Phenolic Material Research Articles

Phenolic resin-based nanoflower porous carbon synthesized by self-assembly of MgO hydrolysis for boosting supercapacitor performance

Although electrode materials with flower-like structures have showing promising achievement for battery energy storage for stable structure and rich specific surface area, there are still some challenges in precisely controlling their microstructure. Inspired by the hydrolysis and self-assembly of MgO into petal-like magnesium hydroxide crystals under alkaline critical micelle conditions, we have proposed to synthesize a unique phenolic resin with a 3D flower-like structure as a carbon precursor. After a series of treatments, the optimal sample consists of nanosheets (thickness ≈27 nm) extending in all directions from the core, with a porous structure, significant specific surface area of 2028 m2/g and pore volume of 1.79 m3/g. Electrochemical experiments confirmed that the sample exhibits satisfactory electrochemical performance as the electrode of supercapacitor. It shows an amazing unique capacitance of 320.1 F/g, and the charge–discharge capacity retention rate exceeds 94.6 % after 5000 cycles. Moreover, a high energy density of 9.44 Wh/kg at 126 W/kg is shown for the symmetrical supercapacitors. We believe that the 3D flower-like morphology formed by the unique lamellar structure can provide more active sites, promote ion transports and increase the stability of structure. These findings suggest a new strategy to control the morphology of phenolic resin-based carbon materials.

Investigation on thermal conductivities of plain-woven carbon/phenolic and silica/phenolic composites at high temperature: Theoretical prediction and experiment

Phenolic resin-based ablation materials have found widespread applications in the aerospace industry. The prediction of their thermal conductivity is of paramount importance for the optimization and evaluation for thermal protection systems. However, there is rarely reported thermal conductivity performance of phenolic composites during ablation processes. Therefore, this investigation theoretically predicts the dynamic response of thermal conductivity at high temperatures for plain-woven carbon/phenolic and high silica/phenolic composites. By combining the progressive cubic ablation model with existing composite material property formulas, a multiscale prediction model for effective thermal conductivity is developed. The thermal performance of the resin matrix, reinforcing fibers, yarns, and overall fabric composites is calculated. Additionally, mesoscale representative volume elements are implemented to investigate the overall heat transfer characteristics of carbon/phenolic and high-silica/phenolic composites, including temperature and heat flux distributions. Moreover, both composites thermal conductivities are measured in the range from 298 K to 473 K. The proposed prediction model demonstrates good reliability, with average deviations of 3.76 % and 7.36 % compared to finite element analysis results and experimental data, respectively.

Tribological behaviors and wettability evolution of phenolic resin-impregnated graphite materials under water immersion condition

This study investigated the tribological behaviors of two phenolic resin-impregnated graphite samples and one non-impregnated sample under dry and water immersion using a reciprocating testing device. The frictional configuration involved a steel hemisphere sliding against the surface of the graphite samples. The influence of water immersion time before each formal test on friction coefficients was discussed. The wettability evolution during the test processes and the difference in porosity, which could significantly affect water infiltrating into the sample matrix and frictional interfaces, were associated with the variation in tribological behaviors. The worn surface morphology and element analysis results indicated that the shallow valleys and pores on the surface of graphite were gradually filled by wear debris from both the graphite samples and the harder counterpart. Based on these experimental results, a tribological mechanism of the phenolic resin-impregnated graphite materials under water immersion was developed.

Common incidents and prevention of urban water supply pipeline accidents

With rapid urbanization, urban water supply pipeline accidents have become increasingly prevalent. Understanding their common occurrences and prevention strategies is crucial for ensuring water safety. This study aims to explore the underlying causes of such incidents, ranging from ageing infrastructure to design flaws and construction issues. By analyzing existing preventive measures and international best practices, this research seeks to contribute to the development of effective strategies for mitigating urban water supply pipeline accidents. This thesis focuses on urban water supply pipeline accidents, addressing both common incidents and preventive measures. It begins by highlighting the unique challenges of fires in high-rise buildings, including their rapid spread and the difficulties in evacuating occupants. The paper then emphasizes the importance of innovative fire-resistant materials, classifying them into various types such as phenolic, sprayed, calcium silicate, and lightweight composite materials. Each type is explored in detail, discussing their properties and potential applications. Finally, the paper outlines the practical use of these materials in fire engineering, emphasizing their role in enhancing the safety and resilience of urban infrastructure. Overall, this thesis contributes valuable insights to understanding and mitigating the risks associated with urban water supply pipeline accidents, promoting disaster prevention and management efforts.

