Study the effect of solvent and nanoclay on poly (styrene-b-isoprene-b-styrene) (SIS)/ poly (styrene-co-methylmethacrylare) (PSMMA) polymer blends

Abstract

In this study various blends of Poly (styrene-b-isoprene-b-styrene) (SIS) and Poly (styrene-co-methylmethacrylate) (PSMMA) copolymers along with nanoclay composites, have been first time synthesized, characterized and studied for their improved properties. The SIS copolymer is a glassy-rubbery-glassy copolymer while PSMMA is a glassy-glassy copolymer. The SIS is very elastic and bearing less stress while PSMMA bears stress but not elastic as compared to SIS. The resultant blends of SIS/PSMMA increased the bearing stress capacity of SIS by reducing the elasticity. The Kao-DMSO clay was incorporated (as nanofiller) within SIS/PSMMA blend to form the nanoclay composites. Among various prepared blends, 20/80% SIS/SMMA blend ratio had exhibited maximum stress bearing property therefore was further employed to form the nanocomposites. The FTIR confirmed the successful formation of physical blends of these two copolymers and nanocomposites. Stress-strain curves of the blends and nanocomposites have been determined by mechanical testing. Glass transition temperatures were measured by DSC thermal analysis while thermal decomposition temperatures of blends and nanocomposites were investigated by TGA. The nanoclay composites (1,3,5 % nanoclay) were prepared in different solvents like THF and CHCl3 to study the effect of solvent on nanoclay composites w. These as-prepared copolymer blends-nanoclay composites have been subjected to measurement of same properties by similar techniques as been previously evaluated for pure blends. The blends have shown better properties than an individual components of the system while nanocomposites have exhibited further improved properties than blends. The SEM analysis was also carried out for the morphological studies which have corroborated that nanoclay fillers have reduced the phase separation of SIS/SMMA blends that results in improved properties.