Characterization of poly(vinyl chloride) compounds containing different levels of starch

Abstract

Despite poly(vinyl chloride) (PVC) being one of the most useful materials available to the fabricator, its inadequate disposal has contributed to strong noneconomic issues based on the allegedly evil effects of chlorine. In this study, we examined the influence of adding starch, a biodegradable bioplastics, to mixtures of PVC plasticized with di(2‐ethylhexyl) adipate (which is susceptible to fungal attack). PVC and its mixtures were assessed by mechanical properties, differential scanning calorimetry, Fourier‐transform infrared spectroscopy, low‐field nuclear magnetic resonance, thermogravimetric analysis, optical microscopy, and degradation in simulated soil. Increasing the amount of starch in the mixtures resulted in greater material stiffness, with a reduction in tensile strength at break (σ) and elongation at break (ɛ). Fourier‐transform infrared spectroscopy and nuclear magnetic resonance showed that there was limited interfacial interaction between components of the PVC mixtures, which agreed with slight phase separation (breakage of the interfaces) and the decrease in the values of σ and ɛ for the mixtures. Samples containing a larger content of starch showed little weight loss after 2, 4, and 6 months in simulated soil, possibly because the starch was encapsulated by the PVC resin. J. VINYL ADDIT. TECHNOL., 22:396–404, 2016. © 2015 Society of Plastics Engineers