The effect of crystallites on the rheological properties of microphase‐separated PVC‐PBA‐PVC triblock copolymers obtained by single electron transfer‐degenerative chain transfer living radical polymerization

Linear and nonlinear rheological properties of poly(vinyl chloride) (PVC)‐poly(n‐butyl acrylate)‐PVC triblocks of different compositions, obtained by single electron transfer‐degenerative chain transfer living radical polymerization, are investigated, focusing on the effect of crystallites. Dynamic mechanical thermal analysis results show the existence of two glass transition temperatures, denoting microphase segregation. However, rather than phase separation, it is the presence of two types of crystals that melt at T_m1 = 127 ± 0.8°C and T_m2 = 185 ± 2°C, respectively, the factor that determines the rheological response of the copolymers. To the difference with PVC homopolymers, extrusion flow measurements at very low temperatures (T = 100°C) are possible with the copolymers. A change in the viscosity‐temperature dependence is observed below and above the lowest melting temperature. Notwithstanding the microphase separation and the presence of crystallites, experiments carried out in conditions similar to industrial processing reveal a remarkable viscosity reduction for our copolymers with respect to PVC obtained by single electron transfer‐degenerative chain transfer living radical polymerization, conventional PVC, and PVC/[diethyl‐(2‐ethylhexyl) phthalate] compounds. Extrudates free of surface instabilities are obtained at low extrusion temperatures, such as 90–100°C. J. VINYL ADDIT. TECHNOL., 21:24–32, 2015. © 2014 Society of Plastics Engineers     

Synthesis,characterization, and properties of silylene–acetylene preceramic polymers

A series of silylene–acetylene preceramic polymers 3a–e were synthesized by polycondensation reaction of dilithioacetylene with dichlorosilane (H₂SiCl₂) or/and methyldichlorosilane (MeSiHCl₂). Their structures were confirmed by infrared spectra (IR), and ¹H and ²⁹Si NMR spectroscopies. Differential scanning calorimetry (DSC) diagrams show exotherms centered at 200 to 233°C temperature range, attributed to crosslinking reaction of the acetylene and Si? H groups. After thermal treatment, the obtained thermosets 4a–e possess excellent thermal stability. Thermogravimetric analysis (TGA) under nitrogen show the T_d5s (temperature of 5% weight loss) for all the thermosets are above 600°C, and the overall char yields are between 95.62% and 89.67% at 900°C. After pyrolysis at 1200°C, the obtained ceramic residues 5a–e exhibit good thermo‐oxidative stability with final weight retention between 98.76% and 91.66% at 900°C under air. In particular, perhydroploy(silylene)ethynylene 3a , which has the highest Si/C ratio in silylene–acetylene polymers, has the highest char yield, and the derived ceramic material 5a displays the best thermo‐oxidative stability. Based on Scanning electron microscopy and its associated energy‐dispersive X‐ray microanalysis (SEM EDX) and ¹³C magic angle spinning nuclear magnetic resonance (MAS NMR) analysis, ceramic 5a contains the highest SiC content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermai treatment of cold-formed poly(vinyl chloride)

Cold-drawing poly(vinyl chloride) at 24°C increased the yield strength by 25 percent, modulus by 50 percent, and the ultimate strength by 100 percent. The onset of thermal shrinkage was reduced from 80°C (T_g) to 45°C. This thermal instability can be a significant disadvantage of cold-forming for many applications. It is shown in this study that subsequent thermal treatment at 70°C (T < T_g) re-establishes a shrinkage onset temperature of 80°C without reducing property levels. The structural changes associated with both orientation and thermal treatment were investigated using DSC, X-ray diffraction and birefringence. Cold-drawing produces molecular alignment as measured by birefringence and X-ray. Thermal treatment of unstretched samples, as well as stretched samples under constraint and stretched samples unconstrained, always leads to a small reduction in free volume as revealed by a measured increase in enthalpy at T_g. However, this free volume change, produces a thermally-stable oriented structure only when the samples are treated under constraint. Thermal treatment does not stabilize unconstrained samples. Rather it causes almost complete molecular relaxation and a reduction of physical property levels.     