The Effect of Different Extraction Conditions on the Physicochemical Properties of Novel High Methoxyl Pectin-like Polysaccharides from Green Bell Pepper (GBP)

Green peppers are massively produced all over the world; however, substantial quantities of peppers are wasted. Functional polysaccharides can be produced from pepper waste. A conventional acid extraction method was used to obtain pectin-like materials from green bell pepper (GBP). A 23 experimental design (two-level factorials with three factors: temperature, pH, and time) was used to study the relationship between the extraction conditions and the measured physicochemical properties. The extracted polysaccharides were further analysed regarding their physicochemical and functional properties. The yields were in the range of (11.6–20.7%) and the highest yield value was extracted at pH 1. The polysaccharides were classified as “pectin-like”, as the galacturonic acid content was lower than 65%. Glucose and galactose were the major neutral sugars, and their relative amounts were dependent on the extraction conditions. The degree of esterification (DE) of the pectin-like extracts was greater than 50% and they were therefore classified as high methoxyl regardless of the extraction conditions. Also, important levels of phenolic materials (32.3–52.9 mg GAE/g) and proteins (1.5–5.4%) were present in the extract and their amounts varied depending on the extraction conditions. The green bell pepper polysaccharides demonstrated antioxidant and emulsifying activities and could also be used adequately to stabilise oil/water emulsion systems. This finding shows that green bell pepper could be used as an alternative source of antioxidants and an emulsifier/stabilising agent, and furthermore, the extraction conditions could be fine-tunned to produce polysaccharides with the desired quality depending on their application.

Applying fluorescence spectroscopy coupled with Gaussian band fitting to reveal dynamic variation process of humus fractions from riparian soils along an urbanized river

Humus, an important fraction of soil organic matter, play an environmental role on nutrients, organic and inorganic pollutants in riparian zones of urbanized rivers. In this study, dynamic variation process of humus fractions from riparian soils was revealed along Puhe River. Composite soil samples of four depths were collected from four land-uses, i.e., eco-conservation area (ECA), industrial area (INA), urban/town area (UTA), rural/agricultural area (RAA). Based on synchronous fluorescence spectra coupled with Gaussian band fitting, fulvic/humic acid predominantly contained tyrosine-like (TYLF), tryptophan-like (TRLF), microbial-like (MLF), fulvic-like (FLF) and humic-like (HLF) substances within each soil profile. TRLF, MLF and FLF (89.43–90.30 %) are the representative components in fulvic-acid, while MLF and HLF (52.81–59.97 %) in humic-acid. Phenolic, carboxylic and humified materials were present in both humus. According to 2-dimensitonal correlation spectroscopy and canonical correlation analysis, fulvic/humic acid within the ECA soil profile could be mainly derived from the degradations of terrestrial plant metabolites and residuals. Within the INA, fulvic-acid could be associated with treated/untreated wastewater, which entered the river and flew into the riparian during high flow period; whereas humic-acid could be relative to the terrestrials. Fulvic-acid had the same source as humic-acid in the UTA, which might be concerned with scattered domestic sewage and livestock wastewater, rather than the fluvial water. Furthermore, the source of fulvic/humic acid in the RAA was the crop metabolites and residuals, apart from the livestock wastewater. Noticeably, the variations of humus fractions in the ECA and RAA roughly occurred in 0–60 cm, while approximately in 20–80 cm in the INA and UTA. This proved that humus fractions in the former were referred to the plant/crop residuals, whereas humus fractions in the latter were those the terrestrials and fluvial water. This study could provide a key support for the construction and restoration of the urbanized riparian zone.

