Poly(vinyl chloride)/Multiwalled Carbon Nanotube Nanocomposites: Effect of the Tacticity Distribution on the Polymer/Nanofiller Interface

The preparation and characterization of nanocomposites of poly­(vinyl chloride) (PVC) of different tacticity with alkyl-modified multiwalled nanotubes (eMWNTs) is reported. Evidence from FTIR and thermal degradation measurements suggests that at the polymer–nanofiller interface specific isotactic conformations in the PVC chains are the preferred sites for the accommodation of eMWNTs through halogen bonding interactions, CO···Cl–C. The differences between the IR intensity ratio I₆₁₄/I₆₃₅ (related to the syndio/isotactic distribution) observed for the nanocomposite and the polymer increase as the isotactic content increases as a result of interaction with the nanotubes, which reduces the distribution of the isotactic conformation in the polymer matrix. Further, the improvements in thermal stability of the nanocomposites with respect to the pure polymer increase with the isotactic content since the eMWNT restricts mobility of the labile g+ttg– conformation especially located at the end of long isotactic sequences.