Properties of Recycled Poly(vinylchloride)/ Acrylonitrile-Butadiene Rubber Blends: The Effect of Maleic Acid

Abstract

Maleic acid (MAc) was used to improve the compatibility of recycled poly(vi nylchloride)(PVCr)/acrylonitrile-butadiene rubber (NBR) blends. Virgin PVC (PVCv) blends with NBR were also prepared for comparison. The blends were melt mixed using a Haake Rheomix Polydrive R 600/610 at 150 °C and a rotor speed of 50 rpm. It was found that the maleic acid significantly improved the PVCr/NBR blends properties. At a similar blend composition, the PVCr/NBR + MAc blends exhibited a higher peak stress and a higher stress at 100% elongation (M₁₀₀) but a lower elongation at break and a lower swelling index than ordinary PVCr/NBR blends. Scanning electron microscopy (SEM) of the tensile fracture surfaces of the blends indicated that the maleic acid increased the interfacial interaction between the PVCr and NBR phases, thus improving their compatibility. Differential scanning calorimetry (DSC) indicated that the PVCr/NBR with MAc incorporated had a higher T_g than the PVCr/NBR and PVCv/NBR blends.