Hardening lead oxide

Although the element is a metalloid, the long, brittle, crystals have a metallic shine. The white, tasteless oxide (arsenic trioxide As203) has been famous and notorious ("inheritance powder") even after centuries traces can be found in bodies. The arsenic compound "Salvarsan" was first used by Paul Ehrlich for the treatment of syphilis — the start of chemotherapy. Popular today as a semiconducting material. Component of LEDs (light-emitting diodes) and lasers. Arsenic hardens lead, used earlier in letter-press printing, today only for lead shot. 

Styrene-butadiene rubber loaded with lead oxide was studied to determine its effectiveness as shield for y-radiation. The material did have the required performance but it gradually hardened on exposure to radiation ... 

The element antimony is used to harden lead for use in lead-acid storage batteries. One of the principal antimony ores is stibnite, which contains antimony in the form of Sb2S3. Antimony is obtained through the reduction that occurs (from the +3 oxidation state to the zero oxidation state of pure antimony) when Sb2S3 reacts with the iron in iron scrap. Wliat is the mass of antimony in 14.78 lb of Sb2S3 ... 

VSE In metallurgy as deoxidizer for copper, beryllium, steel (together with silicon). To harden lead for bearings. Alloyed with cerium to make flints for cigarette and gas lighters. In manuf of electronic vacuum tubes as getter to fix residual gases as oxides, nitrides, hydrides of calcium. 

Lead—tin (1.8—2.5 wt %) is used both as a cable sheathing ahoy (BS 801 ahoy A and DIN 17640) and as a battery connector ahoy ia sealed lead—calcium—tin batteries (15). Tia is generahy added to lead—arsenic cable ahoys ia smah amounts. The arsenic ahoys have excehent creep resistance and mechanical properties, but are unstable and lose arsenic readily by oxidation. The addition of smah amounts of tin (0.10—0.20 wt %) eliminates arsenic loss. Lead ahoys having 0.4 wt % tin and 0.15 % cadmium, which are used for cable sheathing, do not age harden, show excehent corrosion and creep resistance, and are very ductile. 

SBR also differs from NR in its aging behaviour. Whereas oxidation causes chain scission of the NR molecule and a softening of the rubber in bulk, SBR molecules tend to cross-link, this leading eventually to hardening and embrittlement. 

In modem manufacturing methods the oil is sometimes reacted directly with the glycerol to form a monoglyceride and this is then reacted with the acid to form the alkyd resin. When the resulting surface coating is applied to the substrate the molecules are substantially linear. However, in the presence of certain driers such as lead soaps there is oxidative cross-linking via the unsaturated group in the side chain and the resin hardens. 

Semimetal that occurs as a tin-type, brittle form and as a yellow, unstable, nonmetallic form. Its main use is in alloys to harden other metals. Without the addition of antimony, lead would have remained the "softy" of the Periodic Table. But with antimony, lead ruled the print world and later found use in the production of rechargeable batteries. It can be found in older ceramic glazing (yellow orange). Everyday encounters antimony sulfide in match heads and red rubber, antimony oxide is used as a flame retardant. Pure antimony is starting to become of interest in the electronics sector. 

Zinc-white Paint.—Like white lead, tho oxide of zinc requires to be mixed with an oily vehicle, to be applied in painting. As oxide of zinc does not readily form a saponaceous compound with fate or oils like oxide of lead the paint which is prepared with it and ordinary linseed ofl, does not dry or harden for a long time. This peculiarity was at first one of the principal... 

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