Effect of DFA Modification on Thermal Properties of Multifunctional Epoxy/Anhydride Systems

2017 ◽  
Vol 748 ◽  
pp. 35-38
Author(s):  
Ming Ming Yu ◽  
Lin Fang ◽  
Min Yang ◽  
Hong Li ◽  
Mu Su Ren ◽  
...  
Keyword(s):  
Epoxy Resins ◽  
Dynamic Method ◽  
Degradation Kinetics ◽  
Thermo Gravimetric Analysis ◽  
Thermal Degradation Kinetics ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Thermal Stabilities ◽  
Ozawa Model ◽  
Thermal Stability Of

The thermal stabilities of two amine based multifunctional epoxy resins (TGDDE/MNA & TGBAPP/MNA) and two dimer carboxylic acid (DFA) toughened resins (DFA-TGDDE/MNA & DFA-TGBAPP/MNA) were comparatively investigated with the thermo-gravimetric analysis (TG). The TG parameters of the resins indicated that the thermal stability of the resins was increased after the modification. Furthermore, the thermal degradation kinetics was studied with a dynamic method according to Ozawa model, which explained this phenomenon.

Thermal Stabilities and Mechanical Properties of Two Tetra-Functional Epoxy Resins

2013 ◽  
Vol 284-287 ◽  
pp. 245-249
Author(s):  
Ming Ming Yu ◽  
Yuan Yuan Cui ◽  
Xiao Ma ◽  
Ai Jun Li ◽  
Rui Cheng Bai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resins ◽  
Diphenyl Ether ◽  
Thermo Gravimetric Analysis ◽  
Mechanical Analysis ◽  
Chain Structure ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Thermal Stabilities ◽  
The Relationship

To study the relationship between the molecular main chain structure and the properties of amine based tetra-functional epoxy resins, especially for the thermal stabilities and the mechanical properties, N,N,N',N'-Tetraglycidyl-2,2-Bis[4-(4-aminophenoxy)phenyl]propane (TGBAPP) and N,N,N',N'-Tetraglycidyl-4,4'-diamino diphenyl ether (TGDDE) were cured with Methyl nadic anhydride (MNA). The thermal behavior of the cured epoxy resins were studied with the thermo-gravimetric analysis (TGA), and the glass transition temperature (Tg) were determined with the Dynamic Mechanical Analysis (DMA). Additionally, the mechanical properties of them were tested. The results indicated that the cured epoxy resin based on TGBAPP had better thermal stabilities and toughness.

scholarly journals Development of Nervilia fordii Extract-Loaded Electrospun PVA/PVP Nanocomposite for Antioxidant Packaging

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1728
Author(s):  
Peng Wen ◽  
Teng-Gen Hu ◽  
Yan Wen ◽  
Ke-Er Li ◽  
Wei-Peng Qiu ◽  
...  
Keyword(s):  
Food Packaging ◽  
Thermo Gravimetric Analysis ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Poly Vinyl Alcohol ◽  
Total Phenolic ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Phenolic And Flavonoid ◽  
Thermal Stability Of

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.

Thermal Stabilities and the Thermal Degradation Kinetics Study of the Flame Retardant Epoxy Resins

2014 ◽  
Vol 1053 ◽  
pp. 263-267 ◽  
Author(s):  
Xiu Juan Tian
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Thermal Stabilities ◽  
Degradation Kinetic ◽  
Modified Epoxy

Thermal stability and thermal degradation kinetics of epoxy resins with 2-(Diphenylphosphinyl)-1, 4-benzenediol were investegated by thermogravimetric analysis (TGA) at different heating rates of 5 K/min, 10 K/min, 20 K/min and 40 K/min. The thermal degradation kinetic mechanism and models of the modified epoxy resins were determined by Coast Redfern method.The results showed that epoxy resins modified with the flame retardant had more thermal stability than pure epoxy resin. The solid-state decomposition mechanism of epoxy resin and the modified epoxy resin corresponded to the controlled decelerating ځ˽̈́˰̵̳͂͆ͅ˼˰̴̱̾˰̸̵̈́˰̵̸̳̱̹̽̾̓̽˰̶̳̹̾̈́̿̾̓ͅ˰̶˸ځ˹˰̵̵͇͂˰̃˸́˽ځ˹2/3. The introduction of phosphorus-containing flame retardant reduced thermal degradation rate of epoxy resins in the primary stage, and promote the formation of carbon layer.