Cost Analysis and Method Comparison on High-Rise Building Column Formworks by Three Formwork Methods

The purpose of this study was to determine how much cost would be incurred and to analyse the difference in price by using three formworks’ methods, they are: the conventional method (According to Ministry Guide Num 1 Year 2022 and PT. Hutama Karya), the System Method with Multiplex and with phenolic film materials (According to Ministry Guide Num 1 Year 2022 and PT. Hutama Karya). This paper also included the analysis of using aluminium formwork method, but it was not the focus of this research. This analysis will also express the advantages and disadvantages of each of these methods. Data used for this research was obtained from shop drawing and calculations provided by PT. Hutama Karya (shortened as PT HK), with the prices for materials and wages for the West Java Region gathered from the Unit Price Journal. For cost estimation (calculation), the Ministry Guide Number 1 Year 2022 was used as guidance. The results of this analysis showed that the formwork with “system” Method using Phenolic film is the most economical formwork method in this study, this is because the type of formwork can be used not only multiple times, but also in buildings with varied column types.

Exploring the Stabilization of Phenolic Material and Red Wine Color through Different Polysaccharide Extraction and Addition Strategies

Exploring the Stabilization of Phenolic Material and Red Wine Color through Different Polysaccharide Extraction and Addition Strategies

Influence of surface ablation on plasma and its interaction with electromagnetic field

Surface ablation significantly affects the distribution of plasma in high-speed flow and the characteristics of its interaction with electromagnetic fields. Considering the mechanism of ablation and ejection on the surface of hypersonic vehicle, the participation of ablation products in the plasma generating process in the flow field, the conduction mechanism of mixed ionized gas containing alkali metal and the electromagnetic dynamics mechanism, the coupled calculation method of high-speed flow/plasma/electromagnetic field with alkali metal ablation is established by solving the three-dimensional thermochemical non-equilibrium flow governing equation with electromagnetic source term, the electric field Poisson equation and the magnetic vector Poisson equation. Combined with the common ablation and pyrolysis process of carbon-carbon materials and silicon-based phenolic resin materials, the mechanism and law of the interaction between surface ablation and electromagnetic field on the hypersonic plasma sheath under various conditions are systematically studied. The results show that the ablation effect affects the plasma distribution in the flow field, which is affected by the ablation mass ejection rate and the mass proportion of alkali metal. When the alkali metal content is high, the alkali metal ionization reaction is dominant, and the electron number density can increase by 1–2 orders of magnitude. The influences of different materials on plasma are different. The mass ejector ratio of silicon-based phenolic resin is larger, and the molar concentration of CO<sup>+</sup> and C<sup>+</sup> produced by ionization is close to that of NO<sup>+</sup> and <inline-formula><tex-math id="Z-20240520210947">\begin{document}${\mathrm{O}}_2^+ $\end{document}</tex-math><alternatives><graphic specific-use="online" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20231733_Z-20240520210947.jpg"/><graphic specific-use="print" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20231733_Z-20240520210947.png"/></alternatives></inline-formula>, which cannot be ignored. Alkali metal in ablative material can significantly improve the control effect of magnetohydrodynamics. With the increase of the proportion of alkali metal, the coupling effect of electromagnetic field increases, and the relationship between them is nonlinear. When the speed is low, the ionization degree of air itself is low and the coupling effect of electromagnetic field is weak. But the efficiency of “improving the electromagnetic effect by ablation of alkali metal” is higher.

Вплив вмісту фенолів на деякі експлуатаційні властивості вбирних олив

DOI: 10.31081/1681-309X-2024-0-1-15-21 Specialty 161. U.D.C. 66.074.382:665.004.12 INFLUENCE OF PHENOL CONTENT ON SOME OPERATIONAL PROPERTIES OF ABSORBENT OILS © S.V. Nesterenko, Ph.D. in Technical Sciences, (State Enterprise “Ukrainian State Research Institute for Carbochemistry (UKHIN)”, 7 Vesnina str., Kharkiv, 61023, Ukraine), A.L. Bannikov (National Technical University "Kharkiv Polytechnic Institute", 2, Kyrpychova str., Kharkiv, 61002, Ukraine) The shutdown of centralized processing of phenolic raw materials once again raises the issue of the need to implement the process of dephenolization of the wash oil and to consider the feasibility of standardizing the phenol content in it. This problem has a history as long as the use of a coal tar wash oil as absorbent for capturing benzene hydrocarbons. Recent studies have emphasized the importance of studying the effects of oil degradation initiators such as ammonia, hydrogen sulfide, resins, iron and corrosion products. The purpose of this study was to conduct an experiment to determine the effect of phenol content in the absorbing oil on certain characteristics. This was intended to provide additional arguments to justify the feasibility of implementing the process of dephenolization of benzene hydrocarbon absorbers. A mixture of phenols was added to the sample of working oil in the following approximate ratio, in which they are in the absorbing fraction, namely 30 % xylenol isomers, 5 % cresol isomers, 65 % higher phenols (β-naphthol). Electrochemical determination of the corrosion rate of the solution obtained from aqueous extracts of oil samples showed that the presence of phenols does not increase corrosion processes caused by the presence of aggressive components. It can even be argued that the presence of phenols somewhat reduces corrosion processes by forming a film on the metal surface or reducing the concentration of active components near its surface. It was found that oil with phenol additives above the usual phenol content does not show a significant increase in the tendency to coke formation. On the contrary, higher phenols are inhibitors of radical oxidation reactions, which occur up to a certain limit in the processes of coke formation. Moreover, phenols show some inhibitory effect in a fairly wide temperature range (430-800 °C). Keywords: absorbent oil, phenols, dephenolization of the heavy fraction, corrosion rate, coke number. Corresponding author: S.V. Nesterenko, e-mail: nesterhnamg@gmail.com

