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Tribasic lead sulfate

By far the most common lead salt used for PVC stabilization is tribasic lead sulfate. It can be found either alone or combined with another lead salt in almost every lead-stabilized PVC formulation. Many of the combinations are actually coprecipitated hybrid products, ie, basic lead sulfophthalates. Dibasic lead stearate and lead stearate are generally used as costabilizers combined with other primary lead salts, particularly in rigid PVC formulations where they contribute lubrication properties dibasic lead stearate provides internal lubrication and lead stearate is a good external lubricant. Basic lead carbonate is slowly being replaced by tribasic lead sulfate in most appHcations due the relatively low heat stabiHty of the carbonate salt which releases CO2 at about 180°C during PVC processing. [Pg.551]

Rigid Applications. The use of the lead stabilizers is very limited in the United States but, they are stiU used in several rigid PVC appHcations in Europe and Asia. The highest use of lead stabilizers in rigid PVC is for pipe and conduit appHcations. Tribasic lead sulfate is the primary heat stabilizer with lead stearates included to provide lubrication. The lead products are typically fully formulated, usually including lubricants and pigments for pipe extmsion appHcations. These lead one-packs, when used at about 1.8—2.5 phr, provide all of the stabilizer and lubrication needed to process the polymer. A lead one-pack contains tribasic lead sulfate, dibasic lead stearate calcium stearate, polyethylene wax, paraffin wax, ester wax, and pigments. [Pg.552]

Tribasic Lead Sulfate. Tribasic lead sulfate [12202-17 ] 3PbO PbSO 2 hue white powder, mol wt 890.93, sp gr 6.9, refractive... [Pg.70]

Stabilizers. Lead stabilizers, particularly tribasic lead sulfate, is commonly used in plasticized wire and cable compounds because of its good nonconducting electrical properties (122). [Pg.503]

Paste mixing means the addition of sulfuric acid and water. The result is a fairly stiff paste with a density between 1.1 and 1.4gcm 3 containing 8-12wt% of lead sulfate. The water content of thus mix determines the porosity of the active material achievable later (cf. "curing" below). In the paste, a mixture of lead sulfate and basic lead sulfate is formed (cf. Table 1). In the usual mixing process between room temperature and 50 °C, tribasic lead sulfate is formed. The generation of the tetrabasic... [Pg.166]

Tribasic acid, 18 817 Tribasic lead silicate, 14 796 Tribasic lead sulfate, 14 790 for PVC polymers, 25 671 Tribenzoate chiral stationary phase, 6 88t Tribenzylbismuthine, 4 27 Tribenzylether chiral stationary phase, 6 88t... [Pg.967]

Lead compounds are generally added to polyvinyl chloride in electrical formulations in order to stabilize them against thermal decomposition 7 p.h.r. of National Lead Tribase XL modified tribasic lead sulfate was used throughout the present study. Since the stabilizer itself is an ionic impurity, it is remarkable to note that it actually increases volume resistivity (Table IV). [Pg.150]

Figure 5.11 Infrared spectra of 50/50 PVC/NBR blends after mixing (a) for 5 minutes, (b) for 60 minutes (stabilised with tribasic lead sulfate) at 180 °C, (c) at 160 °C, (d) at... Figure 5.11 Infrared spectra of 50/50 PVC/NBR blends after mixing (a) for 5 minutes, (b) for 60 minutes (stabilised with tribasic lead sulfate) at 180 °C, (c) at 160 °C, (d) at...
Lead compounds, usually based on a mixture of lead salts, e.g., tribasic lead sulfate or dibasic lead phosphite, and lead soaps, e.g., dibasic or normal lead stearates, have been very cost effective heat stabilisers for many years, and function as HC1 absorbers (236, 365,438). [Pg.14]

