Compatibilisation of blends of poly(vinyl chloride) and poly(styrene-block-(ethylene-co-butadiene)-block–styrene) with maleic anhydride grafting

Abstract

The mechanical properties of blends of poly (vinyl chloride) (PVC) and poly (styrene-block-(ethylene-co-butadiene)-block-styrene) (SEBS) were investigated using maleic anhydride grafted SEBS (SEBS-g-MAH) as a compatibiliser. The results indicated that addition of a small amount of SEBS-g-MAH during melt blending significantly improved the mechanical properties of PVC/ SEBS blends. The impact strength of the compatibilised PVC/SEBS blends was found to reach a maximum of 53 . 5¡2 . 78 KJ m 22 at room temperature and a maximum of 32 . 8¡1 . 66 KJ m 22 at 220uC at an SEBS-g-MAH loading level of 6 phr. The two glass transition temperatures of the components in the blends converged to some degree upon addition of SEBS-g-MAH for compatibilisation. At room temperature the dynamic storage modulus of the compatibilised blends was higher than that of the blends without compatibilisation. The size of the dispersed phase domains in the blends was appreciably reduced on addition of SEBS-g-MAH during melt blending according to scanning electron microscopy. All the above observations revealed that SEBS-g-MAH enhanced the compatibility between PVC and SEBS in the PVC/SEBS blends.