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Highlights • Thermal properties of apple pomace flours were followed by DSC and TG/DTG. • Glass transition (T g) above storage temperature ensure a prolonged shelf life of apple pomace flour. • Determination of kinetic parameters of apple pomace flour thermal degradation. • Organic samples of apple pomace flour were found to have a higher thermal stability. Abstract Using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) thermal characteristics and degradation kinetic parameters of apple pomace flours (APF1–5), obtained by dehydration of apple pomace (originating from single and mixed apple varieties, grown both organically and conventionally) and ground to particle size below of 300 μm, were determined. Glass transition (T g) close to common storage temperature (21 °C) was ascribed to commercial sample and T g well above it (28–38 °C) to APF1–5. Both values of T g and low water activity (0.2-0.4) prolong APF shelf-life. The kinetic parameters of the thermal degradation process: activation energy (E) in the range from 83 to118 kJ/mol, logarithmic value of pre-exponential factor (ln(A/min−1)) in the range from 20 to 28, and rate constant (k 200) from 0.143 to 0.278 min−1 were calculated. APF samples were grouped according to rate constant (k 200) values of thermal degradation process at baking temperature (200 °C). Organic samples were found to have a higher thermal stability. [ABSTRACT FROM AUTHOR]

Highlights • Binary and ternary lanthanide complexes with N -phenylanthranilic acid and 1,10-phenanthroline were synthesized. • Formation of the complexes was confirmed by FTIR and XRD methods. • Previously unreported thermal behaviour of these compounds was investigated in oxidative and inert atmospheres. • The coupled TG-FITR-MS technique provided information about gaseous products of thermal decomposition. • The antibacterial activity of the obtained compounds were proved. Abstract New binuclear binary and ternary complexes of Sm(III), Eu(III), and Gd(III) ions with N -phenylanthranilic acid and 1,10-phenanthroline were obtained in solid phase and characterized by chemical and elemental analysis, molar conductance, UV–vis and IR spectroscopies as well as thermoanalytical techniques (TG/DTG–DSC coupled with MS and FT-IR). The dilution method was used to examine the antibacterial activity of the synthesized compounds. The spectroscopic studies indicated that the carboxylate group of N -phenylantranilate ligand is involved in the coordination of metal ion both in binary and ternary complexes. Thermal decomposition of the obtained compounds was carried out in air and nitrogen atmosphere. During heating the complexes decompose via intermediate products to the oxide (Ln 2 O 3) in air atmosphere and to the oxide (Ln 2 O 3) or oxide polluted by carbon (Ln 2 O 3 +nC) in nitrogen atmosphere. The dehydration process was discussed in relation to the nature of water present in these compounds. Using coupled TG-FTIR-MS techniques the decomposition pathways of the synthesized compounds were examined. Additionally, gaseous products released during pyrolysis and thermal oxidation of the complexes were identified. All the complexes exhibit marked activity against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and one Gram-positive (Staphylococcus aureus) bacterial strains. The ternary complexes, especially Gd(III) complex in comparison with the binary ones, have enhanced activity against Escherichia coli. Moreover, antibacterial activity of the synthesized compounds with respect to Pseudomonas aeruginosa is comparable to tetracycline and greater than for kanamycin, erythromycin, and ampicillin. [ABSTRACT FROM AUTHOR]

In this study, the effects of sulfonated poly (styrene-divinylbenzene) (SP(St-DVB)) microspheres on the thermal curing of bisphenol A-based benzoxazine (Ba) was studied by preparing resin systems consisting of Ba and SP(St-DVB) microspheres. The thermal curing behavior and mechanism of Ba/SP(St-DVB) systems were investigated by differential scanning calorimetry and in situ Fourier transform infrared spectroscopy. The curing kinetics of Ba and Ba/SP(St-DVB) systems were investigated by non-isothermal DSC. The apparent activation energy of Ba and Ba/SP(St-DVB) systems gradually increased with the reaction extent (α). The dynamic mechanical analysis indicated that the glass transition temperatures of PBa/SP(St-DVB) composites did not decrease. The improved thermal stability of PBa/SP(St-DVB) composites was investigated by thermogravimetric analysis in the air and nitrogen atmosphere, respectively. The images of the fracture surfaces for PBa and PBa/SP(St-DVB) composites were investigated by scanning electron microscopy, demonstrating improved toughness of PBa/SP(St-DVB) composites. [ABSTRACT FROM AUTHOR]