Frictional performance of surface-textured phenolic resin-impregnated graphite materials under water lubrication

The frictional performance between impregnated graphite materials and YG-8 cemented carbide is investigated on a self-developed rotating-type tribometer. The test configuration is a cemented carbide plate rotating against the graphite surface. Three types of concave-type textures, including linear grooves, circular dimples and isosceles triangular dimples, are fabricated by laser process on the graphite surfaces to improve the tribological properties. The test environments include dry condition and water lubrication. The corresponding friction coefficients, surface micrographs of graphite samples and cemented carbide plates are analyzed. To reveal the underlying mechanism of the frictional modification effect under water lubrication, the formation of graphite transfer film on cemented carbide plates, the water contact angles of graphite surface and the hydrodynamic effect are further discussed. It is verified that the introduction of textures on graphite surfaces can significantly improve the tribological performance of water-lubricated graphite materials.

Enzyme-mediated and formaldehyde-free formation of phenolic resin coatings

Coatings from phenolic resins are utilized in a wide range of applications and remain a crucial type of thermosetting polymers. Curing at high temperatures and the utilization of formaldehyde, however, are ever more pressing concerns. In this work, a novel approach towards phenolic resin coatings is presented. The rationale follows the concept of Enzyme-Mediated Addressing, a technique for controlled formation of coatings and structures via immobilized enzymes. Employment of Horseradish Peroxidase leads to radical induced coupling of phenol to cross-linked polymers. This well-known polymerization technique is now performed at close proximity to the support surface. Action of the enzyme is shown to lead to formation of nanoparticles from poly phenolic material and their subsequent deposition on the surface. First, important reaction parameters are investigated. From this, largely coalesced films are gained at the ideal reaction conditions. Additionally, some insight into possible process mechanisms is provided. Finally, site-specific coatings are shown to be accessible with this method as well. Due to the applied enzymatic process, formaldehyde-free cross-linking at low temperatures is achieved.

Research on the Impregnation Process and Mechanism of Silica Sol/Phenolic Resin Modified Poplar Wood

Phenolic resin-modified materials partially reduce the toughness of the wood. In this study, organic–inorganic composite modifiers were used to modify the wood. Silica sol/phenolic resin was prepared through in-situ polymerization, and poplar wood was modified using a vacuum pressure impregnation process, enhancing its toughness. Orthogonal experiments were conducted, and the impact toughness of the modified poplar wood was used as the evaluation index. Through orthogonal experiments, using the impact toughness of modified poplar as the evaluation indicator, it was found that when the average particle size of the silica sol is 8–15 nm, the pressure is 1.2 MPa, and the pressurization time is 3 h, the impregnation-modified poplar’s impact toughness reaches its optimum, improving by 84.1% and 135.4% compared to the raw material and phenolic resin impregnated wood, respectively. The Fourier Transform Infrared Spectroscopy (FT-IR) results indicated that the characteristic absorption peak of Si-O-Si appears in the poplar wood after impregnation, confirming the formation of new silicon-oxygen (Si-O) chemical bonds. X-ray Photoelectron Spectroscopy (XPS) analysis revealed that a chemical reaction occurs between the impregnation liquid and the wood, generating Si-O-C. Subsequently, through Dynamic Mechanical Analysis (DMA) and Thermogravimetric (TGA) analysis, it was understood that this chemical reaction significantly enhances the thermal stability and toughness of the impregnated material, making it superior to the original poplar material. The TGA further unveiled that, compared to untreated poplar, the thermal stability of the impregnated material has been notably improved. Lastly, Scanning Electron Microscopy (SEM) analysis demonstrated that the composite impregnation liquid successfully permeates and fills the interior of the poplar cells.

