD and EPDZr composites that provide further information about the interactions between ENR-50, Pani.DBSA and zirconia. The large spherical shape of Pani.DBSA becomes smaller with lower surface roughness in EPDZr30% with root mean square value of 2 nm.
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Keywords
Inorganic-Organic Composites