Nanoclay-modified polypropylene dyeable with acid and disperse dyes

Nanoclay (montmorillonite, (OH ₄Si₈Al₄O₂₀n H₂O) modified with quaternary ammonium salt was used to make nanocomposite polypropylene (nanoPP). This novel polypropylene is dyeable with both acid and disperse dyes. The acid dyeability of the nanoPP is due to the ionic attraction between the negatively charged acid dye and the positively charged quaternary ammonium salts in the nanoclay. Van der Waals forces, and perhaps hydrogen bonding, also play important roles in acid dyeing of the nanoPP. For the dyeing with disperse dye, it is proposed that the attraction between the disperse dye and nanoclay is mainly due to the van der Waals forces and hydrogen bonding. This research has shown that the color yield of the nanoPP is influenced by the add-on of nanoclay in the nanoPP. Moreover, the levelness of nanoPP dyeing is dependent on the uniform distribution of the nanoparticles in the polypropylene matrix. Longer homogenizing time generally produced a comparatively level dyeing.