Effect of compression ratios on the sorption behaviors of bamboo fiber-based composites

The sorption behaviors of bamboo fiber-based composites (BFC) play a critical role on its applications due to its impact on the dimensional stability and biological durability of the material. The sorption behaviors of Neosinocalamus affinis BFC with compression ratios of 1.50, 1.83 and 2.17 were studied in this project, aiming to optimize the manufacturing process of BFC to reduce the sorption of final products. It was found that the hygroscopicity of BFC samples with all three compression ratios is much lower than that of raw bamboo at all the studied relative humidity (RH) levels. The BFC manufactured with 1.50 compression ratios showed the lowest equilibrium moisture content (EMC). The sorption ability of BFC showed some increase with increasing compression ratio especially when the relative humidity (RH) was above 60%. An evolution in moisture absorption model of BFC was proposed based on the changes in its wettability, pore structures, and chemical compositions. Both introduction of phenolic formaldehyde (PF) resin and material densification reduced the water transfer pathway such as bamboo cell lumens, pits, and gaps, as well as the water absorption space in cell wall. Meanwhile, the BFC with higher compression ratio had increased difficulty to absorb water. The increase in sorption ability of BFC with higher compression ratio at high RH environment is proved to be the consequence of the higher content of its mesopore ratio resulting in increased poly-layer water content. Therefore, the RH of application occasions is critical to determine the optical compression ratio of BFC combining with other performance requirements.

Investigation of Bioactivity Degradation During Storage of Sour Cherry (Prunus cerasus L.) Peel Extract.

Limited number of researches in the literature have been reported to examine degradation stability by regression methods. Monitoring storage stability of plant extracts containing phytochemicals has become a special field. This study aims to develop model equations to examine the stability of total phenolic material (TPM) and total anthocyanin (TA) in the sour cherry peel extract under several conditions, such as keeping the samples in a freezer (-20°C), refrigerator (4°C) and room temperature (25°C) conditions. In addition, two types of ambient conditions (under dark and light, respectively) were applied to observe the effect of sunlight on oxidation. The storage stability was monitored in terms of TPM and TA. 8 different polynomial regression equations were produced for the data obtained under each condition in order to define the deterioration of the TPM and TA during 60 days of the storage. Keeping the samples in the light at ambient conditions was the least efficient for stability (~10 days), while the shelf life of the product could have been quite long with the storage in the freezer after opening the package of the product. The most suitable condition for both TPM and TA has been determined as -20°C with the calculation of degradation days as 157 and 115 (R^2 = 0.9874 / 0.9265, and average error rates = 0.207097% / 0.119541%).

Colour properties and tannin concentrations of polymeric phenolic materials extracted from Pinot Noir wines of a single NZ producer

SummaryPolymeric phenolic material (PPM) was separated from monomeric anthocyanins by removing the latter using isoamyl alcohol in 22 Pinot Noir wines of different vintages and grades. The colour and tannin concentrations of PPM were determined using a modified Somers assay and methylcellulose precipitation (MCP) tannin assay, respectively. With wine age increasing, the ratio of absorbance at 520 nm at pH 1.0 to that at 3.4 decreased from 2.6 to 1.1. This decreasing trend with wine age is reported for the first time in Pinot Noir wines. The presence of bleachable polymeric pigments was also observed in PPM, and the degree of ionisation of these bleachable pigments increased along with wine age. Statistical analysis demonstrated the dominant effect of age on colour properties of PPM, regardless of vintage and grade. In contrast, total phenolics and tannin concentration mainly related to vintage, rather than age.

Ferritin Nanoshuttle for Long-Lasting Self-Healing of Phenolic Hydrogels.

