Thermal Stability Of Epoxy Resin Research Articles

Phenyl propyl polysiloxane modified epoxy resin I: The content, phase structures and macroproperties

Polysiloxanes are known to significantly enhance the toughness and thermal stability of epoxy resins. However, the study of phase transitions and their effects on the properties of modified resins, synthesized through copolymerization or blending, was quite limited. In this work, a phenyl propyl polysiloxane (PPPS) modified epoxy resin (P/E) was prepared using a solvent method to scrutinize the influence of varying PPPS concentrations and phase transitions on the macroscopic properties of the resin. The molecular structure of P/E composite was confirmed through Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H and 29Si NMR) analysis. Based on atomic force microscopy (AFM) results, the progression of phase transitions was deduced: from a homogeneous phase to a co-continuous phase, and subsequently to a sea-island phase. This progression of phase transitions is attributed to the varying solubility of the copolymer with different PPPS content in the resin. At a PPPS content of 20 wt%, a significant improvement in tensile strength (σ) and critical strain energy release rate (GIc) was observed, increasing by 45 % and 400 %, respectively, upon the formation of a co-continuous phase. The presence of a silicone-rich spherical domain within sea-island phase can significantly improve the GIc of the resins, while this also results in a rapid reduction in tensile strength (σ). Furthermore, the thermal stability of P/E composite is also affected by its phase structures. The silicone-rich spherical domains are more effective in forming a protective layer compared to the co-continuous phase, which leads to a decreased pyrolysis rate and an increased yield of residual char. This work elucidates the influence of PPPS content and phase structure on the macroscopic properties, highlighting the significant potential for developing composite materials with superior comprehensive performance.

Low-concentration octadecylamine based nano cellulose prepared by acid hydrolysis method improving the toughness and thermal stability of epoxy resin

Modified cellulose nanocrystals were prepared by hydrolyzing softwood pulp board with acrylic acid and p-toluenesulfonic acid, and then the nano cellulose was modified by introducing Octadecylamine into the nano cellulose. Then the modified nano cellulose was dispersed in epoxy resin (EP) to obtain Octadecylamine (ODA) modified nano cellulose-based epoxy resin composites (ONCA/EP) with high strength and good toughness. Moreover, the problem of poor dispersion of nano cellulose in EP is improved. FTIR and X-ray diffraction (XRD) confirmed the modified nano cellulose.The application properties were determined through particle size analysis, thermogravimetric analysis (TGA-DSC), mechanical property analysis, TEM and SEM. ONCA/EP nano composites have excellent mechanical properties and thermal stability due to inadequate concentration of modified nano cellulose doping. The results show that by introducing 2 % ONCA only, the strength reached the highest 74.03 MPa, and the elongation at break reached 3.64 %; the residual mass at 800℃ increased by 3.68 % compared to pure EP. The research utilizes biodegradable nano cellulose for EP modification, opening up new avenues for the applying of nano cellulose in the field of materials science. It is of great significance in enhancing epoxy resin's performance, promoting sustainable materials' development, and expanding the application areas of nano cellulose.

Investigation on the effect of multiwalled carbon nanotubes in carbon fiber‐reinforced epoxy composites manufactured using vacuum infusion process and hand layup process followed by vacuum bagging

AbstractEpoxy/carbon fiber (CF) composites are widely used for structural applications owing to their exceptional mechanical and physical characteristics. The main aim of this work is to individually analyze the impact of multiwalled carbon nanotubes (MWCNTs) as nanofillers in epoxy/MWCNTs/CF composites prepared by vacuum infusion process (VIP) and hand layup followed by vacuum bagging technique (HLVB). Optimal Manufacturing Strategies were followed at various stages of manufacturing which include the selection of effective dispersion technique for MWCNTs, identification of optimal weight percentage of MWCNTs in epoxy/MWCNTs nanocomposites and preparation of epoxy/MWCNTs/CF composites. For HLVB samples, tensile and flexural strengths increased from 337.5 to 475 MPa and 615.40 to 677.09 MPa. For VIP samples tensile and flexural strengths increased from 371 to 521 MPa and 714.19 to 769.02 MPa. Thermogravimetric analysis (TGA) indicated improvement in the thermal stability of epoxy with the incorporation of MWCNTs/CF and improved weight percentage retention of 84.7% at 375°C. Fracture analysis of the epoxy/MWCNTs/CF composites prepared using VIP were analyzed by FE‐SEM and revealed that constant fiber rupture caused by better interface and improved bridging mechanism eventually led to enhanced mechanical performance. The predominant immediate fracture mechanism of MWCNTs also indicated this improved interfacial interaction.Highlights Pull‐out fracture mechanism was predominantly seen in high viscous epoxy/MWCNTs composites Immediate fracture mechanism of MWCNTs were predominant in low viscous epoxy/MWCNTs sample Constant fiber rupture of VIP samples indicated improved fiber matrix interface Incorporation of MWCNTs showed improved weight percentage retention 0.5 wt% MWCNTs incorporated VIP epoxy/CF composites showed improved performance

