Frame Material Research Articles

A finite element analysis of auxetic composite fabric with rotating square structure

The auxetic property of macro-porous rotating square structure has been investigated by many using either experimental or numerical approaches. Given the low breaking strength of the typical rotating square structure, it was proposed to employ an elastic base material to the cellular auxetic structure to improve its strength while maintaining its auxetic behavior in our previous study. Despite the experimental studies conducted, a numerical analysis is needed to explain the auxetic effect found in the produced laminated fabrics. In this paper, the auxetic properties of the 2-layer laminated system were simulated using the finite element approach and the effects of the modulus difference between the frame and the base were discussed. The main findings are (1) the simulated results based on a simplified model are broadly consistent with experimental ones under low tensile strain ranges; (2) the initial modulus of the frame material in the stretched direction and that of the base material in the lateral direction are critical to the generation of auxetic effect in the laminated system; (3) at least a 10-time difference of the modulus between the frame and the base materials is required to generate an auxetic effect in the 2-layer laminated structure and the overall auxetic property is increased by enlarging difference of the modulus within a tolerance. It is expected that this research could provide an instructive reference for the future design of auxetic materials.

An effective geometric nonlinear analysis approach of framed structures with local material nonlinearities based on the reduced-order Newton-Raphson method

The P-Δ effect is essential to be considered in the quasi-static pushover or horizontal seismic analysis of high-rise framed structures. Owing to the presence of the P-Δ effect, however, the geometric stiffness varies with the members’ internal variables (such as axial force and relative lateral displacement). Using a conventional nonlinear analytical process, each iteration has to update the structural effective stiffness even though the material remains elastic. Consequently, it requires a tremendous amount of computational effort in the material and geometric (double) nonlinear analysis of large-scale frames. To alleviate this disadvantage, this study presents an efficient and accurate nonlinear analysis approach for the high-rise framed structure considering the P-Δ effect. Assuming an invariant (time-independent) vertical load of each storey after the gravity analysis, the structural geometric stiffness induced by the P-Δ effect is then constant. Accordingly, the conventional double nonlinear system could be converted into an equivalent material nonlinear one whose effective stiffness contains material and geometric components. After that, a reduced-order Newton-Raphson method is employed to simplify the iterative analysis of the global system into that of a reduced subsystem comprised by yielding elements. Four application cases demonstrated the accuracy and reliability of the presented geometric nonlinear analysis approach. Predictably, the presented strategy will considerably improve the efficiency of double nonlinear analysis of the tall framed structure with local material nonlinearities.

Efficient and selective removal of Pb2+ from aqueous solutions by modified metal-organic frame materials

The broad application of lead in various industries has caused it to accumulate in the environment, with severe implications for human health. There is an urgent need to develop efficient separation materials for treating lead-containing wastewater. In this study, a novel metal-organic framework material (UIO-66-TETA) was prepared using triethylenetetramine (TETA) as a modifier and applied to remove Pb2+ from water. The material was characterized by SEM, EDS, BET, XRD, FTIR, XPS, and other analytical methods. The results indicated that TETA was successfully introduced into the material surface, and the original crystal structure and morphology were maintained. The effects of pH, contact time, initial Pb2+ concentration, and temperature on Pb2+ removal were systematically investigated. Adsorption experimental data were consistent with the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model. The adsorption thermodynamic analysis revealed that the adsorption process was endothermic and spontaneous. UIO-66-TETA had excellent adsorption selectivity for Pb2+ even in a mixed solution containing many other heavy metal ions. Regeneration experiments showed that UIO-66-TETA has good regeneration performance. Based on the results obtained in this work, it can be concluded that UIO-66-TETA can be used as an ideal adsorbent for the removal of Pb2+.