In this study, novel nanowebs provided with thermal buffering properties were developed via coaxial electrospinning. Environmental friendly and nontoxic dialkyl and dialkenyl carbonates (DACs), namely, didecyl carbonate, didodecyl carbonate, ditetradecyl carbonate, dihexadecyl carbonate, dioctadecyl carbonate and dioleyl carbonate were synthesized from their fatty alcohols based on carbonate interchange reaction. Then the DAC-PMEA nanowebs were produced using 10–50 w% DAC in 3:1 chloroform-ethanol solution as core and 15 w% poly(methyl ethylacrylate) (PMEA)in ethanol as shell by coaxial electrospinning. The SEM images of the nanowebs presented randomly oriented, ultrafine fibers identified with smooth surfaces, continuous and cylindrical shapes. The nanowebs were able to provide considerable enthalpies (40–100 J g −1 ) during their repeated phase changes, up to hundred heating-cooling cycles, corresponding to 52–92% efficiencies obtained from electrospinning. These shape stabilized, lightweight DAC-PMEA nanowebs showed a significant potential for the dynamic thermal insulation applications across various industries, especially for the protection of temperature sensitive materials. [ABSTRACT FROM AUTHOR]

The in-situ fabricated Al 2 O 3 /SiO 2(p) /Al composites were produced by adding different quantities of SiO 2 particles (viz. 0, 3, 6 and 9 wt.%) into molten commercial purity Al at 750 °C. Newtonian thermal analysis was conducted to investigate the solidification behaviors of these molten composites prepared by the stir casting process. The microstructure and phase identification were achieved via optical microscope, SEM (equipped with EDS) and X-ray diffraction. Results showed the dendrite arm spacing of α-Al grain decreased with the increase of SiO 2 addition. The SEM image showed the special duplex phase with Al 2 O 3 layer formed around SiO 2 particle in Al matrix. The Si concentration in Al matrix increased with increasing in the SiO 2 addition, resulting in the decrease of liquidus temperature of the melts. Compared with the purity Al melt, one more stage related to the exothermic Al-Si phase transformation was revealed in the cooling curves of these molten composites. Cooling rate of the purity Al melt was lower than that of the melts with SiO 2 particles addition. The difference in solidification behaviors of these melts was ascribed to the effect of SiO 2 /Al reaction on the effective heat capacity and different amounts of latent heat released from phase transformation process. [ABSTRACT FROM AUTHOR]

The characterization of thermal properties continues to be a challenge facing the development of composite phase change materials. To overcome the practical issues of current techniques a new experimental method was developed. The system is modelled using two fundamental models and a simplified analytical representation. Pure myristic acid is used for validation and a performance comparison based on time, accuracy and stability. All three approaches perform comparatively well in terms of accuracy with an average prediction error of less than one third of a degree and all thermal properties in line with expectations. The enthalpy model is susceptible to instability while the effective heat capacity method does not show any such behaviour. In addition, due to the choice of a smooth function for the transition from liquid to solid, this method delivers more realistic behaviour. The effective heat capacity method is faster than the enthalpy method by a factor of three, but the analytical approach is the fastest. However for a more robust and comprehensive representation the effective heat capacity method is preferred. [ABSTRACT FROM AUTHOR]

Binuclear [Ni 2 (en) 2 (H 2 O) 6 (pyr)]·4H 2 O complex undergoes dehydration in 325–400 K temperature region, which is accompanied by polymerization. Polymerized product is characterized by chelate coordination of carboxylate group to Ni, as identified by vibrational spectroscopy. XRD and spectroscopic measurements suggest that the resulting dehydration product is two-dimensional layered polymer with weak interconnectivity between the polymer layers. A combination of experimental measurements and DFT calculations was used to identify two reaction mechanisms, as well as the factors determining the change from one mechanism to the other. Reaction mechanism changes with increase in the heating rate, due to slow diffusion of released water inhibiting the polymerization. Polymerization occurs in parallel with dehydration at lower heating rates, while it follows dehydration at higher heating rates, leading to an increase in overall enthalpy of the reaction of around 50 kJ mol −1 and decrease in crystallinity of the polymeric product. Determined isokinetic temperature of the dehydration reaction corresponds to the vibrational frequency of Ni OH 2 bond. [ABSTRACT FROM AUTHOR]

