Non-oxidative thermal degradation of poly(ethylene oxide): kinetic and thermoanalytical study

Pielichowski, Krzysztof; Flejtuch, Kinga

doi:10.1016/j.jaap.2005.01.003

Cited by 131 publications

(91 citation statements)

References 39 publications

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“…The latter value is in agreement with that found for high molecular weight PEO (30-50 kcal/mol) in existing publications. 15,23 However, the clear differences in the Ea for PEO/G and neat PEO in the present study suggest that polymer-graphene interactions favor the cleavage of polymer bonds in pyrolysis conditions. It is known that simple adsorption of brush-like polymers with long side chains on a substrate can induce spontaneous rupture of covalent bonds in the macromolecular backbone.…”

Section: Kinetics Of the Thermal Decomposition Of Peo Adsorbed On Gracontrasting

confidence: 64%

Thermal Stability of Polymers Confined in Graphite Oxide

et al. 2013

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In this study, polymer-graphite oxide (GO) interactions are demonstrated to induce thermal instability in both the polymer and GO phase in conditions of maximum polymer uptake, in which the polymer chains are either intercalated into the GO interlayer or adsorbed on the GO sheets. We investigate the thermal stability of poly(ethylene oxide) (PEO) intercalated in GO (PEO/GO) in detail, using a combination of techniques including X-ray diffraction (XRD), thermogravimetry (TGA) and TGA-Mass Spectroscopy (TGA-MS) in dynamic (nonisothermal) and static (isothermal) modes. Our results show that intercalated PEO decomposes at 160 • C lower than neat PEO, and that GO decomposes at 50 • C lower than pristine GO, due to a synergistic instability between GO and intercalated PEO upon heating. Other hydrophilic polymers-such as poly(vinyl methyl ether) (PVME), poly(vinyl alcohol) (PAA), poly(vinyl pyrrolidone) (PVP) and poly(acrylic acid) (PAA)-forming polymer-adsorbed GO structures are also observed to decompose at noticeably lower temperatures than either pristine GO or their own corresponding neat polymers. Unlike PEO/GO intercalation compounds, the excess of PEO phase in PEO-GO composites decomposes at temperatures close to that of neat PEO, which demonstrates that those polymer chains far from the adsorbing GO surface are not significantly affected by the presence of GO sheets. Furthermore, isothermal TGA data for PEO/GO intercalation compounds with PEO chains from 5 to 2135 monomeric units are well described by an autocatalytic model similar to that we found for pristine GO in a previous study, which suggests that the overall decomposition of PEO/GO is dominated by the reduction and exfoliation of GO. However, when PEO is adsorbed on graphene substrate, which is thermally stable at the studied temperatures, the kinetic mechanisms follow a first-order reaction similar to neat PEO, but the decomposition occurs with a considerably lower activation energy.

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Section: Kinetics Of the Thermal Decomposition Of Peo Adsorbed On Gracontrasting

confidence: 64%

Thermal Stability of Polymers Confined in Graphite Oxide

et al. 2013

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“…5 Ozawa-Flynn-Wall analysis of the thermal degradation of POM and POM/HAp nanocomposites multiple nonlinear regression method was applied according to the procedure described in [18,19]. The most frequently used mathematical models to describe thermal degradation of polymers used in this work are presented in Table 1 [19][20][21][22]. Hence, graphical results of Friedman and OzawaFlynn-Wall analyses are presented in Figs.…”

Section: Resultsmentioning

confidence: 99%

“…5 mg, and each sample has similar cuboid shape taken always from the same place from specimens after injection molding. Measurements were taken in air atmosphere with air flow rate 30 cm 3 Table 1 Kinetic models [19][20][21][22] Model f(a) Symbol…”

Section: Thermogravimetric Analysismentioning

confidence: 99%

The influence of polyoxymethylene molar mass on the oxidative thermal degradation of its nanocomposites with hydroxyapatite

