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Low temperature thermal degradation of cellulosic insulating paper in air and transformer oil
Author(s) -
Soares Sandra,
Ricardo Nágila M P S,
Heatley Frank,
Rodrigues Edison
Publication year - 2001
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.625
Subject(s) - degradation (telecommunications) , kraft paper , furfuryl alcohol , materials science , degree of polymerization , cellulose , atmospheric temperature range , transformer oil , chemical engineering , polymerization , thermal , composite material , organic chemistry , polymer chemistry , pulp and paper industry , transformer , chemistry , polymer , thermodynamics , electrical engineering , physics , voltage , engineering , catalysis
Abstract The thermal degradation of cellulose in the form of Kraft insulating paper has been studied in air for up to 140 h and in transformer oil for up to 3500 h in the temperature range 60–120 °C using measurements of the degree of polymerization ( DP ) and (in oil) analysis of furanic degradation products. Degradation was faster in air than in oil. The DP decreased from the original value of 1.2 × 10 3 to a limiting value in the range of 300–900 depending on temperature and degradation conditions. The variation of the DP with degradation time was consistent with two mechanisms, one in which the first‐order rate constant decreased exponentially with time, and another in which only a limited number of chain bonds were scissionable. The degradation rate was first order in scissionable bonds. The major furanic degradation products were 2‐furaldehyde, 5‐hydroxymethyl‐2‐furaldehyde and furfuryl alcohol. Their concentrations continually increased over the timescale of the experiments. © 2001 Society of Chemical Industry