A simple preparation method and characterization of epoxy reinforced microporous phenolic open-cell sound absorbent foam

Herein, the acoustically and thermally insulating epoxy foams were prepared using non‐traditional expandable microspheres. The effect of foaming temperature and microsphere content on the morphology, the mechanical strength, the thermal insulation and acoustical properties of the epoxy foams was investigated in detail. It can be found that the closed pores can be partially opened by adjusting the preparation parameters, which is also accompanied by obvious changes in acoustic and thermal insulation properties. By giving high‐content expandable microspheres above 2 wt%, the epoxy foams exhibit highly thermal insulation, and meanwhile achieving an acceptable mechanical property. The results convince us that such light‐weight epoxy foams will outshine as the promising structural, soundproof and heat‐insulated material in many multifunctional systems, such as buildings, vehicles and aircrafts. POLYM. ENG. SCI., 59:799–806, 2019. © 2018 Society of Plastics Engineers

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“…The density of epoxy foams was geometrically investigated according to ISO 854: 2006 . The results were obtained based on the following equation:

normalρ = \frac{m}{v}

where ρ denotes the apparent density of epoxy foam, m and v are the mass and volume of the foam sample, respectively.…”

Section: Resultsmentioning

confidence: 99%

Acoustically and thermally insulating epoxy foams prepared by non‐traditional expandable microspheres

Bai

Zhang

Bao³

2018

Polymer Engineering & Sci

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“…However, the free phenol content in the system was still lower than that in the pristine phenolic resin. This is because the epoxy bond in SAECD can react with free phenol, which reduces the free phenol content in the system. It could be seen from the figure that the content of free aldehydes gradually increased with the increase of SAECD.…”

Section: Resultsmentioning

confidence: 99%

“…When the content of SAECD reaches 4 wt%, the cells differs in size, and the distribution is relatively unconcentrated compared with that of SPF with 3 wt%. This is because unreacted SAECD causes separated multiphase with irregular dispersion . The irregular cells and large bubbles, are likely responsible for the low mechanical properties of the foam.…”

Section: Resultsmentioning

confidence: 99%

Enhancement of flame‐retardant and mechanical performance of phenolic foam with the incorporation of cardanol‐based siloxane

Yang

et al. 2019

Polymer Composites

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A novel cardanol-based siloxane (SAECD), which has silicon groups and reactive epoxy groups, was synthesized. Its structure was confirmed by Fourier transform infrared spectrometry and 1 H nuclear magnetic resonance. Then, phenolic foams (PFs) modified with different contents of SAECD were prepared. While addition of appropriate amount of SAECD into resin matrix enhances the flexural strength of PFs, incorporation of SAECD into PFs leads to a reduced pulverization ratio. The limiting oxygen index (LOI) increases continuously with the increasing addition of SAECD into PFs. The results of the cone calorimeter test showed that the addition of 3% SAECD could effectively reduce the heat release rate and total heat release of the foam by the condensed phase flame retardant mechanism. The TTI of the modified foam was delayed by 19 s; the PHRR, mean HRR, and THR of the modified foams decreased by 9.10%, 4.11%, and 7.55%, respectively, compared with those of the pristine PF. In addition to the increase in the toughness of the PF, SAECD addition can also improve the flame retardant properties of the PF. K E Y W O R D S ORCID Caiying Bo https://orcid.org/0000-0002-7032-9931 F I G U R E 9 Photographs of char residues of PF and 3% SAECD modified PF [Color figure can be viewed at wileyonlinelibrary.com]

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“…Finally, the arithmetic mean value of five samples was taken as the pulverization rate of the foam. The pulverization rate was determined as the percent of mass loss during the test as following Equation 26 (2):…”

Section: Brittleness Testmentioning

confidence: 99%

“…The flexural properties were characterized by threepoint bending tests according to ISO 1209-1:2004. 26 The dimension of the specimens used for the test was (120 ± 1.2) mm × (25 ± 0.25) mm × (20 ± 0.20) mm (length, width, and thickness, respectively), the constant deformation rate was maintained at 10 mm/min. The tests are continued until specimen failure.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Preparation and properties of nano ZnO toughed phenol–urea‐formaldehyde foam

Wang

Zheng

et al. 2020

J of Applied Polymer Sci

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Urea formaldehyde (UF) and phenol formaldehyde (PF) foam possess outstanding flame-retardant properties, excellent insulation, and low thermal conductivity. These properties make them suitable for thermal insulation in buildings. However, the mechanical properties still need to be improved. In this study, orthogonal test was designed to optimize the level components of PF/UF composite foam first, then nano ZnO was added to the PF/UF composite foam to improve its toughness. The effects of nano ZnO on the morphology, apparent density, pulverization rate, thermal conductivity and thermal degradation property, flame retardancy, and mechanical properties of the ZnO/PF/UF nanocomposite foam were studied. The addition of nano ZnO improved the bending and compressive strength and decreased the pulverization rate of the composite foam significantly. The ZnO/PF/UF nanocomposite foam also presented better flame retardant properties than PF/UF composite foam. The largest oxygen index values of ZnO/PF/UF nanocomposite foam could reach 39.31%, while the thermal conductivity and the maximum rate of weight loss temperature were increased to 0.036 W/(mÁK) and 279 C, respectively. Moreover, ZnO/PF/UF nanocomposite foam showed low apparent density property (0.27 g/cm 3). K E Y W O R D S composites, foams, mechanical properties, nanoparticles, thermosets 1 | INTRODUCTION At present, the thermal insulation materials used in building mainly include organic thermal insulation materials and inorganic thermal insulation materials. Organic insulation material (polymer foam material) is a microporous material made from polymer matrix filled with gas, which presents low density, low water absorption, high porosity, and excellent insulation performance. 1-3 Thus, it is widely used in the construction industry owing to excellent flame retardancy, chemical resistance, environmental friendly, thermal insulation, low price, and low water absorption. Urea formaldehyde (UF) foam and phenol formaldehyde (PF) foam has been extensively promoted as the most suitable alternative for thermal insulation building materials. 4-8 However, UF foam lacks active functional groups, thus, it always presents high brittleness, high pulverization ratio, low strength, and toughness. Meanwhile, PF foam also suffers from some mechanical weaknesses. For these reasons, it is necessary to focus on the improvement of PF/UF composite foam mechanical properties, such as, compressive and bending strength, friability and pulverization rate, while still maintaining their excellent flame retardant properties. In general, the toughness of foams can be improved by two methods: the physical method and the chemical

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A simple preparation method and characterization of epoxy reinforced microporous phenolic open-cell sound absorbent foam

Cited by 25 publications

References 22 publications

Acoustically and thermally insulating epoxy foams prepared by non‐traditional expandable microspheres

Acoustically and thermally insulating epoxy foams prepared by non‐traditional expandable microspheres

Enhancement of flame‐retardant and mechanical performance of phenolic foam with the incorporation of cardanol‐based siloxane

Preparation and properties of nano ZnO toughed phenol–urea‐formaldehyde foam

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