Kinetics and mechanisms of the low-temperature degradation of cellulose

Emsley, Alan; Stevens, G.C.

doi:10.1007/bf00818797

Cited by 297 publications

(212 citation statements)

References 44 publications

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“…At about 140 °C , the rate of the degradation process increases significantly, implying either a change in the activation energy or in the pre-exponential factor [25]. The DP of paper samples aged at 150 °C was significantly decreased due to thermal stress at high temperature, in which the weak links existing in polymer chains are easily chopped [3,9,26,27]. Figure 3 shows the time dependence of TS under accelerated thermal aging at the temperatures of 120 °C and 150 °C .…”

Section: Degree Of Polymerization (Dp) and Tensile Strength (Ts)mentioning

confidence: 99%

Study on the Effects of Thermal Aging on Insulating Paper for High Voltage Transformer Composite with Natural Ester from Palm Oil Using Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-ray Spectroscopy (EDS)

Munajad

Subroto

Suwarno³

2017

Energies

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Abstract:Mineral oil is widely used as liquid insulation in high voltage equipment. Due to environmental considerations, recently natural esters have been considered as naturally friendly liquid insulation candidates for high voltage transformers. In this experiment, transformer insulation paper was subjected to get accelerated aging test with copper strip in natural ester in a hermeneutical heat-resistant glass bottle at temperatures of 120 • C and 150 • C for 336 h, 672 h and 1008 h. The experimental results of Fourier transform infrared spectroscopy (FTIR) showed that the intensity of the absorbance peak of the O-H functional group decreased with aging, while the intensity of the C-H and C=O functional group absorbance peaks have increased with aging and the intensity of the C-O functional group absorbance peak has a tendency to increase with aging. The energy dispersive X-ray spectroscopy (EDS) experimental results showed that the weight percent of the element C increased with aging and the weight percent of the element O has decreased with aging. The experimental results show a good correlation between the degree of polymerization (DP) and the weight percent of O element. This indicates that EDS may be used as a new method for estimating the DP of transformer insulation paper.

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Section: Degree Of Polymerization (Dp) and Tensile Strength (Ts)mentioning

confidence: 99%

Study on the Effects of Thermal Aging on Insulating Paper for High Voltage Transformer Composite with Natural Ester from Palm Oil Using Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-ray Spectroscopy (EDS)

Munajad

Subroto

Suwarno³

2017

Energies

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“…A variety of VOCs are known to be emitted from paper and other cellulose-based materials during degradation (Emsley and Stevens, 1994;Lattuati-Derieux et al, 2004;Lattuati-Derieux et al, 2006;Dupont et al, 2007;Strlič et al, 2007;Ramalho et al, 2009). The resulting VOC emission patterns are known to be complex (Strlič and Kolar, 2008), however, a number of volatile organic compounds were recently identified as specific degradation markers using material degradomics (Strlič et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Volatile aldehydes in libraries and archives

Fenech

Strlič

Cigić

et al. 2010

Atmospheric Environment

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Volatile aldehydes are produced during degradation of paper-based materials. This may result in their accumulation in archival and library repositories. However, no systematic study has been performed so far. In the frame of this study, passive sampling was carried out at ten locations in four libraries and archives. Despite the very variable sampling locations, no major differences were found, although air-filtered repositories were found to have lower concentrations while a non-ventilated newspaper repository exhibited the highest concentrations of volatile aldehydes (formaldehyde, acetaldehyde, furfural and hexanal). Five employees in one institution were also provided with personal passive samplers to investigate employees' exposure to volatile aldehydes. All values were lower than the presently valid exposure limits.The concentration of volatile aldehydes, acetic acid, and volatile organic compounds (VOCs) in general was also compared with that of outdoor-generated pollutants. It was evident that inside the repository and particularly inside archival boxes, the concentration of VOCs and acetic acid was much higher than the concentration of outdoor-generated pollutants, which are otherwise more routinely studied in connection with heritage materials. This indicates that further work on the pro-degradative effect of VOCs on heritage materials is necessary and that monitoring of VOCs in heritage institutions should become more widespread.

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“…Transformer paper ages under the influence of heat, air and moisture and eventually loses all mechanical integrity, with risk increasing dramatically due to insulation damage [24].…”

Section: Cellulose Influencementioning

confidence: 99%

Determination of transformer oil quality by the acoustic method

2017

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Abstract. Large power transformers are the most expensive and strategically important components of any power generation and transmission system. Their reliability has crucial importance for the energy system operation. Insulation breakdown can generate a serious failure of a large power transformer, which causes substantial costs to repair and financial loss due to power outage. Most power utilities are, therefore, highly motivated to assess the actual condition of the transformer insulation system. The majority of transformer condition check methods are only available for off-line periodic diagnostics. The acoustic emission (AE) method as a complex online diagnostics technique to identify evolving failures is proposed. Results of measuring the acoustic signals generated by the presence of impurities in transformer oil and determining the impurities influence on its condition as an indicator of the transformer condition is presented.

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Kinetics and mechanisms of the low-temperature degradation of cellulose

Cited by 297 publications

References 44 publications

Study on the Effects of Thermal Aging on Insulating Paper for High Voltage Transformer Composite with Natural Ester from Palm Oil Using Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-ray Spectroscopy (EDS)

Study on the Effects of Thermal Aging on Insulating Paper for High Voltage Transformer Composite with Natural Ester from Palm Oil Using Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-ray Spectroscopy (EDS)

Volatile aldehydes in libraries and archives

Determination of transformer oil quality by the acoustic method

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