Evaluation of decomposition kinetics of poly (ether-ether-ketone) by thermogravimetric analysis

Abstract

The non-isothermal thermogravimetric methods have been used extensively for the determination of kinetic parameters in polymers. The poly (ether ketones) are used as matrix in advanced high performance composites due its high thermal stability, excellent environmental performance and superior mechanical properties. In this work, the non-isothermal decomposition kinetics of the polymer poly (ether ether ketone) (PEEK) was evaluated in nitrogen and synthetic air atmospheres, using the Flynn-Wall-Ozawa and Coats Redfern models. The results showed that the necessary time for the material decomposes in 5% is approximately 216 years if it is submitted to temperatures of 350 °C in nitrogen atmosphere. On the other hand, if the material is submitted to air atmosphere, this decomposition time drops to about 1,05 years in the same temperature and for the same conversion rate. The decomposition kinetics study by Coats Redfern showed that the D3 mechanism (three-dimensional diffusion (Jander equation)) had better adjustment to the decomposition kinetics of the material in nitrogen atmosphere, while in synthetic air the R1 mechanism (phase boundary controlled reaction (one-dimensional movement)) has better adjustment to the decomposition kinetics of the material.

Chemical and Thermal Evaluation of Commercial and Medical Grade PEEK Sterilization by Ethylene Oxide

“…For amorphous PEEK crystallization occurs at temperatures approaching Tg (~ 143ºC) but still far below the main crystalline melt transition at 335°C. For industrial applications, which can expose PEEK to continuous temperatures of up to 250°C, operating near or above Tg can induce in-service crystallization 14 . Ethylene oxide gas diffuses through the samples amorphous segments.…”

“…The literature has reported that poly (ether ether ketone) (PEEK) shows excellent mechanical and chemical resistance 12,13 as well as physical properties at high temperatures 14 , it is inert and biocompatible, including its composites, that show improved mechanical properties 15,16 . In this context, this study aims at performing sterilization of PEEK samples, for both medical and commercial grades using ethylene oxide and monitoring the sterilized parts for residues of ethylene oxide by means of thermogravimetry (TGA).…”

Thermal and kinetic analysis of pure and contaminated ionic liquid: 1-butyl-2.3-dimethylimidazolium chloride (BDMIMCl)

“…In decomposition kinetic studies, various researchers have used both iso--conventional and discrimination methods, as per their fi ndings by comparing the activation energies, it is quite justifi ed to use either Flynn-Wall-Ozowa (FWO) or Coats Redfern (CR) models to estimate the kinetic mechanism of different materials by thermal degradation [19][20][21][22][23] . In non-isothermal kinetic studies, the relation for linear temperature increase with time is given as follows: T = T o + βt (1) Where β is the constant heating rate, T o is the initial temperature and t is the time.…”

Structural and Thermo-mechanical Evaluation of Two Engineering Thermoplastic Polymers in Contact with Ethanol Fuel from Sugarcane

“…It has high glass transition (T g ≈ 145 °C) and melting (T m = 340 °C) temperatures and has been discussed in the literature since the 1980s 6,[11][12][13][14][15][16] . It can be subjected to a variety of processing routes, has high chemical resistance to many solvents and is employed in a variety of engineering applications (e.g., aerospace, automotive and chemical industries) [17][18][19][20][21][22] . Polyamide 11 (or PA-11) is another high performance, thermoplastic and semi-crystalline engineering polymer that is widely used in industry and has a lower cost than PEEK.…”