Immobilized laccase on magnetic nanoparticles for enhanced lignin model compounds degradation

As a natural aromatic polymer, lignin has great potential but limited industrial application due to its complex chemical structure. Among strategies for lignin conversion, biodegradation has attracted promising interest recently in term of efficiency, selectivity and mild condition. In order to overcome the issues of poor stability and non-reusability of enzyme in the biodegradation of lignin, this work explored a protocol of immobilized laccase on magnetic nanoparticles(MNPs) with rough surfaces for enhanced lignin model compounds degradation.Scanning electron microscope with energy dispersive spectrometer(SEM-EDS), flourier transformation infrared spectroscopy(FTIR) and thermal gravimetric analysis(TGA) were utilized to characterize the immobilization of laccase. The results showed a maximum activity recovery of 64.7% towards laccase when it was incubated with MNPs and glutaraldehyde(GA) with concentrations of 6 mg·ml~(-1) and 7.5 mg·ml~(-1) for 5 h, respectively. The immobilized laccase showed improved thermal stability and pH tolerance compared with free laccase, and remained more than 80% of its initial activity after 20 days of storage at 4 ℃. In addition, about 40% residual activity of the laccase remained after 8 times cycles. Gas chromatography–mass spectrometry(GC–MS) was utilized to characterize the products of lignin model compound degradation and activation, and the efficiency of immobilized laccase was calculated to be 1–5 times that of free laccase. It was proposed that the synergistic effect between MNPs and laccase displays an important role in the enhancement of stability and activity in lignin model compound biodegradation.     

Direct bio-electrocatalysis by multi-copper oxidases: Gas-diffusion laccase-catalyzed cathodes for biofuel cells

We have studied the bio-electroreduction of oxygen based on direct electron transfer (DET) between laccase and the electrode. Laccase enzymes from two different sources, namely, tree laccase from Rhus vernicifera, and fungal laccase from Trametes hirsuta were used in the study. The gas-diffusion cathode was made using a mixture of teflonized carbon and untreated carbon black, with a nickel mesh that served as a current collector, sandwiched between a hydrophobic gas diffusion layer, and a hydrophilic biocatalytic layer with physically adsorbed laccase enzyme. High current densities: up to 1 mA cm⁻² under oxygen (for bio-electrocatalytic oxygen reduction) and increased stability (up to 30 days) has been achieved using teflonized carbon blacks at gas–electrode interface, high surface area carbon black for loading the enzyme.Gas diffusion laccase-catalyzed cathode demonstrates a number of advantageous properties including good adhesion, biocompatibility and high bio-electrocatalytic properties. An open circuit potential (OCP) of 600 mV at pH 7 for tree laccase (R. vernicifera) and 725 mV at pH 5 for fungal laccase (T. hirsuta) at zero current densities were obtained with respect to SHE reference electrode. Tafel plots obtained confirmed different DET characteristics for the two sources of laccase enzymes, which could suggest different mechanism of charge transfer: 4-electron electroreduction of oxygen using fungal laccase and 2-electron electroreduction using tree laccase. The performance of the cathode was studied in galvanostatic mode and polarization curves at various conditions are reported including those obtained under air and neat oxygen feed from the gas phase.     

Statistical Optimization of Culture Conditions and Characterization for Ligninolytic Enzymes Produced from Rhizopus Sp. Using Prickly Palm Cactus Husk

Dry prickly palm cactus (Nopalea cochenillifera) husk was investigated as a substrate for Rhizopus sp. cultivation in the solid state, aiming at the production of laccase (Lac), lignin peroxidase (LiP), and manganese peroxidase (MnP). The optimization of fermentation was evaluated by an experimental design and it was obtained, for each enzyme, maximum productivities (U g^?1 h^?1) of: 0.085 ± 0.02 (MnP), 0.066 ± 0.001 (LiP), and 0.023 ± 2.3.10^?4 (Lac), at the conditions of 10 g of substrate, 72 h of fermentation, a_w = 0.865, and 30°C. The enzymes thermal and pH stabilities were evaluated and it was observed better results at temperatures no higher than 60°C and pH of 5.0; in addition, the storage of these enzymes was better at ? 25°C than at 4°C. Since the prickly palm cactus is an agricultural substrate and specially because of its low cost, it is important to propose different applications for it as, for example, an alternative substrate for biotechnological processes.     

