scholarly journals Thermal properties of flax fiber scoured by different methods

2015 ◽  
Vol 19 (3) ◽  
pp. 939-945 ◽  
Author(s):  
Dong Zheng ◽  
Ruo-Yao Ding ◽  
Zheng Lei ◽  
Zhang Xingqun ◽  
Yu Chong-Wen
Keyword(s):  
Thermal Properties ◽  
Thermal Behavior ◽  
Value Added ◽  
Exothermic Peak ◽  
Endothermic Peak ◽  
Scanning Calorimetry ◽  
Volatile Products ◽  
Third Stage ◽  
Thermal Stability Of ◽  
Thermal Gravity Analyzer

Thermal properties of flax roves untreated and treated were characterized by differential scanning calorimetry (DSC) and thermal gravity analyzer (TGA) in order to understand their thermal behavior in more detail and to evaluate the effect of scouring processing on the thermal behavior. Flax roves were treated with six kinds of methods including biological scouring, one bath, two bath, bleaching, alkali scouring and industry chemical scouring as standards. Results showed that all treatments improved thermal stability of flax roves. The results indicated that glass transition temperature (Tg) decreased after scouring besides the sample by directly bleaching. It is more difficult to determine the endothermic peak of flax treated by chemical scouring in industry because it takes a very flat course. A distinct endothermic peak was observed for the untreated flax rove, while a distinct exothermic peak in different temperature interval was revealed for other four treated flax rove samples. For TGA analysis, thermal degradation of flax roves studied consists of three regions of the initial, main, and char decomposition, and the third stage consists of secondary weight loss and carbonization for flax roves with biological scouring, one-bath and two-bath. Besides, different residue left indicates that the bio-scoured flax roves are lost with volatile products and does not contribute to char formation. These results provide valuable preferences for mechanism and top value added application of bio-scouring in flax roves.

Influence of the Annealing on the Thermal Stability of Ge-Sb-Te Materials for Recording Devices

2010 ◽  
Vol 67 ◽  
pp. 22-27 ◽  
Author(s):  
Sergey Kozyukhin ◽  
Alexey A. Sherchenkov
Keyword(s):  
Thermal Properties ◽  
Phase Change ◽  
Phase Change Memory ◽  
Endothermic Peak ◽  
Scanning Calorimetry ◽  
Reading Processes ◽  
Stability Of Structure ◽  
Data Reading ◽  
Thermal Stability Of ◽  
Change Memory

Phase change memory materials of Ge-Sb-Te system [(GeTe)m(Sb2Te3)n (m : n = 1:1; 1:2; 2:1)] were studied during thermal cycling by differential scanning calorimetry, and thermal properties were determined. Reproducible endothermic peak in the range of 390-415°C was revealed in Ge2Sb2Te5, GeSb2Te4, GeSb4Te7, which may possibly influence on the kinetics and endurance of data reading processes in phase-change memory devices. The nature of this endothermic peak is discussed. It was shown that additional annealing of synthesized Ge2Sb2Te5 increase stability of structure and thermal properties of the material.

Mechanical and thermal characterization of grafted PP-NCC nanocomposites

2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik
Keyword(s):  
Thermal Properties ◽  
Interfacial Adhesion ◽  
Thermal Characterization ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Twin Screw ◽  
Thermal Stability Of

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.

Identification of Amber and the Copal under Heat Pressurized Process

2012 ◽  
Vol 554-556 ◽  
pp. 2112-2115
Author(s):  
Hui Li ◽  
Xuan Wang ◽  
Yong Zhu ◽  
Qin Ren
Keyword(s):  
Chemical Properties ◽  
Peak Position ◽  
Exothermic Peak ◽  
Endothermic Peak ◽  
Scanning Calorimetry ◽  
Natural Resin ◽  
Before And After ◽  
Artificial Heat ◽  
Physical And Chemical ◽  
And Chemical Properties

Amber and copal belong to the natural resin, which are similar and transitional in the physical and chemical properties. The artificial heat-pressurized treatment is contributed to the polymerization of the natural copal, and turns into green, yellow-green and deep orange-yellow copal. It is very difficult to identify amber from the heat- pressurized treatment copal only based on the gemological parameters.The thermal behavior of amber and the copal before and after heat-pressurized treatment were analyzed by means of differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(NMR). The results show that amber exists an evident endothermic peak around 123~132°C, and copal reveals an obvious endothermic peak at about 174~178°C, and the heat pressurized treatment copal occurs a clear exothermic peak around 150~152°C. The differences between endothermic or exothermic transition and peak position reveal occurring thermal oxidation or the bond breaking or the melting, which are of great significance in the identification.