A novel amino-containing fluorene-based bisphthalonitrile monomer, 9,9-bis(4-aminophenyl)-2,7-(3,4-dicyanophenoxy)-fluorene (AFPN), was successfully synthesized via the nucleophilic displacement of the nitro-substituent from 4-nitrophthalonitrile. The structure of AFPN was confirmed by Fourier transform infrared (FT-IR), 1 H and 13 C nuclear magnetic resonance (NMR). Its curing behavior and curing kinetics were investigated using differential scanning calorimetry (DSC) and FT-IR techniques. Isoconversional method based on Starink was applied to analyze the curing process of AFPN. The thermal and mechanical properties of the cured product were evaluated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The AFPN showed a self-promoted curing behavior, whereas the introduction of the amino groups increased its curing rate and lowered its curing temperature. Additionally, its cured polymer showed an excellent thermal and thermo-oxidative stability, since its char yield reached 76.5% at 800 °C in nitrogen and 83.4% at 600 °C in air, respectively. [ABSTRACT FROM AUTHOR]

• New adamantane-based dicyanate ester is synthesized. • DSC polymerization kinetics is studied by isoconversional and model based methods. • Polymer is characterized by TGA, TMDSC, and TMA. • Improvement in thermal properties and kinetic changes are linked to structure. A new adamantane-based dicyanate ester has been synthesized. The kinetics of its thermal polymerization is studied by means of conventional and temperature-modulated differential scanning calorimetry. The kinetics is analyzed comprehensively by a combination of an advanced isoconversional and model-fitting method. Polymerization proceeds via transition from a kinetic- to diffusion-control regime, which becomes operative at the later stages of the process. The kinetically-controlled regime manifests itself as a quasi-one-step auto-catalytic reaction. A contribution of diffusion to the overall kinetic is accounted for by means of the Fournier model. The polymerization product possesses excellent thermal properties (the glass transition temperature of ∼370 °C and 5% mass loss temperature of ∼480 °C), which makes it a promising candidate for application in hot-section components for aerospace and military industry. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] Titanium dioxide gel spheres were prepared by sol–gel reaction in O/W emulsion. [•] The effect of atoleine on interior structure of calcined microspheres was exposed. [•] Additive atoleine hindered crystallization of microspheres at below 600°C. [•] The suppressed crystallization by additive atoleine resulted in a solid structure. [ABSTRACT FROM AUTHOR]

Highlights: [•] Physicochemical properties of n-dodecyldimethylammonium picrates were examined. [•] Temperature-dependent infrared spectroscopy detected adiabatic phase transitions. [•] Linear growth of melting and crystallization temperatures with the headgroup number. [•] Higher degree of oligomerization leads to the increased solid phase disorder. [•] The crystal structure of dimeric picrate is determined. [ABSTRACT FROM AUTHOR]

Abstract: Polyacrylonitrile is a thermoplastic polymer with unique properties and it has several uses. However its flammability is a major drawback for certain applications. In this study it was aimed to prepare polyacrylonitrile (PAN)/hexagonal boron nitride (h-BN) composites with improved flame retardancy and thermal stability. Chemical structures of the composites were characterized by FTIR analysis. Thermal properties of these novel composites were analysed by TGA and DSC measurements. Glass transition temperatures and char yields increased with increasing h-BN percentage. Flame retardancy of the PAN composite materials improved with the addition of h-BN and the LOI value reached to 27% from 18%. Furthermore, the surface morphology of the composites was investigated by SEM analysis. [Copyright &y& Elsevier]

