Thermal degradation kinetics, mechanical, and flame retardant properties of epoxy-HDPE fabric-clay composite laminates

2014 ◽  
Vol 131 (18) ◽  
pp. n/a-n/a ◽  
Author(s):  
T. Niranjana Prabhu ◽  
T. Demappa
2014 ◽  
Vol 1053 ◽  
pp. 263-267 ◽  
Author(s):  
Xiu Juan Tian

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.


2018 ◽  
Vol 31 (1) ◽  
pp. 86-96 ◽  
Author(s):  
R Vini ◽  
S Thenmozhi ◽  
SC Murugavel

In this study, azomethine polyphosphonates were synthesized by solution polycondensation of phenylphosphonic dichloride with various azomethine diols such as [4-(4-hydroxy phenyl) iminomethyl] phenol, [(4-(4-hydroxy-3-methoxy phenyl) iminomethyl)] phenol and [4-(4-hydroxy-3-ethoxy phenyl) iminomethyl] phenol using triethylamine catalyst at ambient temperature. The structure of the synthesized polymers was confirmed by Fourier transform infrared and 1H-, 13C- and 31P- nuclear magnetic resonance spectroscopic techniques. Thermal properties of the polymers were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry under nitrogen atmosphere. The TGA data showed that the synthesized polyphosphonates produce high char yield at 600°C due to the presence of phosphorous atom in the polymer chain and hence have good flame-retardant properties. One of the synthesized polyphosphonate was blended with commercial diglycidyl ether of bisphenol-A (DGEBA) resin in various weight percentage and cured with commercial curing agent triethylene tetramine (TETA). The polyphosphonates-blended epoxy thermosets have tensile strength in the range of 5–41 MPa and the percentage of elongation at breaks was 4–18. It was found that the incorporation of polyphosphonates into epoxy thermoset decreased the tensile strength from 41 MPa to 5 MPa, whereas the elongation at break value increased with increase in the weight percentage of polyphosphonate. The influence of polyphosphonates on the flame retardancy of blended thermosets was examined by limiting oxygen index (LOI) and vertical burning (UL-94) tests and found that the polymer samples achieved an increased UL-94 rating and the LOI values were in the range of 24–26. Broido and Horowitz–Metzger methods have been used to study the thermal degradation kinetic parameters.


2012 ◽  
Vol 61 (6) ◽  
pp. 926-933 ◽  
Author(s):  
Zahra Derakhshesh ◽  
Manouchehr Khorasani ◽  
Shahin Akhlaghi ◽  
Bahram Keyvani ◽  
Ali Asghar Sabbagh Alvani

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Meng Ma ◽  
Lei Niu ◽  
Jinming Ma ◽  
Jiqiang Ma ◽  
Tifeng Jiao

Developing polybutylene terephthalate (PBT) with high thermal stability and flame-retardant properties is crucial for automotive, biomedical devices, electronics, and other fields. Herein, we focus on a PBT/brominated epoxy resin (BEO)/nano-Sb2O3 composites by a melt-blending method. The effects of heating rate and nano-Sb2O3 content on the thermal stability and thermal degradation kinetics of PBT composites were studied by TG-DSC. With the increasing of heating rate, the thermal hysteresis effect of temperature gradient is produced, which is eliminated when the temperature exceeds 400°C. With the increase of nano-Sb2O3 content, the E a of PBT/BEO/nano-Sb2O3 composites increases at first and then decreases. When the content of nano-Sb2O3 is 3 wt%, the E a of PBT/BEO/nano-Sb2O3 is the highest, which is 66.18 kJ/mol (31.43%) higher than that of neat PBT. Also, the exploration of the thermal degradation kinetics of PBT/BEO/nano-Sb2O3 composites is expected to provide research ideas for new high flame-retardant materials.


2012 ◽  
Vol 550-553 ◽  
pp. 2767-2772
Author(s):  
Xiu Yun Li ◽  
De Tian Liao ◽  
Han Bing Ma ◽  
Kang Lin Xu ◽  
An Bin Tang

An intumescent flame retardant (IFR) system containing phosphorus-silicon (EMPZR) and ammonium polyphosphate (APP) was used to improve the flame retardancy of poly(ethylene-co-vinyl acetate)(EVA). The influence of EMPZR contents on the flame retardance of EVA/EMPZR/APP composites has been studied. It was found that the reasonable mass ratio of EMPZR/APP in EVA/EMPZR/APP composites is 20/20, whose limiting oxygen index (LOI) value was improved from 19.0 for EVA to 28.6, and the burning grading reached to UL-94 V-0. The thermal behavior of EVA and IFR-EVA was investigated by dynamic thermo gravimetric analysis (TGA) at different heating rates and then the thermal degradation activation energies of EVA and IFR-EVA were determined by using Flynn-Wall-Ozawa method. Meanwhile, morphology of the char residue obtained from burning IFR-EVA in LOI test was studied through the scanning electron microscopy SEM observation, the rich compact char layer in which could explain the good flame retardance and the synergistic effect between EMPZR and APP.


2021 ◽  
Vol 904 ◽  
pp. 202-206
Author(s):  
Jin Du ◽  
Zheng Huan Wu ◽  
Quan Wang

The thermal degradation process of epoxy resin/intumescent flame retardant/flake graphite/hexagonal boron nitride (EP/IFR/FGP/h-BN) was analyzed by thermogravimetry. The effects of binary nano flake graphite/hexagonal boron nitride as synergistic flame retardant on the thermal stability. Flynn wall Ozawa method was used to calculate the activation energy of thermal degradation kinetics of EP/IFR/FGP/h-BN. The mechanism functions of the EP/IFR/FGP/h-BN in different reaction stages were determined according to Malek method, and the thermal degradation mechanism of EP/IFR/FGP/h-BN was obtained. The binary nanoFGP/h-BN is helpful to improve the thermal stability of EP.


2021 ◽  
Vol 16 (1) ◽  
pp. 21-29

A new ether-linked polymer (PE-A) was synthesized via the polycondensation of 1,4-dibromo-2,5-difluorobenzene with biphenol (A). The new polymer has shown a good solubility in non-polar solvents, as well as moderate thermal stability (up to 300 °C). The parent PE-A was subjected to post-functionalization modification applying the Ullmann-coupling reaction on the C-Br bonds of PE-A, where the bromo-sites have been replaced by aniline-linked moieties. The resulting polymer (PE-Ani-A) shows slight solubility in several solvents. Its thermal stability was enhanced by 36% when compared with PE-A. To ensure the significant impact of the inclusion of the aniline group on thermal stability, a thermal degradation kinetics study was performed and the Coats-Redfren and Broido theoretical models were applied to explore the degradation process. The calculated activation energy for PE-Ani-A degradation was thereby found to be higher than that of PE-A, which indicates the higher thermal stability of PE-Ani-A. For further insights into the thermal stability of the polymers, the limited oxygen index (LOI), which represents the flame-retardant property of the polymers, was calculated. The results indicate that PE-A is a promising candidate as a flame-retardant polymer (LOI = 46.7), since it has a high bromo-content. On the other hand, PE-Ani-A has a lower LOI although it has a higher thermal stability.


Sign in / Sign up

Export Citation Format

Share Document