Simultaneous improvement impact strength and thermal stability of epoxy resin by using bio-silica and a thermoplastic

Simultaneous improvement impact strength and thermal stability of epoxy resin by using bio-silica and a thermoplastic

Effects of different metal ions in phosphonitrile-modified organometallic complexes on flame retardancy of epoxy resin

Two organometallic (Zn and Fe) coordination compounds, modified by phosphonitrile, were prepared by solvothermal method. The introduction of the two organometallic coordination compounds significantly improved the flame retardancy, smoke suppression and thermal stability of epoxy resins (EP). Especially, zinc-containing coordination compounds exhibited higher efficiency than iron-containing ones in flame-retardant EP. LOI values of Zn-PDH/EP and Fe-PDH/EP were further enhanced and reached up to 29.8% and 28.9%, respectively. Organometallic coordination compounds modified by phosphonitrile mainly exerted the flame-retardant action in condense phase by the combined effect of the catalysis charring effect of metal ions and flame-retardant effect of phosphonitrile, and thus a high-temperature stable graphitized carbon layer with P- and N-containing cross-linking structures formed. This high-quality carbon layer was a vital factor in improving the heat/smoke suppression properties of EP thermosets. Further, due to the weaker catalytic char-forming effect of iron ions and the formation of fewer cross-linked structures, the strength and barrier properties of the Fe-PDH/EP char layer were relatively lower than those of Zn-PDH/EP. Consequently, Zn coordination compounds presented higher efficiency in suppressing heat/smoke release of EP matrix than Fe hybrids. Finally, the gas-phase function of organometallic coordination compounds should not be overlooked due to releasing phosphorus-oxygen free radicals and N-containing fragments during pyrolysis, exhibiting flame inhibition and dilution effect in gas phase, especially for 6%Zn-PDH/EP.

The Effect of Polyepoxyphenylsilsesquioxane and Diethyl Bis(2-hydroxyethyl)aminomethylphosphonate on the Thermal Stability of Epoxy Resin.

Polyepoxyphenylsilsesquioxane (PEPSQ) and diethyl bis(2-hydroxyethyl) aminomethylphosphonate (DBAMP) can improve the flame retardancy of epoxy resin (EP). In this paper, the results of the limiting oxygen index (LOI) and UL94 tests exhibited that PEPSQ and DBAMP had good synergistic flame retardancy. The non-isothermal degradation kinetics of EP containing PEPSQ and DBAMP was investigated by the Kissinger and Flynn-Wall-Ozawa methods. The results of the Kissinger method displayed that the addition of two flame retardants, PEPSQ and DBAMP, can slightly enhance the activation energy of EP, indicating that the additives delayed the thermal degradation of EP. The Flynn-Wall-Ozawa method further confirmed that the activation energy of EP during the whole thermal degradation process can be significantly increased by addition of the two flame retardants PEPSQ and DBAMP. When the degree of conversion exceeded 80%, the increase was more significant. This illustrated that the flame retardants finally achieved the purpose of improving the flame retardancy of EP by stabilizing the char layer.

