Comparison of finishing application for aliphatic polyurethane dispersions and polyurethane/polyacrylate composite emulsions

Aliphatic and aromatic cationic aqueous polyurethane (PU-1, PU-2), aliphatic anionic aqueous polyurethanes (PU-3, PU-4) were prepared with polyether glycol, polyether polyol, toluene diisocyanate and isophorone diisocyanate as raw materials. The core-shell polyurethane/polyacrylate composite emulsions (PUA-5, PUA-6) as well as interpenetrating PUA composite emulsions (PUA-7，PUA-8) were prepared by seeded emulsion polymerization, the aliphatic anionic aqueous PU dispersions were used as seed particles, glycidyl methacrylate was used as the bridge of core and shell in second stage polymerization. A study using different finishing applications for pigskin garment leather was carried out with the aliphatic anionic PU dispersion, the core-shell and interpenetrating structure PUA hybrid emulsions as film forming agents. The wet rub fastness, solvent resistance, flex resistance, adhesive fastness of the coating in finished leather were measured respectively. The results are as follows: (1) the anionic PU dispersions, the core-shell and interpenetrating PUA composite emulsions showed good film forming, good covering grain damage and mending properties, and strong adhesive force to leather. The finished leathers were soft, flat, smooth, non-sticky and their grain patterns were clear; (2) The interpenetrating PUA is better than core-shell PUA and the core-sell PUA is better than the PU dispersion at wet rub fastness, solvent resistance, adhesive resistance. Both PU dispersion and core-shell PUA were better than the interpenetrating PUA at flex resistance by comparison.