scholarly journals Thermal stability of Sn anode material with non-aqueous electrolytes in sodium-ion batteries

2018 ◽  
Vol 6 (41) ◽  
pp. 20383-20392 ◽  
Author(s):  
Yongho Lee ◽  
Hyojun Lim ◽  
Sang-Ok Kim ◽  
Hyung-Seok Kim ◽  
Ki Jae Kim ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Behavior ◽  
Anode Material ◽  
Sodium Ion ◽  
Aqueous Electrolytes ◽  
Sodium Ion Batteries ◽  
Scanning Calorimetry ◽  
Sn Anode ◽  
Thermal Stability Of

The thermal behavior of fully lithiated and sodiated Sn electrodes cycled in a MePF6 (Me = Li or Na)-based electrolyte was studied using differential scanning calorimetry (DSC).

Epoxy Cured with Anhydride Terminated Polydimethylsiloxane: Cure Kinetics and Thermal Properties

2011 ◽  
Vol 415-417 ◽  
pp. 261-264
Author(s):  
Yuan Ren ◽  
Zheng Xi ◽  
Wen Jun Gan ◽  
Liang Zhang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Properties ◽  
Succinic Anhydride ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
Thermogravimetric Analyses ◽  
Isothermal Measurements ◽  
Thermal Stability Of

A siloxane-containing dianhydride, succinic anhydride terminated polydimethylsiloxane (DMS-Z21) was selected to cure diglycidyl ether of bisphenol-A based epoxy resin (DGEBA). The cure kinetics and thermal properties were investigated by nonisothermal and isothermal differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA), respectively. The activation energy (Ea) of the curing reaction was obtained based on the methods of Kissinger and isothermal measurements. The results of the thermogravimetric analyses of the DGEBA/DMS-Z21 system showed that the thermal stability of the DGEBA/DMS-Z21 system was slightly higher than the DGEBA/MeTHPA system.

scholarly journals Antistatic and Thermal Properties of Poly(Lactic Acid)/Polypropylene/Carbon Nanotube Nanocomposites

2020 ◽  
Vol 16 (2) ◽  
pp. 57-69
Author(s):  
Wen Shyang Chow ◽  
Yuan Ting Lim
Keyword(s):  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Poly Lactic Acid ◽  
Compression Moulding ◽  
Scanning Calorimetry ◽  
Blend Ratio ◽  
Crystallisation Temperature ◽  
Pp Blends ◽  
Thermal Stability Of

The aim of this study is to investigate the influence of carbon nanotubes (CNT) on the antistatic and thermal properties of poly(lactic acid)/polypropylene/carbon nanotubes (PLA/PP/CNT) nanocomposites. PLA/PP (blend ratio = 60:40) containing CNT (loading 1.0 to 2.5 phr) was melt-compounded followed by compression moulding. The antistatic properties of PLA/PP/CNT nanocomposites achieved at 2.5 phr CNT loading. Thermogravimetric analysis (TGA) results indicated that the thermal stability of PLA/PP/ CNT nanocomposite was higher than PLA/PP blend. Differential Scanning Calorimetry (DSC) results demonstrated that CNT reduced the cold crystallisation temperature of PLA, while increased the crystallisation temperature of PP, which evidenced the nucleatingability of CNT in the PLA/PP blends.

scholarly journals Thermal stability of segmented polyurethane elastomers reinforced by clay particles

2009 ◽  
Vol 63 (6) ◽  
pp. 621-628 ◽  
Author(s):  
Jelena Pavlicevic ◽  
Jaroslava Budinski-Simendic ◽  
Mészáros Szécsényi ◽  
Nada Lazic ◽  
Milena Spirkova ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Polyurethane Elastomers ◽  
Oh Groups ◽  
Clay Nanoparticles ◽  
Thermal Stability Of

The aim of this work was to determine the influence of clay nanoparticles on thermal properties of segmented polyurethanes based on hexamethylene- diisocyanate, aliphatic polycarbonate diol and 1,4-butanediol as chain extender. The organically modified particles of montmorillonite and bentonite were used as reinforcing fillers. The structure of elastomeric materials was varied either by diol type or chain extender content. The ratio of OH groups from diol and chain extender (R) was either 1 or 10. Thermal properties of prepared materials were determined using modulated differential scanning calorimetry (MDSC). Thermal stability of obtained elastomers has been studied by simultaneously thermogravimetry coupled with DSC. The glass transition temperature, Tg, of soft segments for all investigated samples was about -33?C. On the basis of DTG results, it was concluded that obtained materials were very stable up to 300?C.

