Synthesis and evaluation of functional polymeric additives with urethane linkage as dispersing agents for preparation of pigment concentrates with high solid loading, low-VOC content, and usefulness for industrial coatings

摘要

A synthetic strategy based on precursor and prepolymer approaches has been adopted for preparing the functional polymeric agents with urethane linkage and functional groups such as -CONH-, -COOH, -NH-, C-N, -COOR and C-Cl, that can interact with the pigment surfaces. The agents were tested for their dispersion capacity. High pigment-loaded (as high as 64%) and solvent-free stainers with potential applications in low-VOC paints were successfully prepared. The stainers were mixed with two commercial binder resins-namely epoxy base white and polyurethane metal coat binder resins-to get first paints and their coats on various substrates such as standard glaze paper, tin and mild steel panels. The paint-specific properties, viz. percentage opacity, color strength, solvent resistance, adhesion, scratch hardness and salt spray resistance, were measured to adjudge the suitability of high pigment-loaded coats in industrial applications. The properties measured in general snowed improvement in spite of the increase in the pigment loading. The paint coats resisted not only the xylene, petrol, and lubricating oil attack but also humidity and salt spray (up to 1000 h of exposure).