Application of Taguchi approach in describing the mechanical properties and thermal decomposition behavior of poly(vinyl chloride)/clay nanocomposites: Highlighting the Role of organic modifier

Mechanical and thermal properties of poly(vinyl chloride) (PVC)/nanoclay (NC) composites prepared via melt-blending in a single-screw extruder were investigated. The effects of NC type, NC content, and K-value of PVC were evaluated by using L9 orthogonal array of the Taguchi approach. The most influential variables and significance of interactive effects were examined for the highest values of Young's modulus and hardness. Scanning electron micrographs and X-ray diffraction patterns revealed the formation of exfoliated/intercalated structures. Although the K-value has a minor individual effect on mechanical characteristics, the interaction of the K-value with NC type and NC content is significant. The composites were also characterized and tested by using analysis by thermal gravimetry, differential thermogravimetry, and differential scanning calorimetry methods. The results of the thermal studies indicated that decomposition of the organic modifier of NCs has a catalytic effect on the dehydrochlorination of PVC. This finding justifies the rather low mechanical properties of PVC/organoclay nanocomposites. Fourier-transform infrared spectra of the samples were indicative of accelerated degradation reactions, which provided support for above observations. J. VINYL ADDIT. TECHNOL., 22:182-190, 2016. (c) 2014 Society of Plastics Engineers