The Interassociation Equilibrium Constant and Thermodynamic Properties of Phenolic Resin/Polyamide 6 Blend

Abstract

The interassociation equilibrium constant and interaction behavior between OH and amide group in phenolic resin/polyamide 6 blend have been investigated. There is a very strong intermolecular hydrogen bonding in the phenolic/polyamide 6 blend. KA = 639.64 is calculated from the Painter-Coleman association model (PCAM). Quantitative description of the intermolecular hydrogen bonding number resulted from solid FTIR spectra is rather close to that predicted by PCAM. The self-association of polyamide 6 is replaced by the interassociation in the phenolic rich region. The phenolic resin/polyamide 6 blend is miscible and phase separation does not occur throughout the blend range from room temperature to molten state, causing a high KA value. The Tg deviation of phenolic resin/polyamide 6 is negative throughout the blending range. The phenolic–polyamide 6 interaction formed is not large enough to overcome the breaking off of the self-association of phenolic resin and polyamide 6. It is attributed to the long repeated unit of polyamide 6 which hinders the self-association of phenolic resin, especially on phenolic rich region, consequently, increasing the entropy of polymer blend.