Abstract: Microencapsulation of n-octadecane with crosslinked p(butyl methacrylate) (PBMA) and p(butyl acrylate) (PBA) as shells for thermal energy storage was carried out by a suspension-like polymerization. Divinylbenzene (DVB) and pentaerythritol triacrylate (PETA) were employed as crosslinking agents. The surface morphologies of the microencapsulated phase change materials (microPCMs) were studied by scanning electron microscopy (SEM). Thermal properties, thermal reliabilities and thermal stabilities of the as-prepared microPCMs were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The microPCMs prepared by using DVB exhibit greater heat capacities and higher thermal stabilities compared with those prepared by using PETA. The thermal resistant temperature of the microPCM with BMA–DVB polymer was up to 248°C. The phase change temperatures and latent heats of all the as-prepared microcapsules varied little after 1000 thermal cycles. [Copyright &y& Elsevier]

In this paper, we reported the preparation of the bismaleimide-triazine/epoxy interpenetrating polymer networks using 4,4′-bismaleimidodiphenymethane (BMI), bisphenol A dicyanate (BADCy) and 4,5-epoxycyclohexane 1,2-dicarboxylic acid dilycidyl (TDE-85) epoxy resin. The non-isothermal curing kinetics of TDE-85/BMI/BADCy copolymer was studied by the differential scanning calorimetry (DSC) at various heating rates. Kissinger equation and Ozawa equation were used to describe the apparent activation energy of the modified system. Compared to unmodified BMI/BADCy resins, the TDE-85/BMI/BADCy copolymer exhibited excellent mechanical properties and stable thermal properties when the content of TDE-85 epoxy resin was 20wt%. The dielectric properties of TDE-85/BMI/BADCy copolymer such as dielectric constant and dielectric dissipation factor remained the good stability over a wide frequency from 10MHz to 60MHz. [Copyright &y& Elsevier]

Abstract: Crystallization of the new biodegradable polyester poly(butylene azelate) (PBAz) under isothermal and non-isothermal conditions was studied and compared to that of the two homologues, poly(ethylene azelate) (PEAz) and poly(propylene azelate) (PPAz). Among them, poly(butylene azelate) has the faster and easier crystallization, as it was proved by the low supercoolings and lower activation energy needed for nonisothermal crystallization. The enthalpy of melting of the pure crystalline PBAz and the equilibrium melting point were found 36.3kJ/mol and 67.5°C, respectively, compared to 34.2kJ/mol and 62°C for PEAz and 31.9kJ/mol and 72.2 for PPAz. The secondary nucleation theory was applied and crystallization regime transitions I/II and II/III were observed at 30 and 39°C, respectively. Chemical hydrolysis at 30°C shows very slow rates. On the other hand the enzymatic degradation rates of PBAz were comparable to those of poly(ɛ-caprolactone) (PCL) or PEAz. However, PPAz has much faster enzymatic hydrolysis. [Copyright &y& Elsevier]

Abstract: The thermal properties of two conventional polyester-based toners and a chemically prepared styrene/acrylate toner with different thermal histories were studied by scanning probe microscopy (SPM) and differential scanning calorimetry (DSC). The thermal transition temperatures detected by SPM agreed with the results of the DSC measurements. The validity of SPM for detecting thermal transitions was further confirmed by studying two amorphous reference polymers with different glass transition points (T g) and three crystalline reference polymers with different melting points (T m). When the toner sample was heated by the SPM probe above the glass transition temperature of the toner powder (T probe > T g), changes occurred in the surface topography and roughness causing different levels of local sintering of the particles. A set of roughness parameters calculated from the SPM image data were used to quantify the most essential features of toner surfaces. Environmental scanning electron microscopy (ESEM) was used to study the penetration depth of heat dissipated by the SPM probe. The probe-annealing was compared with oven-annealing in order to establish the effect of thermal history on the thermal properties of the materials. [Copyright &y& Elsevier]

Abstract: New mixed-ligand tetraethylammonium halogenocobaltates(II) of general formula [Et4N]2[CoBr n Cl4−n ] have been synthesized. Their thermal properties were characterized on the basis of the TG and DTG curves taken in argon and derivatograms recorded in static air. Some products of successive decomposition steps were identified based on their IR, FIR and VIS spectra as well as the results of elemental analysis. The influence of the nature of the complex anion and oven atmosphere on the progress of thermal decomposition of the compounds has been discussed. [Copyright &y& Elsevier]