Influence of load partial factors adjustment on reliability design of RC frame structures in China

The partial factor method has been widely used in building design and the partial factors to ensure the safety of structures are specified in the adopted codes. The load partial factors in the design expressions have been increased in the lasted code in China, which leads to theoretically increment in reliability and a growth in the consumption of construction materials. However, the influence of load partial factors adjustment on design of building structures arises different points among scholars. Some believe that it has a great impact on the design, some think the influence is small. This makes designers have doubts in the safety of structures and investors are also confused about the cost. In order to illustrate the influence of load partial factor adjustment on safety level and material consumption of RC (Reinforced Concrete) frame structures, reliability analysis and material consumption analysis are performed using First Order Reliability Method (FORM). The approach is carried out according to the load partial factors in Chinese codes of (GB50153-2008) and (GB50068-2018), respectively. Then, the influence of load partial factors adjustment is demonstrated with a case design of RC frame structures with different load partial factors in codes. The results show that the partial factor has a noticeable influence on the reliability index. The adjustment of load partial factors in design leads to an increase of the reliability index, which is about 8–16%. The increase of material consumption used in RC structures is about 0.75–6.29%. And the case indicated that the adjustment of load partial factors mainly result in the increase of reinforcement consumption, while have little effect on the concrete consumption. This study provides an analytical and conclusive insight into the influence of load partial factor adjustment on safety level and material consumption, which is can be applied to a wide range of structures.

Metal Oxide Removal Using Atmospheric Pressure Plasma Technology for Electronic Applications

Copper is one of the most commonly used metals in the electronics industry. For example, it is extensively used as a lead frame material in integrated circuit packaging due to its superior thermal and electrical conductivity and low production cost. However, the formation of a native oxide on the surface along with the presence of organic contaminants hinder wire bond strength. The work presented here will focus on a novel approach to remove copper and other oxide layers using a nitrogen/hydrogen (95%/5%) gas plasma chemistry that does not require a vacuum environment. The processes are run at temperature conditions lower than 200°C, and at speed up to 150 mm/s which make the technology attractive for industrial upscaling. Results from the elemental analysis using scanning electron microscopy (EDS-SEM) of the plasma-treated versus as-received copper surfaces will be presented. Also, a brief analysis of the gas plasma-surface interactions, process parameters leading to oxide reduction of various metals (Cu, Sn) and equipment details will be discussed. Aside from improving wire bond strength to lead frames and pads, plasmas can be used to improve die attachment to various metal solder materials for flip chip and other electronic applications.

Forward osmosis membrane doped with water-based zirconium fumarate MOFs to enhance dye pollutant removal and membrane antifouling performance.

Metal-organic frameworks (MOFs) can be applied to enhance the property of forward osmosis membranes. However, organic solvents can easily remain in organic synthetic metal-organic frame materials and cause membrane fouling and a decrease in membrane permeability. In this study, water-based Zr-fumarate MOFs were synthesized and doped into the membrane active layer by interfacial polymerization to provide a water-based MOF-doped thin-film composite membrane (TFC membrane). It was found that doping the water-based MOFs effectively improved membrane hydrophilicity, and nanowater passages were introduced in the active layer to improve permeability. The water flux of the water-based MOF-doped TFC membranes was increased by 21% over that of the original membrane, and the selectivity performance of the membrane was improved while keeping the salt rejection basically unchanged. Additionally, the water-based MOF-doped TFC membrane showed good removal efficiency (Rd > 94%) and strong antipollution performance in the treatment of dye pollutants.

Heat Transfer Characteristics of Particle and Air Flow Through Additively Manufactured Lattice Frame Material Based on Octet-Shape Topology

Abstract Particle-to-supercritical carbon dioxide (sCO2) heat exchanger is a critical component in next-generation concentrating solar power (CSP) plants. The inherently low heat transfer between falling particles and sCO2 imposes a challenge toward economic justification of levelized cost of electricity produced through solar energy. Introduction of integrated porous media with the walls bounding particle flow has the potential to enhance the overall particle-to-sCO2 heat exchanger performance. This paper presents an experimental study on heat transfer characterization of additively manufactured lattice frame material based on Octet-shaped unit cell with particles and air as working fluids. The lattice structures were additively manufactured in stainless steel (SS) 316L and SS420 (with 40% bronze infiltration) via Binder jetting process, where the lattice porosities were varied between 0.75 and 0.9. The mean particle diameters were varied from 266 μm to 966 μm. The effective thermal conductivity and averaged heat transfer coefficient were determined through steady-state experiments. It was found that the presence of lattice enhances the effective thermal conductivity by 2–4 times when compared to packed bed of particles alone. Furthermore, for gravity-assisted particle flow through lattice panel, significantly high convective heat transfer coefficients ranging from 200 W/m2K to 400 W/m2K were obtained for the range of particle diameters tested. The superior thermal transport properties of Octet-shape-based lattice frame for particle flow makes it a very promising candidate for particle-to-sCO2 heat exchanger for CSP application.