Toughening and strengthening of low-temperature resistant epoxy resins by introducing high-performance thermoplastic resin with phthalazinone structure

This paper used phthalazinone-based copoly(biphenyl ether nitrile) (co-PPEN) to improve the low-temperature toughness of epoxy resin E51. The effects of co-PPEN content on the normal/low-temperature mechanical properties, thermomechanical properties, and thermal stability of epoxy resins were studied. Results showed that co-PPEN significantly improved the normal/low-temperature mechanical properties of E51. At room temperature, the impact strength, flexural strength, and tensile strength of co-PPEN/E51 blends increased by 144.0%, 12.8%, and 28.1%, respectively; at low temperature, the impact strength, flexural strength, and tensile strength of co-PPEN/E51 blends increased by 87.9%, 43.6%, and 18.5%, respectively. From the cross-sectional analysis, the crack deflection and crack bridging of co-PPEN are the main toughening mechanisms of the blends. The blend system has high thermal property, and the glass transition temperature of the co-PPEN/E51 blend increased by about 50 °C. Simultaneously, all blends exhibited better thermal stability.

High Temperature Performance of Concrete Confinement by MWCNT Modified Epoxy Based Fiber Reinforced Composites.

The conventional method of fiber reinforced polymer (FRP) wrapping around concrete columns uses epoxy as the binder along with synthetic or natural fibers such as carbon, glass, basalt, jute, sisal etc. as the reinforcement. However, the thermal stability of epoxy is a major issue in application areas prone to fire exposure. The current work addressed this major drawback of epoxy by modifying it with a nanofiller, such as multiwalled carbon nanotubes (MWCNT), and reinforcing it using basalt and sisal fibers. The effect of exposure to elevated temperature on the behavior of concrete cylinders externally confined with these FRP systems was analyzed. Three types of specimens were considered: unconfined; confined with sisal fiber reinforced polymer (SFRP); and confined with hybrid sisal basalt fiber reinforced polymer (HSBFRP) specimens. The test samples were exposed to elevated temperature regimes of 100 °C, 200 °C, 300 °C and 400 °C for a period of 2 h. The compressive strengths of unconfined specimens were compared with various confined specimens, and from the test results, it was evident that the mechanical and thermal durability of the FRP systems was substantially enhanced by MWCNT incorporation. The reduction in the compressive strength of the FRP-confined specimens varied depending on the type of the confinement. After two hours of exposure at 400 °C, the compressive strength corresponding to the epoxy-HSBFRP-confined specimens were improved by 15%, whereas a 50% increase in strength corresponding to MWCNT-incorporated epoxy-HSBFRP-confined specimens was observed with respect to unconfined unexposed specimens. The MWCNT-modified epoxy-incorporated FRP-confined systems demonstrated superior performance even at elevated temperatures in comparison to unconfined specimens at ambient temperatures.

Preparation and Characterization of Cardanol-Based Flame Retardant for Enhancing the Flame Retardancy of Epoxy Adhesives.

Epoxy resin has a versatile set of applications due to its excellent properties. However, its easily flammable property limits further applications. A bio-based flame retardant, cardanyl diphenylphosphate (CDPP), was successfully synthesized via condensation reaction between cardanol and diphenyl phosphoryl chloride. The chemical structure of CDPP was confirmed via 1H nuclear magnetic resonance and Fourier transform infrared spectroscopy. To overcome the flammable property of epoxy resin, different amounts of CDPP were incorporated into the epoxy resin. The thermal stability of epoxy resin with CDPP was reduced due to its phosphorus component, which had a relatively weak bond. Meanwhile, the measured char residue of epoxy resin with CDPP was increased compared to its calculated value, which indicated that CDPP promoted the formation of char residue. The limiting oxygen index of epoxy resin with CDPP was enhanced as the amount of CDPP increased from 22.1% for EP0 to 32.7% for EP10. The maximum value of the heat release rate per unit area and total heat release values of EP10 decreased by 23.23% and 12.02%, respectively, as compared to those of EP0. Additionally, single lap shear strength confirmed the improvement in the adhesion property of EP5. The lap shear strength increased to 7.19 MPa for EP5 compared to 6.27 MPa for EP0. This behavior might be due to the higher polarity of the phosphorus components. Based on the findings gathered in the present study, the incorporation of a bio-based flame retardant (CDPP) in epoxy resin has the potential for improving flame retardancy and adhesion property, which will be promising for the industrial area.

