Measurement of interfacial tension between polyamide-6 and poly(styrene-co-acrylonitrile) by breaking thread method

The measurement of the interfacial tension by the breaking thread method is known to be a proper method for high viscosity materials such as polymer melt. The interfacial tensions between polyamide-6 (PA-6) and a series of poly(styrene-co-acrylonitrile) (SAN) having AN contents varying between 0 and 41 wt% were obtained at 230°C by the breaking thread method. The interfacial tension has a maximum value at AN content of zero in the range of this study. It decreases rapidly at low AN content as AN content increases, and has minimum at ∼14% of AN content followed by increasing up to ∼28% AN. The interfacial tension increases slightly above ∼28% AN.