Vacancy and doping engineering of Ni-based charge-buffer electrode for highly-efficient membrane-free and decoupled hydrogen/oxygen evolution

The realization of the membrane-free two-step water electrolysis is particularly important yet challenging for the low-cost and large-scale supply of hydrogen energy. In this effort, Co-doped Ni(OH)2 nanosheets were successfully anchored onto the nickel foam (NF) substrate through the in-situ growth of metal-organic frame material and the subsequent alkali-etching technique. Using the well-regulated Co-doping Ni(OH)2@NF electrodes as a charge mediator, electrochemical hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were decoupled on time scales, thus affording a membrane-free two-step route for H2 and O2 productions. In this architecture, the first HER process on the cathode could be maintained for 1300 s at a current of 100 mA, while the corresponding Ni(OH)2 charge mediator was simultaneously oxidized to NiOOH, with a decent cell voltage of 1.542 V. The subsequent OER process involved a reduction/regeneration of Ni(OH)2 (from NiOOH to Ni(OH)2) and an anodic O2-production, with an operating voltage of 0.291 V. Moreover, the Ni-Zn battery assembled through the combination of NiOOH and Zn sheet could replace the second step of OER to achieve the coupling of continuous H2-production and battery discharge, thus also providing a new way for hydrogen production without an external power supply. Experiment and theoretical calculations have shown that the cobalt-doping not only improved the conductivity of the charge-buffer electrode, but also shifted its redox potential cathodically and boosted the adsorption affinity of the buffer medium to OH– ions, both contributing to promoted HER and OER activity. Therefore, this decoupled water electrolysis device affords a promising pathway to support the efficient conversion of renewables to hydrogen.

AIE-based cyclodextrin metal–organic frame material for fluorescence detection of nitrofuran and tetracycline antibiotics in aqueous solution

The problem of antibiotic residues is very serious and is harmful to the ecological environment and the human body. We have developed a method for the rapid detection of antibiotics in water samples. Firstly, we prepared a fluorescent material (TPE@CLMOF) with cyclodextrin cross-linked MOF (CLMOF) and tetraphenylethylene (TPE) using a simple way. Due to diphenyl carbonate cross-linking, the fluorescent MOF can glow stably in water. Compared with TPE (40.1%), the absolute quantum yield of TPE@CLMOF increases to 63.2%. The fluorescence of TPE@CLMOF can be selectively quenched by Nitrofurans (NFs) and Tetracyclines (TCs) antibiotics in water. The detection limits of nitrofurazone, nitrofurantoin and chlortetracycline are 0.11, 0.13 and 0.16 μM, respectively. We have studied the adsorption of nitrofurazone, nitrofurantoin and chlortetracycline in TPE@CLMOF and the Langmuir adsorption model and pseudo-second-order kinetic model were established. The maximum adsorption capacity is 223, 209 and 185 mg g−1, respectively. We also proposed a dual quenching mechanism of electron transfer and internal filtration effect, which is verified by quantum chemical calculations and experiments. Finally, the TPE@CLMOF was successfully used as a fluorescent sensor for the determination of antibiotic spiked honey samples.

Effects of inherent surface roughness of additively manufactured lattice frame material on flow and thermal transport

Additively manufactured (AM) fiber-based lattice topologies provide superior thermal and mechanical performance. For true characterization of flow and thermal transport of AM lattices based on different unit cell topologies, it is imperative to understand the role of inherent surface roughness of AM parts on the same. To this end, the effect of inherent roughness on the endwalls and fibers of a tetrakaidecahedron unit cell-based lattice on the flow and thermal transport has been computationally studied here for Reynolds number of 9,806. The predictions were compared to the heat transfer coefficient values obtained from the experiments conducted on tetrakaidecahedron coupon additively manufactured in Stainless steel 420 (SS 420) using Binder-Jetting process. The AM parts were characterized using X-ray computed tomography (CT) scan and optical profilometer. For the computational study, artificial roughness was generated such that the roughness characteristics were similar to the AM parts. First set of analysis includes the as-designed smooth CAD geometry with desired lattice porosity of 0.886 and as-manufactured geometry with the rough endwalls and fibers having manufactured porosity of 0.856. The as-designed geometry underpredicted the velocity magnitudes and turbulent kinetic energy levels as compared to the as-manufactured counterpart. The overall heat transfer coefficient values were under-predicted by 26.8% and 13.9% from the experimental data, respectively. The second set of analysis included two geometries-(i) smooth endwall and rough fiber, and (ii) rough endwall and smooth fiber, both having manufactured lattice porosity of 0.856. The overall heat transfer coefficient values in the rough fiber-only and rough endwall-only deviated by 14.2% and 18.9% respectively. Amongst all the four geometries simulated, the as-manufactured part with roughness on both the endwalls and fibers provided the best agreement with the experimental results suggesting that the roughness effects cannot be overlooked for accurate thermal performance predictions. The rough fiber-only case provided better results than the rough endwall-only case suggesting that the roughness of the fibers accounting for the porosity deviations is important in dictating the overall lattice heat transfer performance. However, the endwall effects can become increasingly significant if the roughness scales become comparable to the global unit cell dimensions.

