Detection And Release Rule Of Gases Emitted From Ship-used Coatings

The sealed cabin of ship is a limited space, and a large number of nonmetallic materials are used in the cabins. Some nonmetallic materials may continuously emit toxic gas and atmosphere in the cabins may be polluted.In this paper, the coatings used in the sealed cabins of ship were brushed on aluminum board and the aluminum boards were exposured to air for drying for a month. Then the Aluminum boards were taken into the stainless steel cabin which volume is 100L and sealed. The sealed cabin was kept at 50℃for 72 hours. A method for the determination of toxic gases such as volatile organic compounds ( VOCs ), carbon monoxide ( CO ) and total volatile organic compounds ( TVOCs ) released from the paints was established. CO was analyzed by gas chromatography with the flame ionization detector. TVOCs was analyzed by gas chromatography with the photo ionization detector. And VOCs were concentrated by sample tube filled with tenax TA sorbent and the analysis was carried out by thermal desorption-gas chromatography-mass spectrometry with capillary columns. The correlation coefficients of the calibration curves were more than 0.994. The recoverys were more than 85%. The relative standard deviations (RSD) were less than 10% respectively. Applying the methods established, the toxic gases released from paints by heating, were observed. More than 50 toxic gases released from 4 paints, such as aldehyde, ketone etc. were tested.In the sealed cabin,the concentration and the kinds of toxic gases released from paints at different equation time were determined. The experiments were done at the temperature of 25℃, 50℃, 65℃respectively. When at 25℃, the concentration of gases released from paints increased with the sealed time. After balancing 60 days, the concentrations of different contaminations did not come to balance. When at 50℃, the balances of gases released from paints just need 3 days. When at 65℃, the balances just need 2 days. The rule of the concentration about the toxic gases released from the paints in the sealed cabin was obtained. According to the result, two mathematical model of about volatile organic compounds in the test processes were deduced, fitted and built. Use the models to fit data and check up the correlations. According to fitting result to the experiment data, the corelation result of the second model, which is C(t) =k₁A(e^-k₂t-e^-k₁t) /[(k₁-k₂)V], is very good.