Influence of filler surface characteristics on morphological, physical, acoustic properties of polyurethane composite foams filled with inorganic fillers

Fire Suppression and Thermal Behavior of Biobased Rigid Polyurethane Foam Filled with Biomass Incineration Waste Ash

“…In this case, WA particles purposefully interact with the WAPU foam matrix ( Figure 1) and affect apparent density in their own way, i.e., 10 wt.% of WA in WAPU-10 foam averagely increase apparent density by 22% compared to that of a neat PU, whereas 30 wt.% and 50 wt.% of WA increase apparent density by 34% and 49%, respectively. According to the work in [21,22,[35][36][37], organic and inorganic fillers increase dynamic viscosity of liquid mixtures which hinders the blowing efficiency of the foams. Energy dispersion spectroscopy (EDS) results were determined using scanning electron microscope (SEM) QUANTA 250 ("FEI Company", Hillsboro, OR, USA) with EDS analyzer and INCA analytical system.…”

“…Some of the waste-based and filler-type additives consist of inorganic particles that can act as a flame spread barrier and improve fire resistance characteristics, such as heat release rate, as well as shift towards higher thermal degradation temperature [20]. However, such inorganic waste-based and filler type additives can be used in rather low amounts, because they increase viscosity, cause cell rupture, and deteriorate performance characteristics [21,22]. Researchers [23] observed that the addition of up to 40 wt.% of basalt waste reduces the compressive strength of PU composites and worsens their dimensional stability, whereas others [24] tested feldspar and kaolinite clay and showed that even 10 wt.% reduces mechanical performance of the resultant PU foams.…”

Mechanical properties, thermal stability, sound absorption, and flame retardancy of rigid PU foam composites containing a fire‐retarding agent: Effect of magnesium hydroxide and aluminum hydroxide

“…Increasing the microstructural slippage at the interfaces between the polymer matrix and filler surfaces was also proven to improve the sound absorption coefficient. 38 NRC was plotted in Figure 6C. In analyzing the sound absorption efficiency, the NRC (arithmetic mean of absorption coefficients at 250, 500, 1000, and 2000 Hz) is generally used for interpretation of the acoustic properties.…”

Sound Absorption Properties of Polyurethane Foams Derived From Waste Cooking Oil Incorporated With Waste Wood Fiber Filler

“…The methods involved in wave dissipation process are firstly, the sound absorption is increased by damping motions of the foams with the Red Meranti fillers, as explained with the effects of movements by Red Meranti fillers when polymer foam recovers from the deformation caused by the sound energy [20]. While, second method is the change in wave penetration pathways whereby the sound absorption was increased due to the pore structures in the foam matrix [7].…”

“…When sound waves hit a surface they can be reflected, absorbed or transmitted [20]. Sound wave in the form of heat energy is produced due to the friction between air flowing in and or out of the cells [21,7].…”