Comparison of Household Environmental Factors among Children with Reported Asthma and Controls

The present research was part of a cross-sectional project involving children aged 8 to 10 years in Porto, Portugal. The project involved a first research part at primary schools where the health tests and a questionnaire were performed and a second research part concerning environmental conditions. Two groups emerged from the health questionnaire answers: one group that reported “asthma diagnosed by a doctor” and/or “wheezing or whistling in the chest during last 12 months” and another that answered negatively to both questions. After performing the health questionnaire based on ISAAC, the children responsible were invited to participate in the environmental part of the study. The outdoor and indoor potential risk factors were extensively evaluated in children's homes. This research aimed to compare housing characteristics and indoor behaviours as environmental risk factors in the two children group and investigate whether the risks found are common. The results indicate that windows open during cleaning, standard window frame material, animals at present, dog presence, cat presence, sweep, and vacuumed floor cleaning were associated with both groups. This demonstrates that home characteristics influence some risks and may be exacerbated by certain occupants' behaviours.

Structure Simulation on Portable Commuter Bike Considering Frame Design and Materials Alternatives

Portable commuter bikes (PCBs) are needed by commuters, people who live in the suburbs of a city and whose activities are in the middle of the city or vice versa, even for longer distances. For user safety, it is mandatory to check the strength aspect of the bicycle frame structure. PCBs are not only ridden by the commuter but can also be folded to bring them along on public transportation. The PCB design also included a stool to be used by the commuter while waiting for the bus or train. The strength of the PCB structure was investigated using numerical simulations based on static load. The displacements and stresses were controlled using a variety of PCB frame designs and materials. The results of this bicycle structural inspection can guide the improvement of PCB designs in the future.

The Mechanical Characteristics of the Neck Zone for a PEMFC Stack

Generally, the unit cell in a proton exchange membrane fuel cell (PEMFC) stack is divided into different zones according to the characteristics of the bipolar plate. There is a zone that has been neglected, which we define as the “neck zone” for the first time in this work. Uneven stress and deformation are prone to appearing in the neck zone due to its unique structure. A three-dimensional finite element model was applied to study the influence of the membrane electrode assembly (MEA) frame materials on the mechanical characteristics of the neck zone. In addition, the sealing and the water–gas transport performances of the neck zone were evaluated via the stress fluctuation and deformation. It was found that even with the commercial polyethylene naphthalate (PEN) frame, a leak point would be generated at the region with the lowest stress, reducing the performance and even causing safety hazards. The invasion rate was proposed to assess the water–gas transport ability. When an inappropriate frame material was adopted, the invasion rate went up to 32.4%, severely hindering the water and the air transport. It was concluded that MEA frames with a higher elastic modulus and thickness are preferred for the neck zone to obtain a high property of sealing and water–gas transport.