Preparation of an organometallic complex based on phosphonitrile and its flame retardant application in epoxy resin

An organo-cobalt coordination complex (Co-H4APD), based on phosphonitrile-azacycles, was prepared by hydrothermal method. The flame retardancy, smoke suppression and thermal stability of epoxy (EP) composites were investigate by means of limited oxygen index (LOI), cone calorimeter test (CONE) and thermogravimetric analysis (TGA). The flame retardant modes of action of Co-H4APD in EP were confirmed by experiments, such as thermogravimetry-Fourier transform infrared spectroscopy-gas chromatograph/mass spectrometer (TG-FTIR-GC/MS), exploring condense and gas-phase products after composites pyrolysis or combustion. Results revealed that the introduction of 6 wt.% Co-H4APD increased LOI value to 29.8% and effectively suppressed heat/smoke release of EP composites. The synergistic charring effect of Co-H4APD improved the thermal stability and char-forming ability of composites. The char strength may be well-correlated with gas release for EP/Co-H4APD, conducive to form dense and regularly expanded char layer, with more phosphorus-rich graphitic structures and cross-linking structures catalyzed by cobalt ions. This high-quality char layer was regarded as the most critical side in improving the flame retardant and smoke suppression performance of EP composites. The gas-phase function of Co-H4APD should not be overlooked due to releasing phosphorous-based radicals during pyrolysis, exhibiting flame inhibition effect in gas phase. More efficient interactions between phosphazene and cobalt within one molecule unit of Co-H4APD contributed to its more obvious reduction of the combustion and smoke production than those of the physical mixing system of CoO + H4APD.

Effect of a Novel Graphene on the Flame Retardancy and Thermal Degradation Behavior of Epoxy Resin

The effect of graphene modified with a phosphorus and silicon-containing compound (GO-DOPO-V) on the flame retardancy and thermal stability of epoxy resin (EP) was studied by cone calorimetry and thermogravimetric analysis (TGA) in nitrogen. After incorporation of 2 wt% GO-DOPO-V into EP, maximum decreases of 28.8% in peak heat release rate (pHRR) and 15.6% in total heat release (THR) were achieved compared to that of pure EP. It was shown that GO-DOPO-V significantly promoted the formation of an EP tight char layer and the char residue of EP/GO-DOPO-V composite at 600 °C was 13.39 wt%, which was almost twice that of pure EP. Furthermore, the non-isothermal degradation behavior of EP/GO-DOPO-V composites were investigated also in a nitrogen atmosphere. It was found that the addition of GO-DOPO-V changed the degradation behavior of EP composites in the early and middle stages. Both the Kissinger and Flynn–Wall–Ozawa methods revealed that the addition of GO-DOPO-V increased the thermal degradation activation energy of EP, and improved the flame retardancy of the polymer matrix.

Synthesis of a novel type of high‐efficiency boron‐containing Schiff base flame retardant for epoxy resin

AbstractBoron‐containing Schiff base flame retardant ((E)‐2‐([2,4‐dihydroxybenzylidene]amino)ethyl dihydrogen borate (B‐HIBD) was prepared easily and successfully. Thermogravimetric analysis (TGA) showed that when the additive amount was only 3 wt%, the introduction of B‐HIBD significantly improved the thermal stability of epoxy resin (EP) composites. The cone calorimeter test showed that compared with pure EP, the peak of heat release rate (PHRR), total heat release (THR), smoke production rate (SPR)，total smoke production (TSP) ，and the releasing of CO for 3 wt% B‐HIBD/EP reduced by 58.2, 18.3, 65.9, 51.2, and 28.4%, respectively, showing that B‐HIBD could significantly enhance the fire safety of EP composites. This promotion has been embodied not only in the catalysis function of the Schiff base group containing benzene ring but also in borate participating in the carbon‐forming process, promoting the dehydration and carbonization of the EP surface and delaying the transfer of mass and heat in the combustion process, which enhance performance for flame retardant. So it is an efficient strategy to develop a novel type of high‐efficiency boron‐containing Schiff base flame retardant to improve the fire safety for EP.