Phase transformation and microstructure of MgO–Al2O3–SiO2 system glass–ceramics under different heat treatment conditions

Abstract

Effects of heat treatment conditions on phase transformation, microstructure and thermal expansion coefficient (TEC) in MgO–Al₂O₃–SiO₂ system glass–ceramics were investigated by means of differential thermal analysis, X-ray diffraction and scanning electron microscopy. The magnesium aluminium titanate (MAT) precipitated firstly at 850°C and β-quartz solutions (β-QSS) formed at 950°C. Further increasing temperature to 1000°C, MAT disappeared and β-QSS became master phase, following little amount of α-cordierite, MgTi₂O₅, rutile and sapphirine. When glass was treated at 1050°C, β-QSS content decreased and α-cordierite became master phase. As temperature reached higher than 1100°C, β-QSS and sapphirine disappeared, and α-cordierite became master phase accompany with rutile and MgTi₂O₅ as secondary phase. The microstructure transformed gradually from particle shape crystallites to slat shape network with the increase in heat treatment temperature. By controlling heat treatment condition, an ideal glass–ceramics with proper TEC for matching sealing to 4J29 alloy has been obtained.     

Crystalline structure and morphology of poly(L‐lactide) formed under high pressure

The poly(l ‐lactide) (PLLA) samples were prepared by the annealing under 100 MPa at 75–145^°C and 200 MPa at 105–145^°C for 6 h, respectively. The crystalline structures, thermal properties and morphology were investigated using differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), and scanning electron microscopy (SEM). On the basis of the DSC and WAXD results, it can be seen that the α′ form was formed by the annealing under 100 MPa at 85–95°C but not found under 200 MPa at 105–145°C. A phase diagram of PLLA crystal form under high pressure was constructed under the given experimental conditions, which displayed the α′ form was formed at limited temperature and pressure range. Besides, SEM suggested that the PLLA samples annealed under 100 MPa crystallize to form lamellar‐like crystals due to the low growth rate and the confined crystallization behavior under high pressure. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40637.     

Failure mechanism of rigid polyurethane foam under high temperature vibration condition by experimental and finite element method

The failure mechanism of rigid polyurethane foam (RPUF) under room temperature (RT) and high temperature vibration conditions was investigated by experiment and finite element stimulation. Damaged RPUF specimens were prepared at different vibration amplitudes ranging from 0 to 19.879 mm at RT and 150 °C for different vibration times. The tensile test was utilized to evaluate the vibration damage degree of RPUFs, and the results exhibited that tensile strength decreased gradually with the increase of vibration amplitude and time at both RT and 150 °C. Thermogravimetric analysis and Fourier transform infrared spectroscopy illustrated that thermal degradation of RPUF is attributed to the decomposition of carbonyl urethane groups at 150 °C. The scanning electron microscopy analysis of the tensile fracture surfaces revealed that the vibration failure of RPUF mainly resulted from the existence of microcracks in cell structure. A finite element simulation was established by ABAQUS to study stress distribution of RPUF under different vibration loads, which then demonstrated that the microcracks are most likely to exist on the junction of two microcell units, which is due to convergence of stress in the process of vibration. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48343.     

Protein Engineering of the Antitumor Enzyme PpADI for Improved Thermal Resistance

Arginine deiminase (ADI, EC 3.5.3.6) is a potential antitumor drug for the treatment of arginine‐auxotrophic tumors such as hepatocellular carcinomas (HCCs) and melanomas. Studies in human lymphatic leukemia cell lines have confirmed the anti‐angiogenic activity of ADI. Activity and thermal resistance limit the efficacy of ADI in treatment of auxotrophic tumors. Previously, we reengineered ADI from Pseudomonas plecoglossicida (PpADI) for improved activity under physiological conditions (37 °C, PBS buffer, pH 7.4) by two rounds of directed evolution and combination of beneficial substitutions through site‐directed mutagenesis. The best variant, PpADI M6 (K5T/D38H/D44E/A128T/E296K/H404R), showed a 64.7‐fold improvement in k_cat value and a 37.6 % decreased S_0.5 value under physiological conditions. However, M6 lost rapidly its activity (half‐life of ～2 days at 37 °C). Here we report the re‐engineering of PpADI M6 for improved thermal resistance by directed evolution in order to increase its half‐life under physiological conditions. Directed evolution and recombination of the two most beneficial positions yielded variant PpADI M9 (K5T/D38H/D44E/A128T/V140L/E296K/F325L/H404R), for which the T_m value increased from 47 (M6) to 54 °C (M9); this corresponds to an increased half‐life from ～2 days (M6) to ～3.5 days (M9) under physiological conditions. Structure analysis of the homology model of M9 showed that the beneficial substitutions V140L and F325L likely promote the formation of tetrameric PpADI, which has greater thermal resistance than dimeric PpADI.     