Pielichowska

2015

J Therm Anal Calorim

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In this paper, the influence of mass-average molar mass (M w ) of polyoxymethylene (POM) copolymer on the thermooxidative degradation behavior of its nanocomposites with hydroxyapatite (HAp) is reported. POM copolymers' thermal stability slightly decreases with a decrease in mass-average molar mass. Thermal stability of POM/HAp nanocomposites is lower in comparison with pure POM, and it gets lower with a decrease in massaverage molar mass of POM copolymer. For POM copolymer with the highest molar mass, thermal stability of POM/HAp nanocomposite was ca. 30°C lower than for pure POM. To get a more in-depth insight into the decomposition process, kinetic analysis of POM/HAp nanocomposite thermal degradation process was performed using Friedman, Ozawa-Flynn-Wall and multiple nonlinear regression methods. The best fit for pristine T2, T3 and T4 copolymers with different molar mass of 100768, 74727 and 68377 g mol -1 , respectively, was obtained for onestage degradation mechanism with autocatalysis, while for T2/10 % HAp and T3/10 % it was parallel reaction model with autocatalysis (Bna) and phase-boundary reaction models (R3). For T4/10 % HAp, the best approximation was found for R2-Bna-D3 reaction model. From hyphenated TG-MS and TG-FTIR thermoanalytical studies, it was found that the main degradation product for POM/HAp nanocomposites is formaldehyde and the amount of other degradation products is lower in comparison with nonmodified POM copolymers.

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“…PEO has -CH 3 end group. PEO is semi-crystalline, biocompatible, biodegradable, non-ionic * corresponding author; e-mail: mehtapejderk@gmail.com and water-soluble polymer of considerable industrial significance which finds applications in many different branches of industry [22]. PEO is currently also used in the pharmaceutical industry for applications such as controlled-release, solid-dose matrix systems, transdermal drug delivery systems and mucosal bioadhesives [23].…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characterization of Surfactant-Modified Powder Activated Carbon (SM-PAC) Reinforced Poly (Ethylene Oxide) (PEO) Composites

2016

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Poly (ethylene oxide), PEO, which was used for a wide variety of applications is a flexible, crystalline, thermoplastic, water-soluble and non-ionic polymer. The most of studies on surfactant-modified activated carbon (SM-PAC) have been generally focused on the removal of contaminants. This study aims the preparation of PEO/(SM-PAC) composites, using solution-intercalation method. Firstly activated carbon was modified with cationic surfactant, Cetyltrimethylammonium Bromide (CTAB). Then PEO/(SM-PAC) composites were prepared using solution-intercalation method, with two different (SM-PAC) contents (1.0 and 2.0 wt.%). The characterization of the composites was made by X-ray diffraction (XRD), Fourier Infrared Spectroscopy (FT-IR), thermal analysis and tensile tests. The XRD patterns revealed that 2θ positions of the broad peaks belonging to the composites significantly shift to left compared with those of virgin PEO. The SEM images of the surfactant-modified powdered activated carbon (SM-PAC)/PEO composites prepared with the two different SM-PAC contents show that there is an intensive interaction between the CTA + ions of modified activated carbon surface and the polymer chains. From the tensile tests, it was found that the unmodified powdered activated carbon dispersed into the polymer matrix made the ductile polymer more brittle. However, the tensile and yield strengths of the composite, prepared with modified powdered activated carbon, have decreased, and the strain percent value has significantly increased.

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Non-oxidative thermal degradation of poly(ethylene oxide): kinetic and thermoanalytical study

Cited by 131 publications

References 39 publications

Thermal Stability of Polymers Confined in Graphite Oxide

Thermal Stability of Polymers Confined in Graphite Oxide

The influence of polyoxymethylene molar mass on the oxidative thermal degradation of its nanocomposites with hydroxyapatite

Preparation and Characterization of Surfactant-Modified Powder Activated Carbon (SM-PAC) Reinforced Poly (Ethylene Oxide) (PEO) Composites

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