Rheological Behavior, Tensile Properties, Morphology, and Thermal Stability of Recycled Poly(vinyl chloride)/Acrylonitrile Butadiene Rubber (PVCr/NBR) Blends: The Effect of Maleic Acid

Abstract

Blends of recycled poly(vinyl chloride) (PVCr) and acrylonitrile butadiene rubber (NBR) modified by addition of maleic acid (MAc) are prepared by using a Haake Rheomix. The effect of MAc on melt Rheological behavior, tensile properties, morphology, and thermal stability of PVCr/NBR blends are investigated. The recorded data obtained from the Haake Rheomix are converted into values of apparent shear rate, apparent shear stress, and apparent viscosity. The apparent viscosity of the blends is found to decrease with increase in the shear rate and follow the pseudoplasticity behavior. At a similar shear rate, the presence of MAc in PVCr/NBR blends exhibits higher apparent viscosity than PVCr/NBR blends without MAc. Activation energy, Ea decreases with increasing shear rate, obviously due to the strong non-Newtonian behavior of PVCr/NBR blends. The addition of MAc in PVCr/NBR blends exhibits higher stress at peak and stress at 100% elongation but lower elongation at break and thermal stability than PVCr/NBR blends without the addition of MAc. Scanning electron microscopic (SEM) examination of extracted surfaces of PVCr/NBR+MAc blends indicates the increase of the interfacial interaction between PVCr and NBR phases with the presence of Mac.