scholarly journals Post-functionalization of Ether-linked Polymer via the Application of Ullmann-coupling Reaction: Synthesis, Characterization and Thermal Degradation Kinetics

2021 ◽  
Vol 16 (1) ◽  
pp. 21-29
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Degradation Kinetics ◽  
Coupling Reaction ◽  
Degradation Process ◽  
Thermal Degradation Kinetics ◽  
Thermal Stability Of ◽  
Post Functionalization ◽  
Ullmann Coupling

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modification applying the Ullmann-coupling reaction on the C-Br bonds of PE-A, where the bromo-sites have been replaced by aniline-linked moieties.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.

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.

scholarly journals Thermal Stability and Decomposition Mechanism of PLA Nanocomposites with Kraft Lignin and Tannin

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2818
Author(s):  
Nina Maria Ainali ◽  
Evangelia Tarani ◽  
Alexandra Zamboulis ◽  
Klementina Pušnik Črešnar ◽  
Lidija Fras Zemljič ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Food Packaging ◽  
Degradation Kinetics ◽  
Kraft Lignin ◽  
Thermal Degradation Kinetics ◽  
Gas Chromatography Mass Spectrometry ◽  
Poly Lactic Acid ◽  
Pyrolysis Gas ◽  
Thermal Stability Of

Packaging applications cover approximately 40% of the total plastics production, whereas food packaging possesses a high proportion within this context. Due to several environmental concerns, petroleum-based polymers have been shifted to their biobased counterparts. Poly(lactic acid) (PLA) has been proved the most dynamic biobased candidate as a substitute of the conventional polymers. Despite its numerous merits, PLA exhibits some limitations, and thus reinforcing agents are commonly investigated as fillers to ameliorate several characteristics. In the present study, two series of PLA-based nanocomposites filled with biobased kraft-lignin (KL) and tannin (T) in different contents were prepared. A melt–extrusion method was pursued for nanocomposites preparation. The thermal stability of the prepared nanocomposites was examined by Thermogravimetric Analysis, while thermal degradation kinetics was applied to deepen this process. Pyrolysis–Gas Chromatography/Mass Spectrometry was employed to provide more details of the degradation process of PLA filled with the two polyphenolic fillers. It was found that the PLA/lignin nanocomposites show better thermostability than neat PLA, while tannin filler has a small catalytic effect that can reduce the thermal stability of PLA. The calculated Eα value of PLA-T nanocomposite was lower than that of PLA-KL resulting in a substantially higher decomposition rate constant, which accelerate the thermal degradation.

Research on Thermal Degradation Kinetics of Polyphenylene Sulfide Filter Media

2013 ◽  
Vol 300-301 ◽  
pp. 1171-1174 ◽  
Author(s):  
De Qiang Chang ◽  
Jing Xian Liu ◽  
Ning Mao ◽  
Bao Zhi Chen
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Decomposition Temperature ◽  
Polyphenylene Sulfide ◽  
Thermal Degradation Kinetics ◽  
Filter Media ◽  
Initial Decomposition Temperature ◽  
Kinetics Of ◽  
Thermal Stability Of

In order to study the thermal stability of PPS (polyphenylene sulfide) filter media, by means of thermogravimetry(TG), thermal degradation kinetics behavior of two kinds of PPS filter media were analyzed. The kinetic parameters of PPS filter media were obtained according to Flynn-Wall-Ozawa method. Thermal stability of PPS filter media was discussed. It was found that the initial decomposition temperature and activation energy of N3 sample are all higher than B1 sample, the thermal stability of N3 sample is better than B1 sample, and kinetic analysis can be used as an important method to evaluate the thermal stability of filter media.

scholarly journals Fabrication and Thermal Degradation Kinetics of PBT/BEO/Nano-Sb2O3 Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Meng Ma ◽  
Lei Niu ◽  
Jinming Ma ◽  
Jiqiang Ma ◽  
Tifeng Jiao
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Heating Rate ◽  
Thermal Hysteresis ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Polybutylene Terephthalate ◽  
Blending Method ◽  
Kinetics Of

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.

Exploration of Thermal Degradation Kinetics of Epoxy Resin Composites

2021 ◽  
Vol 904 ◽  
pp. 202-206
Author(s):  
Jin Du ◽  
Zheng Huan Wu ◽  
Quan Wang
Keyword(s):  
Thermal Stability ◽  
Boron Nitride ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Hexagonal Boron Nitride ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Flake Graphite ◽  
Kinetics Of

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.

Thermal Properties and Thermal Degradation Kinetics of Polypropylene/ Organomodified Ni-Al Layered Double Hydroxide (LDH) Nanocomposites Prepared by Melt Intercalation Technique

2011 ◽  
Vol 471-472 ◽  
pp. 209-214 ◽  
Author(s):  
Kaberi Kakati ◽  
Aditya Prakash ◽  
G. Pugazhenthi
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Sodium Dodecyl ◽  
Decomposition Temperature ◽  
Thermal Degradation Kinetics ◽  
Precipitation Method ◽  
Melt Intercalation ◽  
Kinetics Of ◽  
Thermal Stability Of

