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Various testing methods |
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1. Tests on sensitivity to decomposition and firing |
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Flash point test
(Tag type, Setaflash type, and Cleveland type)
The flash point is defined as the temperature at which ignition of the test material is observed by an open flame over the test material heated to a certain temperature. |
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Rapid heat test
The test material (1g) is put in a test tube, and heated using an electric heating plate at an increasing rate of 4°C/min. to observe the temperature at which the test material starts decomposing and decomposition status. |
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SADT (BAM method)
[Self-Accelerating Decomposition Temperature]
The test material (400ml) is put in a dewar vessel, which is contained in a chamber in which air at a certain temperature is circulating. This process is carried out to investigate whether the test material decomposes, generates heat (to a temperature increase of over 6°C) under certain temperature conditions, and the rate of decomposition.
A United States SADT test is conducted for the same purpose. This test uses a packaged organic peroxide product available in the market instead of tests using a small amount of organic peroxide in the dewar vessel. However, this method has the disadvantage of difficulty in use from safety and environmental pollution respects. |
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Ignition temperature (ASTM E659 method)
A 500ml flask is placed in a electric furnace with the temperature controlled adequately, and the test material (0.15ml) is put in the flask. In this method, the lowest temperature that induces ignition is measured to decide the ignition temperature (auto-ignition temperature).
Organic peroxides undergo thermal decomposition, and almost all organic peroxides show rapid decomposition accompanied by white smoke before ignition. |
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Falling weight sensitivity
Testing is carried out using a falling weight sensitivity tester which is used for explosives. The test material (0.1g) is placed on an anvil, and a roller is placed on the test material. A 5kg iron hammer falls on the top of the steel rod, and ignition or explosion of the test material is tested to observe the highest position of the iron hammer not causing ignition or explosion in ten drop tests. This method shows the sensitivity of organic peroxide against impact by a weight as well as the sensitivity to friction. |
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Friction sensitivity (BAM type)
The tester is equipped with a friction rod and plate made of porcelain. A small amount of the test material is placed between the rod and plate.
Friction motion is caused under a load, and the sensitivity of the organic peroxide is studied from the relationship between load and explosion. |
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2. Decomposition power |
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Ballistic mortor test
Testing is carried out using a steel block and the No.6 blasting cap in a rigid enclosure. The blasting cap explodes (or decomposes) 10g of the sample. The deflection angle of the weight is compared with a reference of TNT as 100%. This indicates the explosive power of the sample. |
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Pressure vessel test
The pressure vessel made of stainless steel is equipped with a bursting aluminum disc with a pressure resistance of 10kg/cm2 and a port for installing a round plate with an orifice of the selected diameter at the side of the vessel. The vessel has an inner capacity of about 235cm3, in which 5g of the test material is placed for thermal decomposition under certain conditions. The violence of decomposition power is measured from the orifice with the minimum diameter required to maintain the inner pressure at 10kg/cm2 |
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DSC
A stainless steel, closed-type vessel is used for tests. About 1mg of the test material is put inside the testing vessel, and is heated up at 10°C/min. The temperature at which decomposition starts (Tb: Temperature at intersectional point) and the heat of decomposition are measured. |
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