Abstract: The thermal properties of the energetic material 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-tetracyclo-[5.5.0.05,9.03,11]-dodecane (HNIW), also known as CL-20, have been investigated by DSC, TG, ARC, HFC and simultaneous TG–DTA–FTIR–MS. The solid–solid phase transitions and the reversibility of these phase transitions were explored using DSC. A heating rate study was performed and the DSC traces show the possibility of a multi-step thermal decomposition of CL-20. The enthalpies of reaction and onset temperatures were determined for various heating rates. The kinetic parameters were found by means of the ASTM E698 method and were verified by ageing experiments. A model-free kinetic (MFK) analysis was performed on the DSC heating rate results. TG experiments were conducted to investigate the effects of various heating rates on the mass loss of CL-20 and its onset temperature. The TG results were analyzed using MFK and ASTM E1641 methods. ARC measurements were performed to investigate the thermal stability of CL-20. The thermal behaviour of CL-20 at various pressures of argon was studied by heat flux calorimetry (HFC). The gaseous products from the decomposition of CL-20 were determined by simultaneous TG–DTA–FTIR–MS experiments in air and in helium. The thermal stability at different isothermal temperatures (190, 195, 200 and 205°C) was studied, using the same technique. [Copyright &y& Elsevier]

Abstract: As a result of solid-state reactions between ZnO and BiVO4, mixed at a molar ratio of 2:1, or among ZnO, V2O5 and Bi2O3, mixed at a molar ratio of 4:1:1, a new double vanadate BiZn2VO6 has been obtained. Its crystallographic system was determined, its unit cell parameters were calculated and its incongruent melting temperature was established. The phase equilibria being established in the system ZnO–BiVO4 over the whole components concentration range up to 1273K were described. [Copyright &y& Elsevier]

Thermal properties differences between rigid rod tetramethyl biphenyl (TMBP) and flexible diglycidyl ethers of bisphenol A (DGEBA) epoxies were studied using modified differential scanning calorimeter (MDSC), thermogravimetric analyzer (TGA) and dynamic mechanical analyzer (DMA) techniques. These epoxies were cured with phthalic anhydride (PA) and phenolic resin (PF5110), respectively. The PF5110-cured epoxy has better thermal properties than the PA-cured epoxy with a higher glass transition temperature (Tg) and a higher decomposition temperature. The good thermal properties of the PF5110-cured epoxy are due to the rigid PF5110 structure on the cured epoxy. DGEBA epoxy has a higher decomposition temperature than the rigid rod epoxy when they are cured with PF5110. But, in the PA curing system, rigid rod epoxy has a better thermal stability. These two different results are due to the different structures of curing agents. [Copyright &y& Elsevier]

The differences of thermal properties between rigid rod and flexible bisphenol A (DGEBA) epoxies were studied using modulated differential scanning calorimeter (MDSC), thermal gravimetric analyzer (TGA) and dynamic mechanical analyzer (DMA) techniques. The rigid rod epoxies of azomethine (AM), biphenol (BP) and tetramethyl biphenol (TMBP) were cured with diaminodiphenylsulfone (DDS) and dicyandiamide (Dicy), respectively. The DDS-cured epoxies have higher glass transition temperature (Tg) and decomposition temperature than the Dicy-cured epoxies due to the high functionality and rigid structure of DDS. The AM, BP and TMBP have higher Tg than DGEBA due to the rigid rod structure. The bulky methyl substitution on the BP main chain of TMBP epoxy decreases the order of polymer packing and reduces the Tg. The AM epoxy has the longest rigid rod structure, thus the AM epoxy has a higher Tg than that of BP and TMBP epoxies. [Copyright &y& Elsevier]

The goal of our study is to develop high refractive index (>1.60) epoxy resin system for optoelectronics and electro-optical equipment assemblies. Molecular design approach is applied to reach this goal by implement of rigid rod moeities or heavy elements (Br) into the epoxy structures. The thermal properties of these new epoxy resins were studied by modulated differential scanning calorimetry (MDSC) and thermogravimetric analyzer (TGA) to investigate the effects of changes of chemical structures. The epoxy resin system containing rigid rod structure exhibits better thermal properties than those containing flexible structure. [Copyright &y& Elsevier]