Dried chlorella powder and PVC (n llOO) were used. As the stabilizer some chemical additives were used. These chemicals were dibasic lead stearate (DEL), tribasic lead sulfate (TC),cadmium/barium/lead fatty acids complex (U500), barium/zinc fatty acids complex (PSE) and paraffin. Usually we used the mixture of 20% chlorella and PVC with TC 1.5%, DEL 0.5%, 1 500 0.5% of PVC respectively. [Pg.479]

Lead Compounds—These were among the earliest stabilizers. Although quite effective as heat stabilizers, they are toxic, impart opacity to PVC compounds, and cause black coloration with time because of poor sulfide stain resistance. The primary use for lead compounds is in electric applications such as wire coatings. The principal lead compounds for this use are tribasic lead sulfate, basic lead sulfate silicate, basic lead carbonate, and basic lead phthalate. Use levels usually range from 3 to 8 parts-per-hundred parts of PVC (phr). [Pg.427]

Enviro-Stab 1092. [Monson Chem.] Tribasic lead sulfate, enci ulated. [Pg.132]

Stabilizers are almost invariably added to PVC to improve its heat and light stability. The species found effective in stabilizing PVC are those that are able to absorb or neutralize HCl, react with free radicals, react with double bonds, or neutralize other species that might accelerate degradation. Lead compounds, such as basic lead carbonate and tribasic lead sulfate, and metal soaps of barium, cadmium, lead, zinc, and calcium are used as stabilizers. Obviously, they can react with HCl. Epoxy plasticizers aid in stabilizing the resin. Another group of stabilizers are the organotin compounds, which find application because of their resistance to sulfur and because they can yield crystal-clear compounds. [Pg.111]

This lead compound forms prismatic crystals with a length of 1—4 pm and 0.2—08 pm in cross section. Its density is 6.5 g cm. It is poorly soluble in water, 0.0262 g L. 3BS is obtained when leady oxide is mixed with sulfuric acid solution (up to 8 wt % H2S04/Pb0) and constitutes the basic component of the battery paste when the latter is prepared at temperatures below 70 °C. Tribasic lead sulfate exerts an influence on the structure of the lead dioxide active mass and thus on some of the performance characteristics of the battery. [Pg.37]

Tribasic Lead Sulfate Pastes, 3PbO PbS04- H2O (3BS)... [Pg.258]

Tribasic lead sulfate pastes are most widely used in the battery industry for the production of both positive and negative plates. The reason for this preferential application of these pastes is the quick and easy formation (nucleation and growth) of 3BS, and the appropriate size and structure of the obtained 3BS particles and agglomerates. [Pg.258]

Preparation of tribasic lead sulfate (3BS) pastes for positive plates. [Pg.298]

Tribasic lead sulfate (3Pb0-PbS04 -H20) eontains water in its molecule. On heating the paste samples during the differential thermal gravimetrie (DTG) measurements, this water evaporates and the samples lose weight. [Pg.422]


See other pages where Tribasic lead sulfate is mentioned: [Pg.1009]    [Pg.546]    [Pg.551]    [Pg.552]    [Pg.552]    [Pg.70]    [Pg.576]    [Pg.578]    [Pg.579]    [Pg.146]    [Pg.546]    [Pg.551]    [Pg.552]    [Pg.552]    [Pg.1687]    [Pg.371]    [Pg.576]    [Pg.578]    [Pg.579]    [Pg.124]    [Pg.599]    [Pg.398]    [Pg.840]    [Pg.841]    [Pg.37]    [Pg.253]   
See also in sourсe #XX -- [ Pg.138 , Pg.145 , Pg.150 , Pg.201 , Pg.204 , Pg.211 , Pg.212 , Pg.279 , Pg.327 , Pg.328 , Pg.329 , Pg.332 ]

See also in sourсe #XX -- [ Pg.364 ]

See also in sourсe #XX -- [ Pg.73 , Pg.74 , Pg.75 , Pg.94 , Pg.96 , Pg.97 , Pg.98 , Pg.99 , Pg.196 ]




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