Thermal degradation kinetics and lifetime prediction of poly(aryl ether ketone)s containing 2,6-naphthalene moieties

Due to the synergistic effect that occurs between CNTs and alumina, CNT/alumina hybrid-filled epoxy nanocomposites show significant enhancements in tensile properties, flexural properties, and thermal conductivity. This study is an extension of previously reported investigations into CNT/alumina epoxy nanocomposites. A series of epoxy composites with different CNT/alumina loadings were investigated with regard to their thermal-degradation kinetics and lifetime prediction. The thermal-degradation parameters were acquired via thermogravimetric analysis (TGA) in a nitrogen atmosphere. The degradation activation energy was determined using the Flynn–Wall–Ozawa (F-W-O) method for the chosen apparent activation energy. The Ea showed significant differences at α > 0.6, which indicate the role played by the CNT/alumina hybrid filler loading in the degradation behavior. From the calculations, the lifetime prediction at 5% mass loss decreased with an increase in the temperature service of nitrogen. The increase in the CNT/alumina hybrid loading revealed its contribution towards thermal degradation and stability. On average, a higher Ea was attributed to greater loadings of the CNT/alumina hybrid in the composites.

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Thermal characterizations of basalt fiber-reinforced poly(aryl-ether-ketone) biomedical composites

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-020-10506-3 ◽

2021 ◽

Author(s):

A. Queen Alice ◽

A. Arul Jeya Kumar ◽

M. Prakash ◽

I. Ashok Kumar

Keyword(s):

Basalt Fiber ◽

Fiber Reinforced ◽

Aryl Ether ◽

Aryl Ether Ketone ◽

Ether Ketone

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Mild and in situ photo-crosslinking of anthracene-functionalized poly (aryl ether ketone) for enhancing temporal stability of organic NLO materials

Journal of Materials Science ◽

10.1007/s10853-020-05594-3 ◽

2021 ◽

Vol 56 (9) ◽

pp. 5910-5923

Author(s):

Yanxin Tian ◽

Yulin He ◽

Pan Liu ◽

Hui Zhang ◽

Qiuying Zheng ◽

...

Keyword(s):

Temporal Stability ◽

Aryl Ether ◽

Nlo Materials ◽

Aryl Ether Ketone ◽

Ether Ketone

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

Journal of Composite Materials ◽

10.1177/00219983211008202 ◽

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.

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

Molecules ◽

10.3390/molecules26061597 ◽

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.

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Bonding and Thermal Cycling Performances of Two (Poly)Aryl–Ether–Ketone (PAEKs) Materials to an Acrylic Denture Base Resin

Polymers ◽

10.3390/polym13040543 ◽

2021 ◽

Vol 13 (4) ◽

pp. 543 ◽

Cited By ~ 1

Author(s):

Tzu-Yu Peng ◽

Saiji Shimoe ◽

Lih-Jyh Fuh ◽

Chung-Kwei Lin ◽

Dan-Jae Lin ◽

...

Keyword(s):

Surface Roughness ◽

Thermal Cycling ◽

Fatigue Testing ◽

Lower Surface ◽

Aryl Ether ◽

Bonding Performance ◽

Significant Difference ◽

Aryl Ether Ketone ◽

Ether Ketone ◽

Thermal Cycling Fatigue

Poly(aryl–ether–ketone) materials (PAEKs) are gaining interest in everyday dental practices because of their natural properties. This study aims to analyze the bonding performance of PAEKs to a denture acrylic. Testing materials were pretreated by grinding, sandblasting, and priming prior to polymerization with the denture acrylic. The surface morphologies were observed using a scanning electron microscope and the surface roughness was measured using atomic force microscopy. The shear bond strength (SBS) values were determined after 0 and 2500 thermal cycles. The obtained data were analyzed using a paired samples t-test and Tukey’s honestly significant difference (HSD) test (α = 0.05). The surface characteristics of testing materials after different surface pretreatments showed obvious differences. PAEKs showed lower surface roughness values (0.02–0.03 MPa) than Co-Cr (0.16 MPa) and zirconia (0.22 MPa) after priming and sandblasting treatments (p < 0.05). The SBS values of PAEKs (7.60–8.38 MPa) met the clinical requirements suggested by ISO 10477 (5 MPa). Moreover, PAEKs showed significantly lower SBS reductions (p < 0.05) after thermal cycling fatigue testing compared to Co-Cr and zirconia. Bonding performance is essential for denture materials, and our results demonstrated that PAEKs possess good resistance to thermal cycling fatigue, which is an advantage in clinical applications. The results imply that PAEKs are potential alternative materials for the removable of prosthetic frameworks.

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