A double-decker silsesquioxane of norbornene and performance of crosslinking reactive modified EPDM ablation resistance composites

Ma, Xutao; Ji, Tiezheng; Zhang, Junan; Shen, Shuai; Wang, Shumeng; Wang, Jian; Hou, Xiao; Yang, Shishan; Ma, Xiaoyan

doi:10.1016/j.compositesa.2022.107370

Cited by 12 publications

(19 citation statements)

References 30 publications

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“…72 Through the hydrosilylation of dihydro DDSQ with 4-acetoxystyrene and the subsequent hydrolysis of acetoxyl groups, diphenolic hydroxyl DDSQ would be achieved. 73 Alternatively, dihydro DDSQ can reactwith 4-bromostyrene, 74 allyl glycidyl ether, 75 nadic anhydride, 76 dienes (e.g., 1,5-hexadiene and 1,9-decadiene) 77 to obtain dibromobenzene, diepoxy dianhydride and dialkenyl DDSQ, respectively. Except for methyldichlorosilane, other silanes also can be used for silylation reaction with DDSQ-4OX (X = Na or H) to produce DDSQ macromers.…”

Section: T 10 Type Asymmetrical Silsesquioxane Routementioning

confidence: 99%

“…This is a DDSQ-based approach, in which the selective protection S C H E M E 5 Synthesis of typical DDSQ macromers resulting from dihydro DDSQ. [71][72][73][74][75][76][77][78][79][80] Reprinted with permission of American Chemical Society, Elsevier, Royal Society of Chemistry, and John & Wiley Sons. reaction and isolation of DDSQ tetrasilanol (i.e., DDSQ-4OH) (Scheme 7) are involved.…”

Section: T 10 Type Asymmetrical Silsequioxane Routementioning

confidence: 99%

“…Different from mono-and octa-functional POSS, difunctional POSS can be inserted into polymer backbones through stepgrowth polymerizations, thereby altering the structure of polymer backbone. Typically, the step-growth polymerizations can be performed from diamine POSS and dianhydride, [74][75][76] dihydroxyl POSS and diisocyanate, [79][80][81][82][83] diepoxy POSS and diphenol 42 to generate hybrid polyimide (PI), polyurethane (PU), poly(hydroxyether of bisphenol A) (PH), respectively. These copolymers will be discussed in the next part.…”

Section: Step-growth Polymerizationmentioning

confidence: 99%

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Well‐defined difunctional POSS macromers and related organic–inorganic polymers: Precision synthesis, structure and properties

Li,

Wang,

Zheng

2023

Journal of Polymer Science

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Polyhedral oligomeric silsesquioxanes (POSS) are a class of well‐defined organic–inorganic stereo molecules comprising inorganic SiOSi cores and peripheral organic moieties. Since they were first reported in 1946 by Scott et al., there have been a great number of investigations on the use of POSS macromers as the building blocks to access the organic–inorganic composites with polymers. In most of cases, monofunctional POSS macromers are employed and the linear hybrid polymers are obtained. Under this circumstance, POSS cages act as the side or end groups whereas the main chains of the polymers remain unchanged. Occasionally, octafunctional POSS macromers are involved, resulting in the generation of crosslinked (or network‐like) hybrids. Recently, well‐defined difunctional POSS macromers have increasingly provoked a considerable attention of investigators. From the synthetic methodology of POSS macromers to the approaches to introduce them into polymers, difunctional POSS macromers have the features quite different from mono‐ (or octa‐) functional POSS. More importantly, the related organic–inorganic hybrids possess the different morphologies and properties. In the past years, there has been a rapid increase in the number of literatures on the studies on well‐defined difunctional POSS and the related organic–inorganic hybrids. Nonetheless, the related review is lacking. In this contribution, we would summarize the recent progress in this regard, from the synthesis of POSS macromers, the approaches of introducing the POSS macromers into polymers to the correlation of morphologies with properties of the organic–inorganic hybrids. In addition, perspectives and challenges for the further advancement are envisaged and discussed.