Grafting of Chitosan: Structural, Thermal and Antimicrobial Properties

2019 ◽  
Vol 41 (2) ◽  
pp. 240-240
Author(s):  
Nevin Cankaya Nevin Cankaya
Keyword(s):  
Antimicrobial Activity ◽  
Graft Copolymers ◽  
Thermo Gravimetric Analysis ◽  
Antimicrobial Properties ◽  
Gravimetric Analysis ◽  
Analysis Method ◽  
Methacryloyl Chloride ◽  
Thermo Gravimetric ◽  
Thermal Stabilities ◽  
Ft Ir

In this study, some new chitosan materials were synthesized by the grafting of chitosan with the monomers such as 1-vinylimidazole (VIM), methacrylamide (MAm) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). First of all, chitosan methacrylate was prepared by esterification of primary -OH group with methacryloyl chloride a 25.13% yield by mole. The monomers were grafted into chitosan methacrylate via free radical polymerization using 2,2and#39;-Azobisisobutyronitrile as an initiator in N,N-dimethylformamide. The graft copolymers were characterized by FT-IR spectra and elemental analysis. Thermal stabilities of the graft copolymers were determined by TGA (thermo gravimetric analysis) method. The synthesized chitosan methacrylate and its graft copolymers were tested for their antimicrobial activity against bacteria and yeast.

Study on the thermal stability of Controlled Permeability Formwork

2011 ◽  
Vol 374-377 ◽  
pp. 1426-1429
Author(s):  
Xiao Meng Guo ◽  
Jian Qiang Li ◽  
Xian Sen Zeng ◽  
De Dao Hong
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Dynamic Mechanical Analysis ◽  
Thermo Gravimetric Analysis ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
Construction Work ◽  
Thermo Gravimetric ◽  
Excellent Thermal Stability ◽  
Thermal Stability Of

In this study, the thermal properties of a kind of new geotextile materials, so called controlled permeable formwork (CPF), were studied. Thermo-gravimetric analysis showed that the weight of CPF didn’t change much between 0~350 °C. Dynamic mechanical analysis showed that the storage modulus of CPF reduced from 25 MPa to around 10 MPa when the temperature rose to above 100 °C. The strength of sample decreased slightly with the increase of the temperature. The breaking elongation changed slightly with a maximum at 80 °C. The CPF showed excellent thermal stability and was suitable for general use in construction work.

Experimental Investigation of Kevlar KM2Plus Nano-Reinforced Laminated Composite Thermo-Mechanical Properties

2016 ◽  
Author(s):  
Abdel-Hamid I. Mourad ◽  
Omar G. Ayad ◽  
Ashfakur Rahman ◽  
Ali Hilal-Alnaqbi ◽  
Basim I. Abu-Jdayil
Keyword(s):  
Mechanical Properties ◽  
Thermo Gravimetric Analysis ◽  
Laminated Composite ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Three Point Bending ◽  
Multi Walled Carbon Nanotube ◽  
Thermal Stability Of

This work is concerned with the synthesis and characterization of Multi-Walled Carbon Nanotube (MWCNT) reinforced Kevlar KM2Plus composites with various MWCNT contents (0.2, 0.3, 0.4, 0.5, 0.6, and 0.8 wt. %), by the wet lay-up technique. These samples were experimentally investigated for their thermo-mechanical properties using Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), tensile testing and three-point bending techniques. The mechanical properties showed remarkable improvement with increasing MWCNT wt.% up to certain content. The results revealed that the addition of MWCNT fillers has no significant effect on the thermal stability of the composites.

scholarly journals Physicomechanical and Operational Properties Polyurethane Thermal Panels

2020 ◽  
Vol 9 (4) ◽  
pp. 446-454
Keyword(s):  
Ir Spectroscopy ◽  
Uv Radiation ◽  
Thermo Gravimetric Analysis ◽  
Operation Time ◽  
Heat Stability ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Operational Characteristics ◽  
Lower Temperature ◽  
Thermal Stability Of

Evaluation of consumer properties of polyurethane thermal panels is the goal of the work. Physico-mechanical and operational characteristics of thermal panels are determined to achieve the purpose of the work. Methods of IR spectroscopy and thermo gravimetric analysis were used to study the structure of the samples. Satisfactory consumer properties of the studied thermo panels are brought out: compliance of clinker with the DIN EN 121 standard; absence of visual defects and change of color of thermo panels after 50 cycles of freezing-thawing; absence of changing color of thermo panels after influence of UV of radiation with the wavelength of 240-320 nanometers within 607 hours 30 minutes; high values of coefficients of sound absorption in the frequency range from 600 to 1600 Hz; low heat conductivity of the FPU layer. The influence of UV-radiation on thermal stability of foamed polyurethane is valued. Thermal analysis methods and IR spectroscopy are used to assess the degree of UV - destruction of polyurethane foam. At destruction of foamed polyurethane there is a rupture of chemically weak communication and formation of alcohols, air, olefins. The results of IR-spectroscopy illustrate the beginning of the processes of destruction of samples of FPU under the influence of UV-radiation. Using the thermo gravimetric analysis the research of the FPU thermal properties under the influence of UV - radiations is conducted. It is established that compositions from FPU under the influence of UV- radiation have lower temperature of the beginning of decomposition, than initial material. The influence of UV-radiation on heat stability of the studied compositions is shown. The possible mechanism of destruction of FPU is confirmed in the research. The DSС method has estimated the resistance of FPU to the oxidizing influence characterizing the material operation time. The studied consumer properties of thermal panels show that they can be used in civil engineering as effective protection structures of buildings.