Syntheses of novel benzoxazines having vinyl groups and thermal properties of the thermosets

2012 ◽  
Vol 24 (8) ◽  
pp. 765-774 ◽  
Author(s):  
Tsutomu Takeichi ◽  
Soulideth Thongpradith ◽  
Shoko Hirai ◽  
Tomomi Takiguchi ◽  
Takehiro Kawauchi
Keyword(s):  
Thermal Properties ◽  
Ring Opening ◽  
Exothermic Peak ◽  
Thermal Cure ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Chemical Structures ◽  
Polymerization Behavior ◽  
Chain Polymerization ◽  
Vinyl Group

Novel benzoxazines having vinyl groups were synthesized from phenol or bisphenol A, 3- or 4-vinylaniline and paraformaldehyde. The chemical structures of the monomers were confirmed by Fourier transform infrared and 1H-NMR analyses. The polymerization behavior of the monomers was monitored by differential scanning calorimetry. Exothermic peak of the monomers appeared in the range of 219–252 °C, due to the chain polymerization of the vinyl group and the ring-opening polymerization of benzoxazine occurring at the same temperature range. The thermal cure of the monomers afforded polybenzoxazines that have higher thermal properties than those from typical benzoxazines without vinyl groups. For example, glass transition temperature ( Tg) increased for 40 to 100 °C by the introduction of vinyl groups, the highest Tg being observed at 290 °C. The 5% weight loss temperature determined by thermogravimetric analysis also increased by the introduction of vinyl groups.

scholarly journals Desiccation sensitivity of wild Castanea mollissima Blume determined by differential scanning calorimetry

2020 ◽  
Vol 49 (4) ◽  
pp. 975-980
Author(s):  
Biao Han ◽  
Lu Lu ◽  
Su-Juan Guo ◽  
Wen-Qing Li ◽  
Xiao-Man Xie
Keyword(s):  
Thermal Properties ◽  
Moisture Content ◽  
Water Content ◽  
Exothermic Peak ◽  
Onset Temperature ◽  
Unfrozen Water ◽  
Scanning Calorimetry ◽  
Moisture Contents ◽  
Unfrozen Water Content ◽  
Castanea Mollissima

Thermal properties of wild Castanea mollissima seeds embryos with different moisture contents, and the optimal moisture contents for cryopreservation were studied. Seeds of similar size and weight (3.5 ± 0.3g) were put in silica gel at 0 to 7 days, embryo moisture content, viability and thermal properties were measured everyday. The results showed that the onset temperature and the crystallization peak of the mean enthalpy decreased with the decrease of embryo moisture content. Exothermic peak disappeared when the seeds were dried for 4 days, with an embryo moisture content of 0.45 ± 0.15 gH2O/g dw. The unfrozen water content (WCu) was 0.247 gH2O/g dw. The optimal water content was found to be 0.45 ± 0.15 gH2O/g dw, with the survival of 76.2%. Castanea mollissima embryonic axes dehydration needs comprehensive consideration of exothermic peak, unfrozen water content, onset temperature and viability loss.

Effects of Calcium Carbonate on the Thermal Properties of Acrylonitrile-Butadiene-Styrene/Calcium Carbonate Composites

2013 ◽  
Vol 834-836 ◽  
pp. 276-280
Author(s):  
Xiao Juan Bai ◽  
Ling Wang
Keyword(s):  
Thermal Properties ◽  
Calcium Carbonate ◽  
Loss Rate ◽  
Acrylonitrile Butadiene Styrene ◽  
Mixed Gas ◽  
Scanning Calorimetry ◽  
Weight Loss Rate ◽  
Thermal Stability Of ◽  
Butadiene Styrene ◽  
Maximum Weight Loss

Calcium carbonate (CaCO3) is a filler widely used in plastics. In this study, the effects of CaCO3content and size on the thermal properties of acrylonitrile-butadiene-styrene (ABS)/CaCO3composites were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA results in nitrogen showed that the maximum weight loss rate of the composites gradually decreased with increasing CaCO3content. TGA results in a mixed gas containing oxygen showed that CaCO3addition facilitated the degradation of ABS, and ABS degradation was completed at relatively low temperatures. The effect of nano-CaCO3on the thermal stability of the composites was similar to that of microsized CaCO3.

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