Zirconium powder is a powerful reducing agent that reacts with oxidizer at elevated temperature, releasing enough heat to ignite pyrotechnic mixtures. In this work, the thermal properties of Zr/KClO4/Viton A priming compositions made by different preparation methods were first investigated using thermal analysis techniques. Then these priming compositions were pressed into the charge holders of pressure cartridges. The firing characteristics of the pressure cartridge were evaluated by using the Bruceton method. The data indicate that the thermal behavior and firing characteristic of Zr/KClO4/Viton A priming compositions were changed because of the different methods of preparation. [Copyright &y& Elsevier]

Abstract: Calcia stabilized zirconia (Ca0.15Zr0.85O1.85) (CSZ) an oxygen ion conducting electrolyte was synthesized from mixed oxalate precursor, namely calcium zirconyl oxalate (CZO). CZO heated in microwave heating system for 1h yielded the stabilized zirconia in the cubic form at 400°C. Same precursor (CZO) heated in resistance heated furnace for 1h yielded pure CSZ at 800°C. Thermogravimetry, differential thermal analysis and X-ray diffraction techniques were used to characterize the precursor and optimize the conditions for microwave processing. BET surface areas of CSZ powders prepared by conventional and microwave heating method at 800 and 400°C are 3.28 and 4.46m2 g−1, respectively. [Copyright &y& Elsevier]

• Zwitterionic copolymers SBVI:MPC were photo-polymerized in I onic L iquid EMI TFSI. • Thermal analysis was used to study interactions of copolymers with water and IL. • Strong zwitterionic-water interactions displace IL causing IL to crystallize. • Water removal causes IL to plasticize the copolymer lowering its glass transition. • Different zwitterionic monomers inhibit formation of physical crosslinks. Understanding the interactions between ionic liquids and polymers is crucial for the design of higher conductivity solid polymer electrolytes. In this work, thermal analysis is used to study the interactions between a hydrophobic ionic liquid, 1-ethyl-3-methylimadazolium bis(trifluoromethylsulfonyl)imide (EMI TFSI), and random zwitterionic copolymers of 2-methacryloyloxyethyl phosphorylcholine (MPC) and sulfobetaine vinylimidazole (SBVI). The zwitterionic copolymers are highly hygroscopic, readily absorbing water from the ambient atmosphere. After absorption, the water displaces EMI TFSI from the zwitterionic groups resulting in crystallization of most of the ionic liquid when cooled to sub ambient temperatures. Upon reheating, absorbed water is removed and the ionic liquid remains in close association with the copolymers. Removal of the water leads to strong interactions between the zwitterions and the ionic liquid, causing plasticization that lowers the glass transition temperature (T g) and inhibits EMI TFSI crystallization. Analysis of the glass transition reveals that the ionic liquid decreases T g significantly below the predicted copolymer T g , and that the copolymer backbone is stabilized by the formation of dipolar crosslinks between zwitterionic side groups of the same species. [ABSTRACT FROM AUTHOR]

• DFR method is proposed to measure the thermal diffusivity of supported nanowires. • This method is with high temporal resolution reach to 100 ps. • The line thermal contact resistance can be obtained with the specific heat known. • A silicon nanowire supported by a sliver substrate has been measured. Precise thermal characterization of supported nanowires is crucial for the thermal analysis in their applications. This paper developed a one-dimension dual-wavelength flash Raman (DFR) method to measure the thermal diffusivity and line thermal contact resistance of an individual supported nanowire. In this method, two laser pulses with different wavelengths are used for heating the sample and probing the Raman spectra, respectively. The temperature variation curves can be captured by changing the time delay between the two pulses, and the temporal resolution can reach to 100 ps. The laser absorption coefficient of the nanowire can be eliminated in the determination of thermal properties, which greatly enhance the measurement accuracy. To the consideration of accuracy and easy operation of the measurement, for different situations, the complete model considered the temperature variation of the substrate and the simplified model ignored the substrate temperature rise were both analyzed. This method has been used to measure a silicon nanowire which is supported by a sliver substrate. Experimental results of the supported silicon nanowire show that the thermal diffusivity of silicon nanowire is (7.3 ± 1.4) ×10−5 m2/s, and the line thermal contact resistance between the nanowire and the substrate is (2.6 ± 0.1) m·K/W. [ABSTRACT FROM AUTHOR]