Aging behaviour of encapsulated assemblies of epoxy resin under accelerated thermal cycling

Epoxy potting materials are inevitably exposed to cyclic temperature environments during use. Under temperature load, thermal stress concentration occurs inside the epoxy encapsulation layer and leads to interface debonding and resin cracking, which eventually leads to the failure of the encapsulated component. In view of this, the effects of thermal cycling on epoxy resin and its encapsulated assemblies were investigated in this work. The surface morphology was characterized by scanning electron microscope (SEM) and atomic force microscope (AFM), the mechanical properties were measured by the Shore hardness tester and universal electronic extensometer, and the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were employed to explore the thermogravimetric and thermal stability of epoxy resin under thermal cycling. The electrical properties of encapsulated assemblies of epoxy resin were measured by broadband dielectric spectroscopy and breakdown voltage. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the changes of the epoxy molecular structure before and after thermal cycling. Based on the aforementioned results and analysis, an aging mechanism of epoxy resin under an alternating thermal cycle was proposed.

PREPARATION OF IRON- REDUCED GRAPHENE OXIDE/ EPOXY RESIN COMPOSITE AND ITS FLAME RETARDANCY AND THERMAL STABILITY

In order to reduce flammability, smoke release and enhance thermal stability of epoxy resin (EP), iron powder is mixed with graphene oxide/ epoxy resin (GO/EP) composite by mechanical blending. The combustion performance of composite material is investigated through limiting oxygen index (LOI), Underwriters Laboratory (UL)-94 test, and cone calorimeter test (CCT). Thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) are also used to explore the mechanism of flame retardancy and smoke suppression. Results show that, with the addition of 0.5% mass fraction of GO and the corresponding iron powder combination (EP3 sample), the LOI value can achieve 32.5% while reaching the UL-94 V0 rating. Compare with EP0, the peaks of heat release rate, smoke production rate, and smoke factor values of EP3 are decreased by 42%, 60%, and 50%, respectively. The char and TG-FTIR data of EP3 reveal that it has a more compact structure, good thermal stability, and produce fewer toxic gases and smoke. Reduction of GO could inhibit the degradation of EP, and iron catalyzes the formation of carbonaceous char on the surface. Thus, the thermal stability and flame retardancy of EP are improved significantly. This study provides a suitable way to prepare graphene/EP composites that contain iron catalyst and can be extended to the industrial manufacture of flame retardant polymer composites. Keywords: iron powder; epoxy resin; graphene oxide; flame retardant; thermal stability

Thermal stability and electromagnetic interference of Epoxy-graphene/hybrid composite materials

Due to rapid growth in technological development and increased use of automated devices have captivated a meteorite surge in electronic pollution, such as electromagnetic interference (EMI), the noise from electronic equipment, and radiofrequency intrusion, which leads to the malfunction of electronic components. Metals and their alloys can be excellent EMI protecting materials, but their hefty weight, poor corrosion resistance, and cost expenses have restricted their use in this field. The present investigation deals with the preparation of epoxy hybrid nanocomposites. Also, Thermogravimetric analysis (TGA) with a validation study using S-band measurements of EMI shielding effectiveness (SE) of the prepared composites. The result displays an increase in thermal stability of epoxy with 0.5 wt% graphene further points to an increase in thermal stability by adding conducting polymer to it. An epoxy with 0.5 wt% graphene exhibits better microwave absorption, and also the addition of conducting polymer to it increases the absorption quality.

Synergistic improvement of mechanical and thermal properties in epoxy composites via polyimide microspheres

AbstractAchieving synergetic improvements of mechanical strength, toughness, and thermal stability of epoxy resin has been a crucial but very challenging issue. Herein, to explore a new solution for circumventing this issue, polyimide microspheres were successfully prepared through the inverse nonaqueous emulsion process, and the structure, size distribution and morphologies of polyimide (PI) microspheres were comprehensively investigated. Then the PI microspheres were incorporated in epoxy resin matrix to systematically investigate the mechanical and thermal properties of obtained epoxy/PI microspheres composites. It was found that the PI microspheres can not only enhance the mechanical strength of epoxy resin, but also significantly improve the toughness. Specially, the epoxy‐based composites containing 3 wt% PI microspheres exhibit a 47% increase in tensile strength, while the GIC and Charpy impact strength increase by 106% and 200%, respectively. The toughing mechanism of epoxy/PI microspheres composites was discussed. Moreover, the PI microspheres can also endow the epoxy resin with excellent thermal stability and heat resistance. Thus, this work may open a new opportunity to synergistically enhance the mechanical and thermal properties of epoxy‐based composites and may also give some valuable inspiration for the rational design of other high‐performance thermosetting composites.