Herein, we highlight a novel finding that ferritin can play a crucial role in the "self-healing lifetime" of soft phenolic materials. Ferritin interacts with a catechol-functionalized polymer to form a self-healable and adhesive hydrogel bidirectionally by providing and retrieving Fe3+. As a result of its unique role as a nanoshuttle to store and release iron, ferritin significantly increases the self-healing lifetime of the hydrogel compared with that afforded by catechol-Fe3+ coordination through direct Fe3+ addition without ferritin. Ferritin also induces stable oxidative coupling between catechol moieties following metal coordination, which contributes to double cross-linking networks of catechol-catechol adducts and catechol-Fe3+ coordination. Thus, ferritin-mediated cross-linking can provide phenolic hydrogels with the advantages of hydrogels prepared by both metal coordination and oxidative coupling, thereby overcoming the limitations of the current cross-linking methods of phenolic hydrogels and broadening their versatility in biomedical applications.

Thermal oxidation and compressive failure behavior of ZrSi2–B4C modified phenolic resin-based composite

Phenolic resin-based ablative materials have gained significant attention in the aerospace sector in recent years. In this study, TGA-DSC, FT-IR, XRD and XPS were employed to the thermal stability and phase transformation of the ZrSi2–B4C modified quartz fiber/boron containing phenolic resin (QF/BPR) composite. The compressive failure behavior of the composite at 600–1200 °C was studied through SEM and high-speed camera techniques. The results indicated that the compression strength of the composite decreased to a minimum at 600 °C and increased at 800–1200 °C. The composite exhibited different failure modes at different temperature: shear fracture at room temperature (RT), debonding of the fiber bundles at 600 °C, fiber buckling and fiber shear fracture at 800 °C, fiber buckling and delamination at 1000–1200 °C. The improvement in thermal stability of composite was primarily attributed to the formation of ZrO2, SiO2 and B2O3, which covered the fiber and effectively transmitted the load, leading to an enhanced strength of the interface between the fiber and resin.

Visible Light-Driven Sandwich-like g-C3N4-Catalyzed Oxidation to Produce Cumene Hydroperoxide

Cumene hydroperoxide (CHP) is an important intermediate for the production of phenol, acetone, propylene oxide, and other raw materials in the petrochemical industry. However, due to the high reaction temperature and pressure, the current process for the industrial production of CHP has problems of potential safety hazards and high energy consumption. In this work, carbon nitride (g-C3N4) with a unique sandwich structure was discovered as a photocatalyst. It efficiently activates molecular oxygen in the air, oxidizes cumene (CM) to prepare CHP, and realizes high atom economy transformation at room temperature, atmospheric pressure, and solvent-free conditions. The continuous flow strategy was adopted to improve the gas–liquid mass transfer efficiency and reduce the phenomenon of back-mixing, thereby reducing the decomposition of the products and improving the product selectivity. The conversion rate was the same as that of the batch reaction, reaching 23%. The selectivity of the product CHP increased from 82 to 92%, and the reaction residence time was shortened from 10 h to 70 min. The catalysts have the advantages of high efficiency, easy availability, environmentally friendly, etc., and are recyclable and stable. This work provides a new strategy for establishing green, sustainable, clean, and efficient methods for the preparation of peroxides.

Arc-Jet Tests of Carbon-Phenolic-Based Ablative Materials for Spacecraft Heat Shield Applications.

We developed and tested two carbon-phenolic-based ablators for future Korean spacecraft heat shield applications. The ablators are developed with two layers: an outer recession layer, fabricated from carbon-phenolic material, and an inner insulating layer, fabricated either from cork or silica-phenolic material. The ablator specimens were tested in a 0.4 MW supersonic arc-jet plasma wind tunnel at heat flux conditions ranging from 6.25 MW/m2 to 9.4 MW/m2, with either specimen being stationary or transient. Stationary tests were conducted for 50 s each as a preliminary investigation, and the transient tests were conducted for ~110 s each to stimulate a spacecraft's atmospheric re-entry heat flux trajectory. During the tests, each specimen's internal temperatures were measured at three locations: 25 mm, 35 mm, and 45 mm from the specimen stagnation point. During the stationary tests, a two-color pyrometer was used to measure specimen stagnation-point temperatures. During the preliminary stationary tests, the silica-phenolic-insulated specimen's reaction was normal compared to the cork-insulated specimen; hence, only the silica-phenolic-insulated specimens were further subjected to the transient tests. During the transient tests, the silica-phenolic-insulated specimens were stable, and the internal temperatures were lower than 450 K (~180 °C), achieving the main objective of this study.