Morphological evolution of polytetrafluoroethylene in extreme temperature conditions for aerospace applications

The organic electrical insulator polytetrafluoroethylene (PTFE) is used in aerospace industry under extreme conditions of temperature and electric field. The melting temperature of PTFE is about 327°C and nowadays operating temperature of this kind of insulators can reach about 300°C and up to 350°C for new generations of machines. All thermal, electrical and mechanical operating stresses, especially high temperature and voltage can be factors of ageing acceleration and/or degradation of the insulators that could cause premature failures. Our present work is focused on the organic insulator behavior at high temperature in order to understand the mechanisms of thermal ageing and degradation. The change of morphology of PTFE during the thermal ageing has been studied. Thin films in PTFE were aged by accelerated method under oxidizing environment (air) and severe thermal constraints between 340 and 450°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39841.     

Formation and micro-Raman spectroscopic study of Aurivilius and fluorite-type SrBi2Nb2O9 nanocrystallites obtained using an ‘amorphous citrate’ route

The crystallization of a SrBi₂Nb₂O₉ gel-glass obtained using the amorphous citrate method was studied by micro-Raman scattering, X-ray diffraction, and electron microscopy techniques. A citric acid–ethanolamine gel with the stoichiometric proportion of the metallic cations was prepared as polymeric precursor and calcined to obtain the amorphous complex. Nanocrystallites with a metastable fluorite-type structure nucleate from the amorphous complex below 500 °C, as shown by X-ray scattering and confirmed by electron microscopy. The morphological study by scanning electron microscopy revealed the nucleation of nanocrystals in the glass-like amorphous powder after thermal treatment at 500 °C. Raman features characteristic of the stable Aurivillius nanocrystals can be detected after thermal treatment at 550 °C, while using X-ray diffraction the crystallization of the Bi-layered perovskite phase is observed only after treatment at 625 °C or higher temperatures. Both X-ray and Raman scattering detected single phase nanocrystallites with Aurivillius structure above 650 °C. The distinctive Raman features of the different SrBi₂Nb₂O₉ nanocrystallites and its evolution with thermal treatment is presented.     

Inactivation of Aerosolized Viruses in Continuous Air Flow with Axial Heating

Thermal inactivation of viruses has been studied in relevance to food sterilization, water purification, and other “non-aerosol” applications, in which heat treatment is applied for a relatively long time. No data are available on the inactivation of airborne viruses exposed to dry heat for a short time, although this is relevant to bio-defense and indoor air quality control. In this study, we investigated inactivation of aerosolized MS2 viruses in a continuous air flow chamber with axial heating resulted from exposures during ～ 0.1–1 s. For an airborne virion, the characteristic exposure temperature, T _e , was defined utilizing the air temperature profiles in the chamber. The tests were conducted at two air flow rates, Q, which allowed for establishing different thermal flow regimes and exposure time intervals. The experimentally determined inactivation factor, IF, was subjected to correction to account for the temperature profiles. At T _e up to ～ 90°C (Q = 18 L/min) and up to ～ 140°C (Q = 36 L/min), the loss of viral infectivity was relatively modest (≤ 10). However, IF increased exponentially as T _e rose from ～ 90°C to ～ 160°C (for 18 L/min) or from ～ 140°C to ～ 230°C (for 36 L/min). Under specific thermal exposure conditions (～ 170°C and ～ 250°C, respectively), IF exceeded ～ 2.4 × 10⁴ (～ 99.996% infectivity loss)—the maximum quantifiable in this study. The airborne MS2 virions exposed to hot air for < 1 s were found to have survived much higher temperatures than those subjected to thermal treatment in liquid for minutes or hours. The findings are significant for establishing limitations of the heat-based bioaerosol control methods.     