Comprehensive reutilization of herbal waste: Coproduction of magnolol, honokiol, and β-amyrin from Magnolia officinalis residue

Herbal extraction residues (HERs) cause serious environmental pollution and resource waste. In this study, a novel green route was designed for the comprehensive reutilization of all components in HERs, taking Magnolia officinalis residues (MOR) as an example. The reluctant structure of MOR was first destroyed by alkali pretreatment to release the functional ingredients (magnolol and honokiol) originally remaining in MOR and to make MOR more accessible for hydrolysis. A metal–organic frame material MIL-101(Cr) with a maximum absorption capacity of 255.64 mg g−1 was synthesized to absorb the released honokiol and magnolol from the pretreated MOR solutions, and 40 g L−1 reducing sugars were obtained with 81.8% enzymatic hydrolysis rate at 10% MOR solid loading. Finally, 382 mg L−1 β-amyrin was produced from MOR hydrolysates by an engineered yeast strain. In total, 1 kg honokiol, 8 kg magnolol, and 7.64 kg β-amyrin could produce from 1 ton MOR by this cleaner process with a total economic output of 170,700 RMB.

Comparison of heat transfer enhancement between open and closed cell porous metal structures for solid–liquid phase change

PurposeThe purpose of this study is to analyze heat transfer for solid–liquid phase change in two inclined cavities assisted with open cell and closed cell porous structures for enhancement of heat transfer and compare them.Design/methodology/approachThe heat transfer analysis is done numerically. The set of conservation equations for mass, momentum and energy for phase change material (PCM) and conduction heat transfer equation for metal frame are solved. Furthermore, temperature and solid–liquid fraction distributions for a cavity filled only with PCM are also obtained for comparison. The porosity is 0.9 for both porous structures. Rayleigh number and inclination angle change from 1 to 108, and from −90° to 90°, respectively.FindingsThe present study reveals that the use of closed cell structures not only can make phase change faster than open cell structure (except for Ra = 108 and = 90°) but also provide more stable process. The use of a closed cell porous structure in a cavity with PCM can reduce melting period up to 55% more than a cavity with an open cell porous structure. The rate of this additional enhancement depends on Rayleigh number and inclination angle.Originality/valueTo the best of the authors’ knowledge, this is the first time that the comparison between closed cell and open cell porous structures for heat transfer enhancement in a solid/liquid phase change process is reported. Authors believe that the present study will lead more attentions on the use of closed cell porous structures.

Damage States Investigation of Infilled Frame Structure Based on Meso Modeling Approach

The non-linear behavior of infilled frames is very complex. The behavior of this structure may be studied by experimental and numerical approaches. An experimental test can provide a more realistic output but has the disadvantages of high costs, relatively long time and specific room usage. A numerical analysis can be an alternative to analyze the behavior of infilled frames. One of the most powerful numerical approaches is meso-modeling. This approach has the advantage of being able to capture local damage to the panel. For this reason, the progressive damage identified in the meso-model can be used as a basis for determining damage state criteria. The grouping of damage states is proposed based on the initial identification in the form of local damage linked to global damage, i.e., IDR. This study’s proposed level of infilled frame damage is DS1 = 0.17%, DS2 = 0.52%, DS3 = 0.79% and DS4 = 1.99%. However, the quantification results of the structural damage level cannot be generalized because many complex factors influence the behavior of infilled frames. Subsequently, a parametric study was carried out to determine the contribution of the mechanical properties of the infilled frame material to the degree of structural damage.

Thorium and uranium trace ICP-MS analysis for AMoRE project

AMoRE (Advanced Mo-based Rare process Experiment) is an international collaboration searching for the neutrinoless double-beta decay of the 100Mo isotope with cryogenic detectors using molybdate (100MoO4)-based scintillation crystals. The process requires that the detector apparatus and its components, including bolometric crystals and thus initial materials used for the crystal growth, be extremely low in radioactive isotopes having decays that may generate background noise signals in the region of interest. The present study summarizes an ICP-MS assay program conducted for the AMoRE experiment. Firstly, the 100MoO3 powder, the main component of the crystals, was studied in the analysis. Before crystal synthesis, enriched 100MoO3 powder was purified at the Center for Underground Physics (CUP). To ensure its radio purity, a sample preparation technique with a UTEVA® resin was developed for Th and U analysis with ICP-MS. The recovery yield was over 90% for the extraction procedure, and the detection limits for Th and U were 2.3 and 1.0 ppt, respectively. To determine the most appropriate material for the detector frame and shielding, several types of high-purity Cu were measured: Cu-OFE (Aurubis and Mitsubishi Materials) and Cu–NOSV (Aurubis). Similarly, a solid-phase extraction was applied for Th and U analysis, and detection limits were calculated at 0.1 and 0.2 ppt, respectively. The 3M Vikuiti™ ESR film, the closest part to the crystal in the detector assembly, was used as a light reflector. Two types of Vikuiti film, a roll and a sheet, were checked for radiopurity via full decomposition using a microwave ashing system. The procedural Detection Limits were achieved at a level of about 1 ppt.