CRYSTAL GROWTH, THERMAL, OPTICAL AND MICROHARDNESS STUDIES OF TRIS (THIOUREA) MAGNESIUM SULPHATE: A SEMIORGANIC NLO MATERIAL

2009 ◽  
Vol 23 (25) ◽  
pp. 3035-3043 ◽  
Author(s):  
G. PASUPATHI ◽  
P. PHILOMINATHAN
Keyword(s):  
Magnesium Sulphate ◽  
Second Harmonic ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
Thermal Stabilities ◽  
Growth Technique ◽  
Temperature Solution ◽  
Solution Growth Technique

Single crystals of tris (Thiourea) magnesium sulphate (MTS) were grown from aqueous solution by low temperature solution growth technique. The grown crystals have been characterized by X-ray diffraction to confirm the formation of the crystalline phases. The presence of functional groups was identified by Fourier transform infrared spectroscopy. The optical transmission spectrum showed that a lower cut-off wavelength of MTS crystal is below 300 nm and it has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. The thermal stabilities were studied by differential thermal analysis (DTA) and thermo gravimetric analysis (TGA). Nonlinear optical characteristics of MTS were studied using Q-switched Nd:YAG laser (λ=1064 nm ). The micro-hardness studies reveal the mechanical properties of the grown crystals.

Thermal Degradation and Combustion Performance Comparison of Plywood Based on Inorganic Adhesive and Phenol-Formaldehyde Resin

2017 ◽  
Vol 14 (1) ◽  
pp. 775-779
Author(s):  
Shoulu Yang ◽  
Yiqiang Wu ◽  
Ning Ji ◽  
Yan Qing ◽  
Dan Li ◽  
...  
Keyword(s):  
Phenol Formaldehyde ◽  
Thermo Gravimetric Analysis ◽  
Performance Comparison ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Total Mass Loss ◽  
Thermal Stability Of ◽  
Made In

The main objective of this work was to study a new inorganic adhesive used for wood-based panel. Inorganic adhesive and its poplar plywood were prepared to investigate their properties. Thermo-gravimetric analysis tests revealed that the total mass loss of inorganic adhesive was 76.24%, which was higher than that of phenol-formaldehyde resin (64.97%). The results showed better thermal stability of inorganic adhesive. For inorganic adhesive plywood, approximately 30% decrease in peak of heat release rate, 62% in total smoke production and 20% in mean CO2 yield, respectively, were seen compared to the control by cone calorimeter analysis. Scanning electron microscopy imaged wider glue line of inorganic adhesives plywood, which was related to the bonding strength of plywood. Thus the inorganic adhesive of fireproofing made in lab could be better used for plywood processing.

scholarly journals White light emitting dysprosium doped lanthanum oxalate single crystals

2021 ◽  
Vol 2070 (1) ◽  
pp. 012097
Author(s):  
S Vandana ◽  
Cyriac Joseph
Keyword(s):  
Single Crystals ◽  
White Light ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Visible Absorption ◽  
Light Emitting ◽  
X Ray ◽  
Uv Visible ◽  
Thermal Stability Of

Abstract Single crystals of Lanthanum oxalate [La2 (C2O4)3]1OH2O and Dy3+ doped Lanthanum oxalate [La2-xDyx (C2O4)3]10H2O with x=0.1, 0.15, 0.2 were grown by gel method and characterised by X-ray powder diffraction analysis. Thermal stability of sample was investigated by thermo gravimetric analysis. UV-Visible absorption and photo-luminescent studies were also conducted. The emission spectrum on exciting at 271nm and 364 nm were recorded in which Dy3+ ions showed four emission bands at positions 458nm (blue), 478 nm (blue), 572 nm (yellow) and 655 nm (red) corresponding to transitions 4I15/2→ 6H15/2, 4F9/2→ 6H15/2, 4F9/2→ 6H13/2 and 4F9/2→ 6H11/2 respectively. The CIE coordinates, colour purity and CCT values were calculated, and all these parameters show that Dy3+ doped lanthanum oxalate single crystals are suitable candidates for white light emitting applications.

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