Lead tricinate

Lead tricinate, -> tetracene, -> Barium Nitrate, lead dioxide, antimony trisulfide and calcium silicide. These components meet all requirements currently applied in ammunition technology. SINOXID compositions feature very good chemical stability and storage life, they are abrasion-, erosion- and corrosion-free and ignite propellants with precision. 

To keep the reaction centers open i.e. in a photoactive condition the chromatophore solutions were purged with nitrogen for an hour, after which a 10 - 50 mM sodium-dithionite solution (in 250 mM Tricine) was added to ensure that the first quinone acceptor af the RC, is maintained in the reduced state (2a)- Under these conditions illtimination of the sample leads to a primary charge separation, but this state will recombine on a nano-second time-scale. At 77 K none of the recombination will occur via the excited singlet state, but at higher temperatures slow emission decay components can be observed due to this recombination (4). However this will not interfere with the measurements of the trapping time reported here, inview of the large difference in time-scales. ( <100 ps vs. 10 -20 ns). 

The replacement of mercury was a significant improvement with respect to the toxicity of the combustion products. It led, however, to the introduction of tricinate which also presents health problems due to its lead content. Concerns over environmental hazards resulted in the search for lead-free or, more generally, heavy metal-free compositions which would eliminate the health threat while maintaining performance and other important properties at least to the level of lead-containing predecessors [5]. 

Various new energetic materials have been designed and tested as potential candidates for replacement of the lead substances. The green priming mixtures for percussion caps of small arms ammunition for indoor shooting usually use DDNP or tetrazene (or both) as a replacement for tricinate. DDNP, although better than lead salts, is reported to cause some allergic reactions [10]. Example compositions without heavy metals are summarized in Table 1.4. 

Lead styphnate (lead salt of 2,4,6-trinitrobenzene-1,3-diol, LS, LTNR, tricinate) was, according to the well-established reference [8], first prepared by Edmund von Herz in 1914 by reaction of magnesium styphnate with lead acetate in presence of nitric acid. However, in reality, preparation of LS was published more than 40 years earlier by Stenhouse [28]. This discrepancy in historical data is probably caused by the fact that Herz patented the substance as a component of a detonator primary charge and was therefore the first one who found some real application [29,30]. The preparation route used by Stenhouse is based on the reaction of lead acetate with an aqueous solution of styphnic acid [28]. 

On the other hand, Tris buffer and Tricine buffer were rather inhibitory to photocurrent output. Addition of lOmM CaCl2 to the borate buffer leads to an increased output, but it is not true for MgCl2 and BaCl2. 

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