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Section: T 10 Type Asymmetrical Silsesquioxane Routementioning

confidence: 99%

Section: T 10 Type Asymmetrical Silsequioxane Routementioning

confidence: 99%

Section: Step-growth Polymerizationmentioning

confidence: 99%

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Well‐defined difunctional POSS macromers and related organic–inorganic polymers: Precision synthesis, structure and properties

Li,

Wang,

Zheng

2023

Journal of Polymer Science

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“…Aramid fiber (AF), which has low density, high strength, high modulus, and high-temperature resistance, 20,21 forms a fibrous carbon structure at high temperatures, 22 and the fiber backbone structure can stabilize the char layer. 23 Basalt fiber (BF) is a brown and metallic shiny fiber drawn from the natural basalt, 24 and it is an ideal alternative to carcinogenic asbestos fiber in ablation field due to the existence of oxides such as SiO 2 , Al 2 O 3 , Fe 2 O 3, and TiO 2. [25][26][27] BF is characterized by high strength and high modulus, electrical insulation, oxidation, and corrosion resistance, as well as high-temperature resistance.…”

Section: Introductionmentioning

confidence: 99%

Improving the ablative performance of epoxy‐modified vinyl silicone rubber composites by incorporating different types of reinforcing fibers

Zhang,

Huang,

Xing

et al. 2024

Polymer Composites

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In this study, ablative resistance of single fiber‐ and hybrid fiber‐reinforced epoxy‐modified vinyl silicone rubber (EMVSR) composites was systematically studied. Three types of fibers, namely aramid fiber (AF), basalt fiber (BF), and carbon fiber (CF), were employed as the reinforcements. The results indicated that the incorporation of fiber reinforcements effectively suppressed the expansion and strengthened the char layer. Besides, the quality of char layer was quite different when different types of fibers were used. The char layer of AF‐modified samples had more surface defects, BF‐modified samples were brittle, and CF‐filled samples were dense and flat. The use of hybrid AF/BF fibers improved the ablation and anti‐erosion performance of EMVSR. Meanwhile, the thermal insulation performance was enhanced because the back‐face temperature was the lowest with the addition of 1 phr AF and 5 phr CF. The above results indicated that the ablation and anti‐erosion resistance and the quality of char layer as well as the thermal insulation behavior of EMVSR were significantly improved by incorporating fibrillar fillers, which demonstrate practical applications as flexible anti‐ablation materials for thermal protection systems.Highlights Epoxy‐modified vinyl silicone rubber was used for preparing ablative composites. The effect of adding different fibers on the ablation properties was studied. The presence of single fibers improved the strength of char layer. The use of hybrid fibers was found effective in enhancing the ablative properties. The intrinsic property and entanglement of fibers affected the ablative properties.

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“…During the application of ablative materials and thermal protection systems (TPS), 1 it is necessary to consider the functional filler‐containing systems 2 and different heat requirements 3,4 to ensure the thermal insulation performance 5 . The char layer formed during the ablation process mainly comes from the vitrified layer 6 .…”

Section: Introductionmentioning

confidence: 99%

Improving the transient thermal response and ablation properties of epoxy‐modified silicone rubber composites by adding fluxing agent

Zhang,

Zhou,

Liang

et al. 2023

J of Applied Polymer Sci

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In this work, transient thermal response and ablation behavior of liquid silicone rubber composites containing fluxing/ceramic forming fillers were investigated under different heat flows using an oxyacetylene flame. The results indicated that the introduction of zinc borate (ZB) and aluminum oxide (Al2O3) effectively reduced the temperature at various depths of the samples, and they improved the thermal insulation properties and lowered pyrolysis rates. The above finding was attributed to the heat absorption arising from water release and melt filling as well as the vitrified reaction of solid melt due to the decomposition of ZB. Besides, the melting and exfoliation of Al2O3 and the formation of aluminum silicate (Al2SiO5) caused heat absorption effect. Additionally, the mass ablation rates and line ablation rates increased with rising heat flows coupling with a decrease of compressive strength of the char layers. In a nutshell, the effect of adding ZB/Al2O3 on the thermal insulation behavior of epoxy‐modified vinyl silicone rubber (EMVSR) composites under different heat flows was elucidtaed. This work served as a reference for the design and preparation of flexible ablative materials for thermal protection applications.

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A double-decker silsesquioxane of norbornene and performance of crosslinking reactive modified EPDM ablation resistance composites

Cited by 12 publications

References 30 publications

Well‐defined difunctional POSS macromers and related organic–inorganic polymers: Precision synthesis, structure and properties

Well‐defined difunctional POSS macromers and related organic–inorganic polymers: Precision synthesis, structure and properties

Improving the ablative performance of epoxy‐modified vinyl silicone rubber composites by incorporating different types of reinforcing fibers

Improving the transient thermal response and ablation properties of epoxy‐modified silicone rubber composites by adding fluxing agent

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