Remarkable enhancement of thermal stability of epoxy resin through the incorporation of mesoporous silica micro-filler

For the first time, we incorporated mesoporous micro-silica (5 μm, pore size = 50 nm) as a filler in epoxy resin aiming to enter polymer into the pore of the silica. As expected, the thermal stability of the composite increased remarkably, followed by noteworthy thermal degradation kinetics when compared to the controlled cured epoxy resin. Composites were prepared by the direct dispersion of modified nano-silica, modified mesoporous micro-silica, unmodified mesoporous micro-silica, non-porous micro-silica, and irregular micro-silica of various pore sizes as fillers in diglycidyl ether of bisphenol-A epoxy resin via ultra-sonication and shear mixing, followed by oven-curing with 4,4-diaminodiphenyl sulfone. DSC and TGA analyses demonstrated a higher glass transition temperature (increased by 3.65–5.75 °C) and very high activation energy for thermal degradation (average increase = 46.2%) was obtained for the same unmodified silica composite compared to pure epoxy, respectively.

The effects of DOPO modified Co-based metalorganic framework on flame retardancy, stiffness and thermal stability of epoxy resin.

In this work, the effect of a modified metal organic framework material on the fire resistance and mechanical properties of epoxy resin (EP) has been explored. The cobalt based metal organic framework (ZIF-67) was synthesized from an organic ligand with a Schiff base structure. Then DOPO@ZIF-67 was synthesized by modifying ZIF-67 with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), and its effect on EP modification was explored. Compared with the pure EP, 4% DOPO@ZIF-67/EP passed the UL94 V-0 level and the ultimate oxygen index (LOI) reached 32.1%. The SEM pictures of carbon residue indicated that DOPO@ZIF-67 formed a more continuous and dense microstructure, which can enhance the thermal barrier and the physical barrier effect. The addition of DOPO@ZIF-67 also can effectively improve the stiffness and damping coefficient of EP composite material. The porous skeleton structure of DOPO@ZIF-67 can endow EP with rigidity and flame-retardant properties. Furthermore, the existence of DOPO made the combination of ZIF-67 with EP better. The results of this study suggest that DOPO@ZIF-67 may be a good additive for modification of the properties of epoxy thermosetting materials.

Analysis of the behavior of epoxy composites with carbon nano additives under the influence of high temperatures on fires

The results of research on the thermal stability of epoxy resins modified with carbon nanomaterial as polymer composites matrices are presented. It is shown that modification of binder component of composite materials at deposition of carbon nanomaterials leads to improvement of thermal stability, including decrease of intensity of crystal lattice destruction, decrease of amplitude value of thermal effect, increase of duration of oxidation of material at high temperatures, promotes stable formation of heat-protective and insulating carbonized layer.

Wear and thermal resistance properties of aluminium particulate microcomposites

Wear resistance and thermal stability are not fundamental properties of materials, but their effects are inevitable in applications involving two-body contact because of friction-induced wear and heat. Wear resistance and thermal stability of epoxy containing 10% by weight of 66.34 μm aluminium particles were examined using mass loss per sliding distance approach and glass transition temperature (Tg) was used as a parameter for thermal stability. The results obtained revealed a reduction in the wear rate due to addition of aluminium particles. About 62, 58 and 39% reductions at 9 N/0.65 m s−1; 9 N/1.3 m s−1 and 25 N/1.3 m s−1, respectively imply that both sliding speed (v) and the applied load (F) contribute to an increase in the wear rate. A lower coefficient of friction of epoxy aluminium composites signifies lower surface wear rate in comparison with that of the epoxy polymer upon contact with another body in applications. The linear model establishes that v with a P value of 0.0046 has a greater significant influence on the wear resistance of the composite than F with a higher P value (0.0103). By the model, the epoxy aluminium composite under 24.63 N is expected to experience a wear rate of 0.000537 g m−1 which is 1380% lower than that established by the results of the experiment. About 36% increase in Tg is observed and 2FI model affirms that there is a gradual increase in Tg with heat flow through the sample during the glass transition period. Hence, the 2FI model having adequate precision of 164 > 4 is appropriate to be used for navigating a design phase for thermal stability properties.