Collodion cotton contaminated

Even when confined in the closed cell and subjected to the isothermal storage test performed at a T, of 65 °C, 0.4 g of collodion cotton contaminated by metals, above referred to, started the autocatalytic reaction, though faintly, about 12.8 d after the start of the isothermal storage test. The sample was found to be yellow and gave off the odor of nitrogen dioxide after the test the inside of the cell was found to be pressurized besides. 

Figure 127. Comparison of the plot of In versus l/Ti made with seven combinations of the value of InZl/ with that of // which are each determined for seven induction periods, of the autocatalytic reaction, of 0.4 g each of seven samples of collodion cotton (11.75 % N), contaminated by metals, confined each in the closed cell and subjected each to the isothermal storage test pcrfomied at each 7", in the range of 66.95 to 90.08 C with mutual intervals of 1 5 K, recorded each for the time, At, from the insertion of each cell into the isothermal storage testing device till the start of the autocatalytic reaction of collodion cotton contaminated by metals at the corresponding T with, the plot made for 0.4 g each of nine samples of normal collodion cotton 12.19 % N) placed each under the same conditions as the former, fhe latter plot is quoted from Fig. 126, for comparison.

In this connection, a case should also be mentioned here that an SADT of 69.1 °C was calculated for a certain lot of collodion cotton (11.75 % N), which was thought to be contaminated by trace amounts of metals which might have been derived from the nitration process (Fig. 127). 

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