Development and Characterization of PVC/ABS Polyblends

This paper discusses about the development and nature of property relationships generated by blending a low cost homopolymer (PVC) with ABS terpolymer. The blend properties are strongly influenced by the phase behaviour of the constituents which is due to interactions among them. PVC/ABS blends are microheterogeneous: they have a rigid matrix with soft dispersed phase but are mechanically compatible. Because of this partial compatibility, additive responses are observed (as a function of blend ratio) in tensile strength and modulus, flexural strength and modulus and viscosities. The mutual interaction also accounts for positive deviations of experimental specific gravities from empirically calculated ones, using the values for PVC & ABS alone. The pay-off for blending comes from “synergistic” improvements in the impact strength of PVC/ABS blends, which undoubtedly comes from the presence of discrete elastomeric phase. PVC/ABS blends are attractive not only due to their high impact but offer “built-in” flame retardance, moderate cost, good processability, high gloss etc.