scholarly journals Thermal Degradation of Four Bamboo Species

BioResources ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 414-425 ◽  
Author(s):  
Parnia Zakikhani ◽  
Rizal Zahari ◽  
Mohamed Thariq Hameed Sultan ◽  
Dayang Laila Abang Abdul Majid
Keyword(s):  
Thermal Analysis ◽  
Thermal Degradation ◽  
Nitrogen Atmosphere ◽  
Bamboo Species ◽  
Scanning Calorimetry ◽  
Degradation Behaviour ◽  
Thermal Stabilities ◽  
Higher Temperature ◽  
Dendrocalamus Asper ◽  
Bottom To Top

Bamboo, among other natural plants, has a special structure, with different characterization along the culms and between species. In this study, the thermal stabilities of four bamboo species, named Dendrocalamus pendulus (DP), Dendrocalamus asper (DA), Gigantochloa levis (GL), and Gigantochloa scortechinii (GS), were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) under a nitrogen atmosphere. Each species was divided into three different portions: bottom, middle, and top, and fibres were manually extracted from the specified sections of each species. The thermal analysis of extracted bamboo fibres indicated that the thermal degradation behaviour of each bamboo species varied from bottom to top and between species. However, these variations were lower in DA species compared to GS, GL, and DP, because of minor differences between lignocellulosic components of its three portions. The top and middle portions of the four species degraded at a higher temperature range (314 to 379 °C) than the bottom portions. The results of this study suggest that DA and GS species, according to their thermal stabilities, are most suitable for use as reinforcement in composite materials.

scholarly journals A thermal degradation study of Y and La methanesulfonates

2006 ◽  
Vol 71 (8-9) ◽  
pp. 905-915
Author(s):  
Moura de ◽  
Jivaldo Matos ◽  
Farias de
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Differential Thermal Analysis ◽  
Thermal Degradation ◽  
Degradation Process ◽  
Oxide Formation ◽  
Scanning Calorimetry ◽  
Degradation Study ◽  
Thermogravimetric Data ◽  
Thermal Degradation Process

The synthesis, characterization and thermal degradation of yttrium and lanthanum methanesulfonates is reported. The prepared salts were characterized by elemental analysis and infrared spectroscopy. The thermal degradation study was performed using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC).Using the thermogravimetric data, a kinetic study of the dehydration ofY and Lamethanesulfonates was performed employing the Coats-Redfern and Zsak?methods. It was verified that under heating, yttrium and lanthanum methanesulfonates undergo three main processes: dehydration, thermal degradation and oxide formation. Furthermore, depending on the nature of the atmosphere, i.e., inert or oxidant, the thermal degradation process could be endothermic (N2) or exothermic (air).

Thermal Degradation of Poly(3-hydroxybutyrate) and Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) in Nitrogen and Oxygen Studied by Thermogravimetric–Fourier Transform Infrared Spectroscopy

2007 ◽  
Vol 61 (7) ◽  
pp. 755-764 ◽  
Author(s):  
Christian Vogel ◽  
Shigeaki Morita ◽  
Harumi Sato ◽  
Isao Noda ◽  
Yukihiro Ozaki ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Fourier Transform ◽  
Thermal Degradation ◽  
Degradation Mechanism ◽  
Fourier Transform Infrared ◽  
Nitrogen Atmosphere ◽  
Correlation Spectroscopy ◽  
Ft Ir ◽  
Higher Temperature ◽  
Ir Spectroscopic

The thermal degradation behavior of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate- co-3-hydroxyhexanoate) (P(HB- co-HHx), HHx = 12 mol%) has been studied under different environmental conditions by thermogravimetric analysis (TGA) Fourier transform infrared (FT-IR) spectroscopy. It is reported that at higher temperature (>400 °C) carbon dioxide and propene are formed from the decomposition product crotonic acid in a nitrogen atmosphere, whereas in an oxygen atmosphere propene oxidizes in a further step to carbon dioxide, carbon monoxide and hydrogen. It was also found that PHB and P(HB- co-HHx) have a similar thermal degradation mechanism. The analysis of the FT-IR-spectroscopic data was performed with 2D and perturbation-correlation moving-window 2D (PCMW2D) correlation spectroscopy.