The objective of this work is to investigate the influence of LDH loading on the thermal stability and thermal degradation kinetics of the PP/Ni-Al LDH nanocomposites using thermogravimetric analysis (TGA) and to compare the results with that of the neat PP. For this, Ni-Al LDH was first prepared by co-precipitation method at constant pH using their nitrate salts and subsequently organically modified using sodium dodecyl sulphate (SDS) by regeneration method. A series of novel PP/Ni-Al LDH nanocomposites was then prepared with various amounts of LDH by melt intercalation method. The XRD results confirm the formation of exfoliated PP/LDH nanocomposites. PP/LDH nanocomposites exhibit enhanced thermal stability relative to the neat PP due to the presence of barrier effect of LDH lamellar layers and the thermal stability of the nanocomposites also increases with increase in the LDH loading. When 10% weight loss is selected as a point of comparison, the decomposition temperature of PP/LDH (5 wt %) nanocomposite is 15 oC higher than that of neat PP. The thermal degradation activation energy of the nanocomposites is determined via Coats-Redfern method and compared with that of neat PP. The improvement of thermal stability of PP nanocomposites is also confirmed by increasing the activation energies (Ea) and the integral procedural decomposition temperature (IPDT) compared with neat PP. Criado method is finally used to determine the degradation reaction mechanism of various samples.

Thermal degradation kinetics of Opuntia Ficus Indica flour and talc-filled poly (lactic acid) hybrid biocomposites by TGA analysis

2021 ◽  
pp. 002199832110082
Author(s):  
Azzeddine Gharsallah ◽  
Abdelheq Layachi ◽  
Ali Louaer ◽  
Hamid Satha
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Mechanism ◽  
Melt Processing ◽  
Thermal Degradation Kinetics ◽  
Poly Lactic Acid ◽  
Opuntia Ficus Indica ◽  
Model Free

This paper reports the effect of lignocellulosic flour and talc powder on the thermal degradation behavior of poly (lactic acid) (PLA) by thermogravimetric analysis (TGA). Lignocellulosic flour was obtained by grinding Opuntia Ficus Indica cladodes. PLA/talc/ Opuntia Ficus Indica flour (OFI-F) biocomposites were prepared by melt processing and characterized using Wide-angle X-ray scattering (WAXS) and Scanning Electron Microscope (SEM). The thermal degradation of neat PLA and its biocomposites can be identified quantitatively by solid-state kinetics models. Thermal degradation results on biocomposites compared to neat PLA show that talc particles at 10 wt % into the PLA matrix have a minor impact on the thermal stability of biocomposites. Loading OFI-F and Talc/OFI-F mixture into the PLA matrix results in a decrease in the maximum degradation temperature, which means that the biocomposites have lower thermal stability. The activation energies (Ea) calculated by the Flynn Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS) model-free approaches and by model-fitting (Kissinger method and Coats-Redfern method) are in good agreement with one another. In addition, in this work, the degradation mechanism of biocomposites is proposed using Coats-Redfern and Criado methods.

scholarly journals Thermal Degradation Kinetics and Modeling Study of Ultra High Molecular Weight Polyethylene (UHMWP)/Graphene Nanocomposite

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1597
Author(s):  
Iman Jafari ◽  
Mohamadreza Shakiba ◽  
Fatemeh Khosravi ◽  
Seeram Ramakrishna ◽  
Ehsan Abasi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Thermal Degradation ◽  
High Molecular Weight ◽  
Degradation Kinetics ◽  
Graphene Nanosheets ◽  
Thermal Degradation Kinetics ◽  
Graphene Nanocomposites ◽  
Kinetics Of ◽  
Ultra High Molecular Weight

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.

Thermo-oxidative and thermal degradation kinetics of silica/polymethyl methacrylate composites with electrostatic interaction phase interfaces

2019 ◽  
Vol 39 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Hongyan Li ◽  
Yongqiang Fu ◽  
Hongli Liu ◽  
Cong Sun ◽  
Ruyi Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Polymethyl Methacrylate ◽  
Electrostatic Interaction ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Degradation Kinetic ◽  
Further Development ◽  
Kinetics Of ◽  
Insulation Performance

AbstractThe thermo-oxidative and thermal degradation kinetic parameters of polymethyl methacrylate-methacryloxyethyltrimethyl ammonium chloride/silica aerogel composites (PMMA-MTC/SA) were investigated in this paper and were compared with the thermal stability and thermal conductivity of different types of composites. As a composite with electrostatic interaction, the thermo-oxidative and thermal degradation activation energies (E) of PMMA-MTC/SA were 173.97 and 188.05 kJ/mol, respectively. The results indicated that the electrostatic interaction could indeed enhance the thermal stability of silica/polymethyl methacrylate composites on the premise of good mechanical properties and heat insulation performance. It is of great significance for the further development of silica-based thermal insulation composites.

Characterization and thermal degradation kinetics of thermoplastic polyimide based on BAPP

2017 ◽  
Vol 30 (7) ◽  
pp. 787-793 ◽  
Author(s):  
Xu Su ◽  
Yong Xu ◽  
Linshuang Li ◽  
Chaoran Song
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Step Method ◽  
Nitrogen Derivative ◽  
Degradation Reaction ◽  
Kinetics Of

Two kinds of thermoplastic polyimides (PIs) were synthesized via a two-step method with 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4′-oxydianiline (ODA) diamine, and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and their thermal degradation kinetics was studied by thermogravimetric analysis at different heating rates under nitrogen. Derivative thermogravimetric analysis curves indicated a simple, single-stage degradation process in PI BTDA-BAPP and a two-stage degradation process in PI BTDA-ODA-BAPP. The activation energies ( Eas) of the thermal degradation reaction were determined by the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods without a knowledge of the kinetic reaction mechanism. By comparing the values of Ea and weight loss temperatures, it was demonstrated that the thermal stability of PI BTDA-ODA-BAPP was superior to that of PI BTDA-BAPP.

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