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

Abstract

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 nanomontmorillonite 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 nanomontmorillonite 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.

Preparation of microcellular thermoplastic polyurethane (TPU) foam and its tensile property

“…Figure a shows the expansion ratio of TPU foams as function of foaming temperature. Obviously, the TPU with a higher hard segment content generates more crystalline region, higher viscosity and higher hardness, and the corresponding expansion ratio is restricted . The TPU‐36 has the highest hard segment content generating the highest restriction for the foaming process, the TPU‐32 is next, and the TPU‐26 is the weakest one.…”

Preparation of open cell rigid polyurethane foams and modified with organo-kaolin

“…Khakhar and co-workers 10,11 reported the use of modified montmorillonite clays as cell opener in rigid and flexible polyurethane foams. Zou et al 12 discussed the effect of nano-montmorillonite as cell opener on cell morphology and resilient performance of slow-resilience flexible polyurethane foams. It could be concluded from these studies that nano-montmorillonite had an effect on the cell opening in the foaming process of polyurethane foams.…”

Effects of Isosorbide Incorporation into Flexible Polyurethane Foams: Reversible Urethane Linkages and Antioxidant Activity

“…On the other hand, further increase in ISB content led to an increase in the storage modulus and T g again, resulting from the increased stiffness by the addition of ISB with rigid bicyclic ring. The peak value and width of the tan δ curves is another meaningful indicator of resilient performance of FPUFs [25,61]. As shown in Figure 5d, the tan δ values of the ISB-containing FPUFs were higher compared with the PUF-I0 at room temperature; therefore, a decreased resilience can be expected for the ISB-containing FPUFs.…”

“…Cell opening is typically induced through a combination of internal and external parameters. Internal parameters include the viscosity of the liquid resin [14,15], urea precipitation [16,17], catalyst balance [13,18,19], the effect of surfactant on bubble nucleation and stability [20,21], and the addition of fillers or additives to facilitate cell opening [22,23,24,25]. External parameters enable cell opening after foaming through physical or chemical treatment, such as crushing and reticulation [1,24,26,27,28].…”