The influence of cross‐linking reaction on the mechanical and thermal properties of polyarylene ether nitrile

The processing of cross‐linked polyarylene ether nitrile (PEN), which has a triazine rings structure, has been investigated under different reaction times and temperatures. In this study, the PEN films prepared by the tape‐casting formed the thermally stable triazine rings by catalytic cross‐linking reaction gradually, which was characterized by Fourier transform infrared spectroscopy. The chemical cross‐linking reaction occurred as the CN group absorption of PEN at 2221 cm⁻¹ decreased and a new absorption peak, at 1682 cm⁻¹, was observed, and the absorption peak intensity would be progressively larger, with the extension of the processing time. After the formation of cross‐linking networks, the cross‐linking degree and thermal and mechanical properties of the processed films were improved substantially, compared with the untreated films. The film with added ZnCl₂ as the catalyst was more rapidly cross‐linked, and its properties were better than that without catalyst at the same treatment conditions. The glass‐transition temperature (T_g) of PEN films processed at 350°C for 4 h (213.65°C) was higher than that of PEN films before the treatment (161°C), and the tensile strength was also improved significantly. The PEN was processed at 350°C for 2 h, whose initial decomposition temperature increases by about 10°C, compared with that of untreated film, at one time. The rheology behavior of the cross‐linked films was processed on dynamic rheometer to monitor and track the process of polymer cross‐linking reaction. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Mechanical and thermal performances of epoxy resin/graphitic carbon nitride composites

In this paper, a series of graphitic carbon nitride (g-C₃N₄) was synthesized under different thermal oxidation etching temperatures and epoxy/g-C₃N₄ composites were prepared via solution blending. The morphology and structure of g-C₃N₄ were investigated by transmission electron microscope, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The tensile fracture morphology and structure of epoxy resin (EP) composites were demonstrated by scanning electron microscopy and XRD, respectively. Mechanical properties of EP composites were characterized by tensile testing, and the thermal performances were investigated by dynamic mechanical thermal analysis and thermal gravimetric analysis. The results revealed that the active groups on g-C₃N₄ sheets increased under thermal oxidation etching and the C to N ratio of g-C₃N₄ decreased from 0.94 to 0.76 with the increasing etching temperature. Noticeably, the tensile strength of EP composites was enhanced by 58% with the addition of C₃N₄-NS-500 and the thermal properties were also improved significantly, including T_0.5 (the decomposition temperature at the mass loss of 50%) increased by 21.5 °C and glass transition temperature improved by 8 °C. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48598.     

Tribological properties of PTFE‐filled thermoplastic polyimide at high load,velocity, and temperature

The effect of 20 wt% polytetrafluoroethylene (PTFE) fillers on the friction and wear properties of thermoplastic polyimides (TP) are investigated, under dry sliding in line contact against steel under 50 to 200 N, 0.3 to 1.2 m/s, and 60 to 260°C. Besides the lubricating mechanisms of PTFE based on mechanical shear, the thermal and tribophysical interactions in the sliding interface are considered in this research by using thermoanalytical measurements, Raman spectroscopy, and calculating the maximum polymer sliding temperature T*. The effect of hydrolysis of the TP bulk material, causing high friction at 100 to 140°C, is covered by PTFE. A transition at pv‐values 2.2 MPa m/s (T* = 120°C) is due to thermally controlled sliding of PTFE, while a transition at pv‐values 3.2 MPa m/s (T* = 180°C) remains controlled by degradation of the TP bulk material into monomer fractions. The reduced coefficient of friction in the presence of PTFE leads to smaller degradation and orientation of the molecular back‐bone and side‐chains within the TP structure. The formation of a homogeneously mixed transfer film is only observed at 180 to 260°C. The PTFE forms a fibrillar structure during wear at high sliding velocities, while they wear as separate particles at high normal loads. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers     

