Effect of styrene-methyl methacrylate/styrene-butadiene rubber on properties of poly(vinyl chloride)

Abstract

Generally, poly(vinyl chloride) (PVC) without the addition of plasticizer or impact modifiers is rigid and brittle. The aim of this research was to improve the mechanical properties of PVC using styrene-methyl methacrylate/styrene-butadiene compound (SMMA/SBR rubber) as an impact modifier. The compound was obtained commercially.  PVC containing SMMA/SBR rubber having SMMA/SBR phrs of 2.5, 5, 7.5 and 10 were prepared using two-roll mill set the conditions as follows: 170 ^oC and 5 min. Then, compression molding was carried out to prepare testing samples. FTIR analysis of SMMA/SBR rubber containing PVC samples showed the absorption band at 1732 cm^-1 (C=O stretching), 3025 cm^-1 (=C-H stretching) and 636.8 cm^-1 (C-Cl band). The effects of SMMA/SBR rubber on mechanical properties, including impact strength and tensile properties were evaluated by standard tests. The impact strength of SMMA/SBR rubber containing PVC increased significantly with an increase in the SMMA/SBR content (ex. SMMA/SBR 5 phr and 10 phr produced 3.30 and 6.38 kJ/m² respectively), resulting from the action of SMMA/SBR rubber phase as impact modifier as revealed by SEM images. Furthermore, modulus, tensile strength and elongation at break were investigated.