The synthesis, characterization and polymerization kinetic study of a series of related addition polyimides

1994 ◽  
Vol 6 (1) ◽  
pp. 21-34 ◽  
Author(s):  
John M Barton ◽  
Ian Hamerton ◽  
John B Rose ◽  
David Wamer
Keyword(s):  
Thermal Analysis ◽  
Spectroscopic Techniques ◽  
Amino Groups ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Thermally Induced ◽  
Aromatic Residues ◽  
Polymerization Kinetic ◽  
Kinetics Of

A series of eight addition polymides (aspartimides) was prepared in which the imide and amino groups were attached to the ends of aromatic residues containing two or four phenylene rings. The co-monomers (bis-maleimides. BMIs, and diamines) were purified using column chromatography before being fully characterized by spectroscopic techniques. The thermally induced Michael addition and polymerization reactions of the blended co-monomers were monitored using differential scanning calorimetry (Dsc) at several heating rates to enable the kinetics of the processes to be investigated. The thermal stabilities of the thermoset products of these aspartimides were evaluated by thermogravimetric analysis (TGA). Dynamic mechanical thermal analysis (DMTA) was employed to test the physical properties of the neat resins.

scholarly journals Vinyl Ester Resin Modified with Acrylated Epoxidised Soybean (AESO) and Linseed (AELO) Oils: Effect of Additional Urethane Crosslinking

2017 ◽  
Vol 25 (5) ◽  
pp. 363-370
Author(s):  
S. Grishchuk ◽  
J. Karger-Kocsis
Keyword(s):  
Thermal Analysis ◽  
Fracture Toughness ◽  
Thermal Degradation ◽  
Vinyl Ester ◽  
Crosslink Density ◽  
Room Temperature ◽  
Compact Tension ◽  
Vinyl Ester Resin ◽  
Strong Decrease ◽  
Scanning Calorimetry

Bisphenol A-based vinyl ester resin (VE) was modified with acrylated epoxidised soybean and linseed oils (AESO and AELO, respectively) in 10 wt.%. The double bond/epoxy ratio in these functionalised vegetable oils was practically the same, i.e. 30/70%, allowing us to deduce effects caused by the different unsaturations in the parent oils. The crosslink density of the resins was enhanced by adding polyisocyanate. The glass transition temperature (Tg) of the hybrids was determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). Resistance to thermal degradation was assessed by thermogravimetric analysis (TGA). The fracture toughness and energy (Kc and Gc, respectively) were determined on compact tension specimens at room temperature. Incorporation of AESO and AELO reduced the Tg of VE along with slight reductions in the Kc and Gc data. The Tg reduction was less for AELO than AESO which was attributed to the higher functionality of AELO compared to AESO. Urethane crosslinking of VE (VEUH) prominently enhanced the Tg. Modification of VEUH with AES(L)O enhanced the Tg due to additional crosslinks. Urethane hybridisation was associated with a strong decrease in both Kc and Gc compared to those of the parent VE. Kc and Gc of VEUH did not change practically as a function of blending with AES(L)O. Incorporation of AES(L)O reduced the resistance to thermal degradation of both VE and VEUH.

Study on Thermal Degradation Behavior of Composites with Liquid Crystalline Thermoset

2014 ◽  
Vol 1033-1034 ◽  
pp. 927-930
Author(s):  
Hee Jung Moon ◽  
Seung Hyun Cho
Keyword(s):  
Thermal Degradation ◽  
Liquid Crystalline ◽  
Nitrogen Atmosphere ◽  
Degradation Behavior ◽  
Melt Blending ◽  
Scanning Calorimetry ◽  
Thermal Degradation Behavior ◽  
Liquid Crystalline Thermoset ◽  
Weight Loss Process ◽  
Thermosetting Epoxy

Liquid crystalline thermosetting epoxy, 4,4’-Diglycidyloxy-α-methylstilbene (DOMS) was synthesized and characterized with cross-polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Alumina reinforced DOMS composites were fabricated by melt blending with sulfanilamide (SAA) as a curing agent. To investigate thermal degradation behavior, thermogravimetric analysis (TGA) was performed under nitrogen atmosphere at the temperature range from 30 to 1000°C. Activation energies for decomposition (Ed) by TGA were determined as a function of conversion by weight loss process.

