Effect of nano-montmorillonite as cell opener on cell morphology and resilient performance of slow-resilience flexible polyurethane foams

In this paper, polypropylene glycol Y-1900, unmodified nano-montmorillonite (MMT) and organically modified nano-montmorillonite (OMMT) serving as cell openers are introduced into slow-resilience flexible polyurethane foams (FPUFs), aiming at investigating the effects of them on cell morphology and the relationships between cell structure, nano-montmorillonite types and resilient performance of slow-resilience FPUFs. Experimental results indicate that OMMT can sever as an excellent alternative for conventional cell openers. The ability of nano-montmorillonite to open cells mainly depends on their surface property. Both MMT and OMMT are exfoliated in foaming process and play a significant role in cell diameter for nucleating function. The resilient performance of foams is closely related to open cell content and polyurethane matrix nature, due to that the friction effect of nano-montmorillonite and the deformation of open cells will lead to large energy dissipation. The mechanical properties (tensile strength, elongation at break and compression set) are related to cell structure and nano-montmorillonite. The addition of nano-montmorillonite especially organically modified nano-montmorillonite is an effective method to improve resilient performance and mechanical strength. However, this improvement is at the expense of impairing toughness of foams.