Polybenzoxazine Aerogels for Thermal Protection at Extremely High-Temperature/Cryogenic Conditions

Zhang, Sizhao; Wang, Jing; Lu, Kunming; Xu, Guangyu; Wang, Zhao; Xiao, Yunyun; Ji, Hui Ming; Yang, Zhouyuan; Yang, Yourong; Xiong, Shixian; Li, Zhengquan

doi:10.1016/j.polymer.2022.125424

Cited by 14 publications

(3 citation statements)

References 29 publications

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“…Aerogels are a class of nanoporous solids with low density, high porosities, and high specific surface area . Aerogels have been used in aerospace and electronic applications because of their excellent thermal-insulation performance. − Silica aerogels have been studied most extensively because they exhibit the lowest thermal conductivity among all aerogels; however, their inherent properties including brittleness and hydroscopicity limit their application in aerospace thermal protection. , Some attempts have been made to enhance the compressive strength of silica aerogels such as by reinforcing the silica backbone with a conformal polymer coating .…”

Section: Introductionmentioning

confidence: 99%

Reusable Nanoporous Al₂O₃-Containing Polyimide Aerogels for Thermal Insulation of Aircraft

Zhang,

Wang,

Wang

et al. 2023

ACS Appl. Nano Mater.

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Reusable nanoporous polyimide (PI) aerogels are rather promising for highly efficient thermal insulation of future thermal protection systems demanded in aerospace and domestic applications. However, the development of high-performance PI aerogels is limited by their unsatisfactory high-temperature resistance and poor reusability. Herein, an Al2O3-hybridization strategy toward PI aerogels is demonstrated, and the formed aerogels exhibit a nanoporous structure, unusual reusability, and exceptional high-temperature resistance. Furthermore, the aerogels retain their high-level properties such as the very small changing rates of mass (≤0.3%), shrinkage (≤2.53%), thermal conductivity (≤3%), and bulk density (near-zero difference) even after five cycles of high-temperature assessment (250 °C for 2400 s). The conventional huge heat-induced shrinkage of PI aerogels could be substantially restrained even bearing a high-temperature environment, realizing near-zero thermally insulating degradation, which has an outstanding practical application value. The high-temperature resistance of the aerogel is greatly improved by the Al–O network constructed inside the PI aerogels, and this resistance is retained even after multiple cycles under harsh conditions, ultimately affording superior reusability to PI aerogels for the first time. The high-temperature resistance and ultralow heat-induced shrinkage properties of aerogels, as well as their reusability, make them favorable candidates as thermal protection materials for the future development of aircraft and military.

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Section: Introductionmentioning

confidence: 99%

Reusable Nanoporous Al₂O₃-Containing Polyimide Aerogels for Thermal Insulation of Aircraft

Zhang,

Wang,

Wang

et al. 2023

ACS Appl. Nano Mater.

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“…However, to be used as electronic materials, the relatively high polarity, high water uptake, low thermal resistance, and high dielectric constant is not ideal 28 . Consequently, the epoxy resin based electronic materials are usually considered as low end product 29 . It is well known that epoxy resins cannot be cured without curing agents, 30 and the properties of the final cured resins are highly dependent on the curing agents.…”

Section: Introductionmentioning

confidence: 99%

“…28 Consequently, the epoxy resin based electronic materials are usually considered as low end product. 29 It is well known that epoxy resins cannot be cured without curing agents, 30 and the properties of the final cured resins are highly dependent on the curing agents. Importantly, the active functional species such as phenolic hydroxyls and amino groups could play as curing agents for epoxy resins and copolymerization between benzoxazine and epoxy resin could be achieved.…”

Section: Introductionmentioning

confidence: 99%

Optimizing the dielectric and mechanical properties of melamine based‐benzoxazine resin by copolymerizing with epoxy resin

Fan

Zhang

et al. 2023

J of Applied Polymer Sci

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Benzoxazine resins are suffering from high curing temperature, low crosslinking density, and poor toughness, which hampers their broad applications. The introduction of melamine during synthesis has been shown useful in improving these properties, but the dielectric property was deteriorated heavily. Epoxy resins show higher crosslinking density and better toughness but the thermal properties are relatively poor. Herein, the melamine based‐benzoxazine MBF was copolymerized with epoxy resin E51 in this work in order to improve the dielectric properties. The curing reactivity, polymerization mechanism and the comprehensive properties such as thermal, dielectric and mechanical properties were systematically verified. It is found that the abundant active functional groups such as amino and phenolic groups in MBF could catalyze and copolymerize with E51 and form uniform copolymers poly(MBF‐E) at various proportions. With the increasing of epoxy resins, more polar amino groups was consumed, thus the polarity and the water absorption of the copolymers decreased. Additionally, the dielectric constant decreased from 3.67 for poly(MBF) to 2.94 for poly(MBF‐60E). Meanwhile, the highest increasement of tensile strength and elongation at break value reached 130% and 70%, respectively, which may be caused by the higher crosslinking density and more flexible ether bond formed.

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Ultralight and Anisotropic Heterocyclic Para-aramid Nanofiber/Reduced Graphene Oxide Composite Aerogel for Efficient Thermal Insulation and Flame Retardancy

Wu,

Shang,

et al. 2024

Chin J Polym Sci

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Polybenzoxazine Aerogels for Thermal Protection at Extremely High-Temperature/Cryogenic Conditions

Cited by 14 publications

References 29 publications

Reusable Nanoporous Al₂O₃-Containing Polyimide Aerogels for Thermal Insulation of Aircraft

Reusable Nanoporous Al₂O₃-Containing Polyimide Aerogels for Thermal Insulation of Aircraft

Optimizing the dielectric and mechanical properties of melamine based‐benzoxazine resin by copolymerizing with epoxy resin

Ultralight and Anisotropic Heterocyclic Para-aramid Nanofiber/Reduced Graphene Oxide Composite Aerogel for Efficient Thermal Insulation and Flame Retardancy

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Polybenzoxazine Aerogels for Thermal Protection at Extremely High-Temperature/Cryogenic Conditions

Cited by 14 publications

References 29 publications

Reusable Nanoporous Al2O3-Containing Polyimide Aerogels for Thermal Insulation of Aircraft

Reusable Nanoporous Al2O3-Containing Polyimide Aerogels for Thermal Insulation of Aircraft

Optimizing the dielectric and mechanical properties of melamine based‐benzoxazine resin by copolymerizing with epoxy resin

Ultralight and Anisotropic Heterocyclic Para-aramid Nanofiber/Reduced Graphene Oxide Composite Aerogel for Efficient Thermal Insulation and Flame Retardancy

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Reusable Nanoporous Al₂O₃-Containing Polyimide Aerogels for Thermal Insulation of Aircraft

Reusable Nanoporous Al₂O₃-Containing Polyimide Aerogels for Thermal Insulation of Aircraft