Ceria‐coated diesel particulate filters for continuous regeneration

The potential of diesel particulate filters wash‐coated with highly dispersed nano‐metric ceria particles for continuous regeneration has been investigated. To this end, catalytic filters were prepared, soot‐loaded (avoiding the formation of the cake layer), and regenerated—under isothermal conditions—at temperature ranging from 200–600°C. Results have shown that catalytic oxidation of soot starts from 300°C and, at all temperatures, the selectivity to CO₂ is higher than 99%. 475°C is the minimum temperature at which the filter is regenerated via catalytic path. At this temperature, the catalytic filter maintains substantially the same performance over repeated cycles of soot loading and regeneration, indicating that the thermal stability of ceria is preserved. This has been further confirmed by comparison between the outcomes obtained from characterization (X‐ray powder diffraction, N₂ adsorption at 77 K, Hg intrusion porosimetry, and scanning electron microscope/energy dispersive X‐ray analysis) of fresh filter and filter subjected to repeated regeneration tests. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3442–3449, 2017     

Preparation of goat milk powder with Lactobacillus casei L61 and antioxidant peptides: optimization of the composite thermal protectants and evaluation of storage stability

Abstract

The Lactobacillus casei L61 has great ability for producing antioxidant peptides. For reducing the mortality of L. casei L61 in spray drying process, the Box-Behnken design (BBD) was adopted to optimize the composite thermal protective agent formula. The results exhibited that the composite thermal protective agent formula of L. casei L61 contained glucose at 6.03% (w/v), skim milk at 18.98?g/L, and glycerol at 12.50?mL/L. Under the optimal conditions, the average survival of L. casei L61 in the fermented goat milk reached 14.58?±?0.72% after heat treatment at 75?°C for 10?min, which was higher than the control (13.14%). The average hydroxyl free radical scavenging activity of L. casei L61 reached 85.09?±?0.98%, which was not significantly different from the predicted value (86.83%). Therefore, the BBD is feasible for optimizing the composite thermal protective agent formula of L. casei L61. Under the optimal conditions with the inlet air temperature of 130?°C and feed rate of 4.5?mL/min, the maximum viable counts and survival rate of L. casei L61 were 7.46?×?10⁸ cfu/g and 23.41?±?1.28%, respectively. More importantly, the storage stability of antioxidative probiotic goat milk powder was predicted by temperature acceleration test. The shelf life of antioxidative probiotic goat milk powder was estimated to be 352?days at 4?°C and 117?days at 25?°C, embodying the great long-term stability. This study provides a technical reference for industrialized production of probiotic goat milk powder.     

Effect of isomerization on thermal behaviour of bisitaconimides

The effect of isomerization of N,N′‐bisitaconimido‐4,4′‐diphenyl ether to the corresponding biscitraconimide on the curing characteristics and thermal stability of cured resins is described. Resins having bisitaconimide:biscitraconimide ratios of 23:77–93:7 were prepared by reacting 4,4′‐diaminodiphenyl ether with itaconic anhydride in solvents of different polarities and under different reaction conditions. Resins containing a higher proportion of citraconimide had a lower melting point (191 vs 208 °C). The curing exotherm was observed immediately after melting in all the resins and exothermic peak temperature reduced with increase in citraconimide content. Resins having a higher proportion of citraconimide on isothermal curing (200 °C, 2 h) and subsequent heating in nitrogen atmosphere degraded at a slightly lower temperature. However, the char yield at 800 °C did not show any systematic dependence on citraconimide content. © 2002 Society of Chemical Industry     

Kinetics of commercial olive oil oxidation: Dynamic differential scanning calorimetry and Rancimat studies

Four samples of olive oil were oxidized under polythermal (dynamic) conditions in the cell of a normal‐pressure differential scanning calorimeter (DSC) and in the Metrohm Rancimat apparatus. The DSC experiments were carried out in an oxygen flow atmosphere using different linearly programmed heating rates in the range of 4–20 °C/min. Through DSC exotherms, the extrapolated onset temperatures were determined and used for the assessment of the thermal‐oxidative stabilities of the samples. Using the Ozawa‐Flynn‐Wall method and the Arrhenius equation, the activation energies (E_a), pre‐exponential factors (Z) and reaction rate constants (k) for oil oxidation under DSC conditions were calculated. The Rancimat measurements of oxidation induction times were carried out under isothermal conditions in an air atmosphere at temperatures from 100 to 140 °C with intervals of 10 °C. Using the Arrhenius‐type correlation between the inverse of the induction times and the absolute temperature of the measurements, E_a, Z, and k for oil oxidation under Rancimat conditions were calculated. The primary kinetic parameters derived from both methods were qualitatively consistent and they help to evaluate the oxidative stabilities of oils at increased temperatures.