A novel phosphorus-containing lignin-based flame retardant and its application in polyurethane

Fabrication of high transparent, mechanical strong, and flame retardant waterborne polyurethane composites by incorporating phosphorus‐silicon functionalized cellulose nanocrystals

“…As described above, the addition of FCNC filler (3 wt%) could effective in improving the flame retardancy of polymeric composite, the flame retardancy mechanism is shown in Figure 8. When the WPU‐FCNCs composites exposed to flame, the decomposition for FCNC released a few incombustible gas during the combustion, 24 thus diluting the flammable volatiles/oxygen concentration and reducing flame‐propagation. Along with this, the functionalized P‐ and Si‐ containing components of FCNC were thermal‐degraded into a P‐ and Si‐ layers on its surface, thus coordinately forming a strengthened protective carbonaceous layers 42 .…”

“…However, currently known literatures about modified CNC‐based WPU composites rarely focus on the flame retardancy performance. According to the previous literatures, the reinforcing fillers (i.e., modified lignin, 24 chitosan, 25 graphene oxide, 26 and so on) with phosphorus‐ and/or silicon‐containing components can reducing the combustibility of polyurethane materials. The incorporated filler with phosphorus‐silicon components could effectively quench the free radical chain reactions during combustion, and the formed incombustible gases as well as the reinforced carbonaceous protect layers could inhibit the fire propagation 26,27 .…”

Multifunctional lignin-based nanocomposites and nanohybrids

“…The majority of these lignin-based fire-retardant polymers are P-lignin, 423 N-lignin, 424 and PN-lignins. 417,425 There are also works incorporating siloxane, 426 and boron 427 in lignin-based fire retardant materials. Though lignin itself has been found to exhibit intumescent behaviour, 428 mainly chemically modified lignins have been evaluated in intumescent coating systems that swell upon thermal exposure and form a protective carbonaceous char layer.…”

Preparation of shape memory polyurethane/modified cellulose nanocrystals composites with balanced comprehensive performances

“…Briefly, when the SMPU-MCNC composite exposed to a flame, the thermal degradation of MCNC containing nitrogen units could release few noncombustible gases to dilute the flammable volatiles and oxygen concentration during the combustion. 26 Meanwhile, the phosphorus-containing units in MCNC could release POÁ radicals during thermal decomposition (gas-phase), and thus quenching OHÁ and HÁ radicals in the flame and reduce the evaporation of combustible volatiles, leading to a reduction in flame propagation. 23,40 Along with this, the grafted phosphorus-containing units of MCNC could synergistically catalyze to form a phosphorusstrengthened carbonaceous protective layer (solid phase) with SMPU matrix.…”

“…Currently known literatures of the ordinary polyurethane composites containing modified cellulose and lignin possessed good flame retardancy. 25,26…”