Acoustic properties of polyurethane compositions enhanced with multi‐walled carbon nanotubes and silica nanoparticles

Abstract

In this study, in order to enhance acoustic properties of polyurethane (PU) foams multi‐walled carbon nanotubes (MWCNT) and/or silica nanoparticles were added to polyol‐isocyanate composition up to 2 wt%, and acoustic properties of polyurethane foam samples with small amount of carbon nanotubes and silica nanoparticles (spherical and/or amorphous types) were determined in the frequency range from 50 Hz up to 6400 Hz. Acoustic properties, especially absorption coefficient of the produced samples were measured for all the prepared samples and results were investigated to come up with the best polyurethane samples that can be applied for sound absorption application at the desired frequency range. It was found that double combination of carbon nanotubes and silica nanoparticles, especially 0.7 wt% carbon nanotubes and 0.2 wt% spherical silica nanoparticle added polyurethane composition has better sound absorption ratio overall all frequencies levels compared to the other samples. Thus, it is possible to obtain polyurethane nanocomposite with a higher amount of carbon nanotube by weight at the same time enhancing sound absorption properties. Moreover, there is a synergic effect between carbon nanotubes and silica nanoparticles when mixed and added into polyurethane matrix at predetermined levels to get enhanced acoustic response with a higher level of carbon nanotube in polyurethane foam.

Analytical modeling and experimentally optimizing synergistic effect on thermal conductivity enhancement of polyurethane nanocomposites with hybrid carbon nanofillers

“…The isocyanate was finally added to the carbon nanofiller/polyol composition, which was stirred for 20 seconds and then poured into a two‐part wooden mold with a diameter of 180 mm to form free‐rise PU foam (Figure 1). [ 21,22,30 ] Table 3 summarizes the fabricated nanocomposites with MWCNTs, graphene, and their compositions. For hybrid nanocomposites, the ratio of carbon nanotubes and graphene nanoplatelets was varied for each graphene type to investigate their effectiveness in the thermal conductivity of the nanocomposites.…”

“…Before the PU synthesis, used MWCNTs were functionalized with hydrogen peroxide (H 2 O 2 ) to better interconnecting GNPs and formation of 3D structure in the polymer matrix, as reported elsewhere. [21,22,30] Different contents and ratios of MWCNTs and graphene were first mixed with polyol at 200 to 2000 rpm for 5 minutes using overhead stirrer equipment. Subsequently, the combination was ultrasonically dispersed for 5 minutes using ultrasonication and stirred again at 2000 rpm about 5 minutes.…”

“…The isocyanate was finally added to the carbon nanofiller/polyol composition, which was stirred for 20 seconds and then poured into a two-part wooden mold with a diameter of 180 mm to form free-rise PU foam ( Figure 1). [21,22,30] range of 2θ = 10 to 50 . An intense peak at 2θ = 26.4 is obvious for all graphene, in which GNP-L150 and GNP-M150 have a much sharper peak, representing that GNP-L150 and GNP-M150 are more crystalline than MWCNTs and GNP-S750.…”

Graphene type dependence of carbon nanotubes/graphene nanoplatelets polyurethane hybrid nanocomposites: Micromechanical modeling and mechanical properties

“…In the above relations, Vf is the volume fraction of MWCNTs and graphene, which can be calculated based on the density and weight fraction of nanofillers and neat PU [43]. Based on the manufacturer datasheet, the graphene and MWCNTs densities were considered 2250 kg/m 3…”

“…However, their applications are limited because of their poor mechanical properties. Therefore, it seems attractive to modify PUs using nanoparticles to modify their mechanical properties [1][2][3][4][5][6]. In addition, components of PUs (polyol and isocyanate) are in a liquid form, which allow for the simple integration of solid nanofillers.…”