What really matters in multi-storey building design? A simultaneous sensitivity study of embodied carbon, construction cost, and operational energy

Buildings account for over one-third of global emissions and energy use. Meeting climate pledges will require achieving high operational energy efficiency with low embodied impacts in new construction. Yet, a systematic identification of the relative influence of building design parameters on both operational and embodied efficiencies has rarely been attempted. In this paper we explore for the first time the sensitivity of a wide range of design and operation parameters in terms of embodied carbon, construction cost, as well as heating and cooling loads for multi-storey buildings. We devised a model to estimate the relative importance of a large set of input variables, describing a building’s shape, size, layout, structure, ventilation, windows, insulation, air, and use for residential and office multi-storey buildings, across different climates. We found that increasing building compactness, using steel or timber instead of concrete frames, lowering window-to-wall ratio, choosing the most suitable glazing, and employing mechanical ventilation with heat recovery are the most important measures to decrease embodied emissions and operational energy. The most significant trade-offs with construction cost were found for the choice of frame material and in the decision whether to install mechanical ventilation. We estimate that 28–44% of yearly heating and cooling energy and 6 Gt cumulative embodied CO2e until 2050 could be saved in multi-storey buildings, without employing new technologies.

Preparation of 3D Frame Material for Lithium Metal Battery Anode Based on Waste Lithium-ion Battery Anode Graphite

With the increase of waste lithium-ion batteries (WLIBs), the recycling of WLIBs has been paid more attention. Lithium metal battery (LMB) has extremely high theoretical specific capacity. However, the decline of cycle performance and the danger of short circuit caused by lithium dendrite formation and dead lithium accumulation are still the most thorny problems for the anode of LMB. Herein, the high value utilization of WLIBs anode graphite was explored, and it was prepared as a 3D frame material for LMB. Liquid-phase reduced graphite oxide nanosheets (lrGO) were prepared from AG, then, ZnO nanoparticles were loaded on lrGO. SEM, EDX and XRD were used to characterize lrGO and lrGO-ZnO , and the electrochemical tests were carried out. The results showed that lrGO and lrGO-ZnO maintained excellent cycle stability. Under the constant current density of 1mA cm-2, the stable cycle of lrGO-ZnO was 700 cycles, and the charge-discharge platform potential difference maintained at 22.5 mV after 200th cycle. The unique 3D structure of lrGO increased the electrode reaction area and suppressed the volume expansion of Li. The loading of ZnO significantly improved the lithiophilicity and cycle stability.

Analysis of the Performance of Natural Composite Materials Reinforced with Sago Sheath Fibers as an Alternative Material in Overcoming the Effect of Urban Heat Islands on Buildings

Local knowledge of a region is an asset that encourages the identification of a region. Hence, the specificity, uniqueness, and character that animates a particular city can distinguish it significantly from other cities. Sago tree fronds are widely applied to buildings as an alternative material for making tiles for roofs and other parts of buildings. The sago palm has long been used for making roofs and walls, especially in traditional houses. Few previous studies have used sago fronds as a manufacturing material for traditional houses. However, based on data in the field, many traditional houses still use sago fronds as a roof and wall framing material. This is also an effort to overcome the urban heat island phenomenon (UHI) in buildings. The UHI phenomenon is a phenomenon of urban development that highly affects environmental quality conditions and causes microclimate changes where air temperature conditions in urban areas are higher than the surrounding air temperatures. Sago midrib fiber is a natural composite material used as a reinforcing material for natural composite materials due to its thermal and mechanical properties. Composite materials using the hand lay-up technique—with characterization methods including the impact test and the DSC test, variations in NaOH levels, and variations in the resin–catalyst matrix—were used in this study. The results obtained were then compared with those in the literature. The results showed that 6% NaOH obtained the most significant impact value of 2.1 J, and the resin–catalyst matrix variation of 97.5%:2.5% obtained the most significant impact value, which was 2.4 J. Meanwhile, the DSC test results showed that the material’s best value for retaining heat was at 4% NaOH content variation and a resin–catalyst matrix variation of 97.5%:2.5%.