Studies on mechanical behavior high impact polystyrene/vinyl clay nanocomposites: Comparison between in situ polymerization and melt mixing

A comparative study on various synthesis methods like melt mixing (MM) and in situ polymerization (ISP) of high impact polystyrene/vinyl clay nanocomposites (HIPS/VNCs) is attempted here. In ISP, nanocomposites were prepared by mixing vinyl clay (VC) and poly butadiene rubber (PBR) in styrene with the initiator, azo bis isobutyronitryle. Melt compounding was conducted in two ways–commercial melt mixed blend where Commercial HIPS was mixed with VC and in situ melt mixed blend, where, nanocomposites were prepared by mixing polystyrene, PBR, and VC. The effect of dispersion of the nanoclay on the morphology and material properties of HIPS/VNCs was compared for all the methods, and it is found that the product obtained by ISP gives better properties when compared with MM. Moreover, the dispersion of the clay in the matrix is greater by in situ method, which is evident from X‐ray diffraction pattern and scanning electron microscopic analysis. Statistical analysis of ISP was carried out by design expert software version 8.0.7.1. Modeling and Optimization of the mechanical properties were done by using central composite design of response surface methodology. POLYM. COMPOS., 38:68–76, 2017. © 2015 Society of Plastics Engineers