Tough and Strong Waterborne Polyurethane Network Combined with Sub-Nanoscaled Calcium Phosphate Oligomers for Protective Coating

The optimal design of high wear-resistance and durability of coatings using organic-inorganic interpenetrating networks has been a long-term goal of researchers. Although some progress has been made in the modification of waterborne polyurethanes (WPU), there are still significant challenges in fabricating more durable polyurethane-based protective coatings from the perspective of structural design at a molecular level. Here, a sub-nanoscaled (<1 nm) inorganic calcium phosphate oligomer (CPO) is used to carry out organic-inorganic hybrid cross-linking in a WPU network and precisely regulate the structure of the macromolecular network at the molecular level. The herein-produced CPO-WPU hybrid coating shows excellent wear resistance and water resistance. Taber abrasion tests demonstrate that the CPO-WPU coating can be capable of 15 500 turns at a load of 750 g, 2.2 times that of pure WPU coating, and the water-resistance of CPO-WPU coating is significantly improved compared with WPU coating due to its well-integrated organic-inorganic network. Overall, the CPO-WPU coating material significantly improves the mechanical strength, wear-resistance, and water-resistance, compared with the original WPU coating and other modified polyurethane. This hybrid coating can provide a potential application in paper-making, textiles, and furniture due to its unique organic-inorganic network, low cost, and green process.

Automated summary

The optimal design of organic-inorganic interpenetrating networks in CPO-WPU hybrid coating significantly improves the wear and water resistance of polyurethane protective coatings. The production process is green and cost-effective, making it suitable for applications in paper-making, textiles, and furniture.