Mesophase pitch modified silicone rubber coatings with fence-like ceramic layer structures and excellent ablation resistance performance

Liu, Zhuodong; Huang, Yisen; Yan, Liwei; Yang, Chen; Liang, Mei; Zou, Huawei

doi:10.1016/j.porgcoat.2022.106773

Cited by 12 publications

(4 citation statements)

References 14 publications

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“…Liquid crystals such as mesophase pitch (MP) can form graphitic carbon with a higher degree of order during their liquid carbonization process and are also used in ablation-resistant materials. In the previous study, [20] we introduced MP into the silicone rubber composites, and found that MP effectively increased the content of graphitic carbon in the ceramic layers and enhanced the strength of the ceramic layers. However, in order to further increase the graphitic carbon content of the ceramic layer, more efficient methods need to be found.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Graphitized Silicone Rubber Coatings with Highly Graphitized Ceramic Layer and Superior Ablation Resistance

Chen

Liu

Huang

et al. 2022

Macro Materials & Eng

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The strength of the ceramic layer formed during ablation of the silicone rubber composite is closely related to its resistance to ablation. Increasing the content of graphitic carbon in the ceramic layer plays a key role in enhancing the strength of ceramic layer. In this study, series of catalytically graphitized mesophase pitch‐modified silicone rubber composites with excellent ablation performance are prepared. And the average linear ablation rate of the composite is reduced to a maximum of 0.046 mm s‐1, which is 44.0% lower than that of the sample without catalyst named 5MP. XRD characterization proves that the addition of transition metal catalysts increases the content of graphitic carbon in the ceramic layers after ablation. The strength of ceramic layer of the 0.13Fe2O3 reached 12.09 MPa, which is 60.3% higher than that of the 5MP. The transition metal catalyst effectively increases the content of graphitic carbon in the ceramic layers, and the strengths of the ceramic layers are significantly improved, thereby greatly improving the ablation performance of the composites.

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Section: Introductionmentioning

confidence: 99%

Catalytic Graphitized Silicone Rubber Coatings with Highly Graphitized Ceramic Layer and Superior Ablation Resistance

Chen

Liu

Huang

et al. 2022

Macro Materials & Eng

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“…1−3 The demand and quality requirements for mesophase pitch as a carbon material precursor are constantly increasing with the rapid development of the carbon material production industry. 4,5 Mesophase molecules are highly condensed polycyclic aromatic molecules that can be produced from nonvolatile residues of pitch. 6,7 Currently, the byproducts of petroleum and coal chemical are the main raw materials for preparing mesophase pitches, of which the influence on the properties of mesophase pitch is the focus of research.…”

Section: Introductionmentioning

confidence: 99%

“…High-performance carbon materials and their composites are widely used as structural and semiconducting materials in fields such as chemical instrumentation, electrochemistry, nuclear energy, and mechanical engineering. − The demand and quality requirements for mesophase pitch as a carbon material precursor are constantly increasing with the rapid development of the carbon material production industry. , Mesophase molecules are highly condensed polycyclic aromatic molecules that can be produced from nonvolatile residues of pitch. , …”

Section: Introductionmentioning

confidence: 99%

Correlation of Mesophase Properties with Molecular Structures of Pitches from Different Sources

Qi,

Huang,

Baker

et al. 2024

Energy Fuels

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In this paper, the molecular structures of vacuum residue (VR), coal liquefaction pitch (CLP), and coal tar pitch (CTP) are presented in detail, in order to explore their connection with mesophase properties. It is found that the H/C atom ratio of VR is as high as 1.32 because of abundant aliphatic structures. Its average aromatic ring number (R A ) is only 3.88, and some of its internal aromatic rings are connected by bridged bonds. The mesophase pitch from VR (MP-VR) has a low mesophase content of 28.28−40.7% and is mostly of fiber texture. CTP has a degree of aromaticity (f a ) of 0.90 and an R A of 10.65. The polycyclic aromatic molecule has only a few alkyl substituents at the periphery, resulting in a low H/C atom ratio of 0.56. The mesophase pitch from CTP (MP-CTP) has a mesophase content of 31.5−53.9% and has a distinct mosaic texture. CLP has the largest average molecular structure unit size, with an R A of 12.33 and a large degree of condensation. It contained certain cycloalkane structure and methyl substituents. The mesophase pitch from CLP (MP-CLP) has a mesophase content of 43.3−54.4% and contains abundant fiber and flaky textures. The regular and compact lamellar arrangement of planar aromatic macromolecules gives MP-CLP better graphitization properties, thermal stability, and rheological properties than MP-VR and MP-CTP.

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“…Conventionally, flexible ablative materials are prepared using nitrile rubber (NBR) [ 13 ], EPDM rubber [ 14 ], silicone rubber [ 15 ], and polyphosphazene [ 16 ] as the host matrices. Among these materials, silicone rubber is an organic-inorganic elastomeric polymer that exhibits the advantages of high elasticity, corrosion resistance, and non-toxicity.…”

Section: Introductionmentioning

confidence: 99%

Improving the Ablation Properties of Liquid Silicone Rubber Composites by Incorporating Hexaphenoxycyclotriphosphonitrile

et al. 2023

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The ablative properties of epoxy-modified vinyl silicone rubber (EMVSR) composites containing hexaphenoxycyclotriphosphonitrile (HPCTP) have been systematically studied. The strength of the ablation char layer was greatly enhanced with the addition of HPCTP, which induced the formation of a more complete, denser, and thicker char during oxyacetylene ablation tests. Moreover, the HPCTP-containing EMVSR composites demonstrated lower thermal conductivity and pyrolysis rate when compared with those without HPTCP. At the same time, the thermal insulation properties of HPCTP-filled composites were improved under low heat flow ablation scenarios. The reduction of graphitic carbon content, the formation of phosphate-like crystals as well as the increase of SiC content contributed to strengthening the char layer, which was critical for improving the ablation properties. The optimum char layer strength and thermal insulation properties were achieved when the content of HPCTP was 15 phr, whereas an optimum ablation resistance was achieved at 25 phr HPCTP. This suggests that HPCTP-modified EMVSR composites can be used for thermal protection purposes, especially in the fields of aerospace and aeronautics.

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Mesophase pitch modified silicone rubber coatings with fence-like ceramic layer structures and excellent ablation resistance performance

Cited by 12 publications

References 14 publications

Catalytic Graphitized Silicone Rubber Coatings with Highly Graphitized Ceramic Layer and Superior Ablation Resistance

Catalytic Graphitized Silicone Rubber Coatings with Highly Graphitized Ceramic Layer and Superior Ablation Resistance

Correlation of Mesophase Properties with Molecular Structures of Pitches from Different Sources

Improving the Ablation Properties of Liquid Silicone Rubber Composites by Incorporating Hexaphenoxycyclotriphosphonitrile

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