Identification of Elastomers by Thermal Analysis

1972 ◽  
Vol 45 (1) ◽  
pp. 329-345 ◽  
Author(s):  
A. K. Sircar ◽  
T. G. Lamond
Keyword(s):  
Molecular Structure ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Chemical Composition ◽  
Thermal Degradation ◽  
Thermooxidative Degradation ◽  
Scanning Calorimetry ◽  
Multiple Peaks ◽  
Thermal Patterns ◽  
Structure Configuration

Abstract Degradation of polymers by thermal and thermooxidative reactions is associated with either evolution or absorption of heat which can be followed by differential scanning calorimetry. In the present investigation, DSC thermographs of elastomers between 0° C and 500° C in nitrogen (thermal degradation) and oxygen (thermooxidative degradation) were used for identification of the elastomers from their degradation patterns. Based on the nature of the thermographs of the raw polymers in nitrogen, the elastomers studied may be divided into the following three main groups: (a) those which show an exotherm, (b) those which show an endotherm, and (c) those which show multiple peaks of endo- or exotherms. Identification is aided in some cases by the thermographs in oxygen as well as by the physical transitions. The nature (exo- or endo-) and shape of the thermal patterns and the temperature domain at which the reactions take place depend on the molecular structure, configuration, chemical composition, and nature of the substituents as well as on the environment. Consequently, thermal and thermooxidative degradation curves may be used as a “fingerprinting” device which can identify many polymers, difficult to identify by other methods.

Thermal stability of phosphorus-containing epoxy resins by thermogravimetric analysis

2018 ◽  
Vol 26 (7) ◽  
pp. 400-407 ◽  
Author(s):  
Xiaomin Lv ◽  
Jialin Fang ◽  
Jinghan Xie ◽  
Xue Yang ◽  
Jiangbo Wang
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Early Stage ◽  
Degradation Process ◽  
Nitrogen Atmosphere ◽  
Thermal Stabilities ◽  
Phosphorus Containing ◽  
Thermal Degradation Process

The thermal stabilities of epoxy resin/diethyl bis(2-hydroxyethyl)aminomethylphosphonate (EP/DBAMP) systems were investigated by thermogravimetric analysis (TGA) under non-isothermal conditions in nitrogen atmosphere. Kissinger and Flynn–Wall–Ozawa methods were used to study the thermal degradation process. The results showed a remarkable increase of activation energy ( E) in the presence of DBAMP, which indicated that the addition of DBAMP retarded the thermal degradation of EP. The Flynn–Wall–Ozawa analysis further revealed that DBAMP significantly increased the activation energy in the early stage of EP’s thermal degradation, demonstrating that DBAMP had improved the initial thermal stability and modified the flame retardancy of EP in the thermal degradation process.

scholarly journals New Coordination Compounds of CuII with Schiff Base Ligands—Crystal Structure, Thermal, and Spectral Investigations

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1004 ◽  
Author(s):  
Dariusz Osypiuk ◽  
Beata Cristóvão ◽  
Agata Bartyzel
Keyword(s):  
Thermal Analysis ◽  
Fourier Transform ◽  
Coordination Compounds ◽  
Simultaneous Thermal Analysis ◽  
Fourier Transform Infrared ◽  
Nitrogen Atmosphere ◽  
Direct Reaction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Organic Part

