Rapid measurement of the deterioration of oil immersed paper

The thermal deterioration of oil immersed paper was investigated by mass spectrometer and gas chromatograph. The results obtained are as follows: 1. It was shown that a new assembly using a mercury diffusion pump and Topler pump is very effective for extracting small amounts of gas from oil. 2. The thermal deterioration of kraft paper in oil can be studied over a wide temperature range from high temperatures to normal working temperatures. The thermal deterioration characteristic of kraft paper shown by the logarithm of the generation rate of (CO + CO₂) = (Δq) vs 1/T is generally made of two offset line segments of differing slopes. This result differs from those for other materials.3, 4 3. The slope of log (1/Δq) vs 1/T curve above described co-incides with the slope of log (life) vs 1/T plot obtained in measurements of the mean degree of polymerization. 4. According to the above results, the thermal life of kraft paper in oil at normal working temperatures can be estimated using together two types of information: (a) the slope of log (1/ Δq) vs 1/T and (b) the results of actual life tests made at much higher than normal temperatures.