The new mono-, di- and tetranuclear coordination compounds [Cu(HL1)]·H2O (1), [Cu2(L1)(OAc)(MeOH)]·2H2O·MeOH (2), [Cu4(L2)2(OAc)2]·4MeOH (3), and [Cu4(L2)2(OAc)2]·4H2O·4MeOH (4) were synthesized by the direct reaction of 2,2′-{(2-hydroxypropane-1,3-diyl)bis[nitrilomethylidene]}bis(4-bromo-6-methoxyphenol) (H3L1) or 2,2′-{(2-hydroxypropane-1,3-diyl)bis(nitriloeth-1-yl-1-ylidene)}diphenol (H3L2) and the Cu(II) salt. They were characterized by elemental analysis, X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, simultaneous thermal analysis and differential scanning calorimetry (TG/DSC), and thermal analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR) techniques and the single crystal X-ray diffraction study. In the dinuclear complex 2, the copper(II) ions are bridged by an alkoxo- and a carboxylato bridges. The tetranuclear complexes 3 and 4 are formed from dinuclear species linkage through the phenoxo oxygen atoms of the fully deprotonated H3L2. Compounds 1–4 are stable at room temperature. During heating in air, at first, the solvent molecules (water and/or methanol) are lost and after that, the organic part undergoes defragmentation and combustion. The final decomposition solid product is CuO. The main gaseous products resulting from the thermal degradation of 1–4 in a nitrogen atmosphere were: H2O, MeOH, CH3COOH, CH4, C6H5OH, CO2, CO, and NH3.

A study of the thermodynamics of the crystalline-to-amorphous transformation in Zr-based hydrides by means of thermal analysis

1987 ◽  
Vol 2 (2) ◽  
pp. 173-177 ◽  
Author(s):  
X. L. Yeh ◽  
E. J. Cotts
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Metallic Glasses ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Enthalpy Difference ◽  
Fcc Alloys ◽  
Fcc Phase ◽  
Thermal Stability Of

Amorphous Zr–Rh and Zr–Pd hydrides are prepared both by hydriding metallic glasses and by hydriding metastable, polycrystalline fcc alloys. The thermal stabilities of the amorphous hydrides produced by these two distinct methods are examined by means of differential scanning calorimetry and are found to be similar. The enthalpy difference between the fcc phase and the amorphous phase of Zr81Rh19 is determined to be 0.6 kcal/mol. The thermal stability of Zr–Rh hydrides as a function of hydrogen concentration is investigated.

Thermal Analysis of Chitosan-Lactate and Chitosan-Aluminum Monostearate Composite System

2012 ◽  
Vol 506 ◽  
pp. 278-281 ◽  
Author(s):  
Kotchamon Yodkhum ◽  
T. Phaechamud
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Thermal Degradation ◽  
Chitosan Solution ◽  
Melting Behavior ◽  
Degradation Behavior ◽  
Scanning Calorimetry ◽  
Chitosan Derivatives ◽  
Thermal Degradation Behavior ◽  
Thermal Stability Of

Chitosan possess many attractive properties for applying as biomaterials. For some application, biomaterial devices have to be sterilized using high temperature, e.g. stream sterilizing process. However, thermal degradation behavior of chitosan has been reported previously. Many researchers have attempted to improve thermal degradation behavior of chitosan by synthesize chitosan derivatives or blending chitosan with other polymers or additives. However, chitosan derivatives found to be less thermal stability than chitosan itself. On the contrary, adding some lipid additive could improve thermal stability of chitosan. In this study, protecting effect of aluminum monostearate (Alst) on thermal stability of chitosan was investigated employing thermal analysis techniques, e.g. thermogravimetry (TG), differential scanning calorimetry (DSC) and hot-stage microscope. Lactic acid solution (2% w/v) was used as solvent for dissolving chitosan. Chitosan solution, named as chtiosan-lactate (CL) and chitosan solution contained 2.5% w/w Alst (CLAlst) were prepared and fabricated into sponges using freeze drying technique. Degradation temperature of CLAlst system investigated from TG was shifted to the higher temperature comparing that of CL which indicated that Alst could improve thermal stability of chitosan after processed as biomaterial. From DSC result, small endothermic peak was observed around 60-70°C for CLAlst whereas that of CL did not exhibit any peak. Melting behavior of the sponges observed under hot-stage microscope was demonstrated that chitosan was decomposed whereas Alst dispersed in chitosan backbone was gradually melted.

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