Cd-stearate

Thermal behavior of Cd stearate, Cd arachidate and Cd behenate mono-layers was studied by Riegler [53] using electron diffraction. This study confirmed the previous observations on the disordering of the monolayers starting well before the melting temperature. The relationship between the length of the alkyl chain and the temperature at which the alkyl... 

This is illustrated in Fig. 9.4. The synergetic effect of Ba and Cd stearate mixtures has been previously explained by their different capacity to stabilize coloration as well as to react with HCl. In the first place, HCl reacts with barium stearate, and BaCl2 thus formed does not affect dehydrochlorination or coloration. On the other hand, cadmium stearate is a better coloration stabilizer and it will not be affected by HCl as long as barium stearate is not completely reacted with HCl. When this is done, cadmium stearate begins to react with HCl, and the CdCl2 formed accelerates the coloration process after a while [51]. 

Whereas other metal salts, especially lead stearates and srdfates, or mixtures of Groups 2 and 12 carboxylates (Ba—Cd, Ba—Zn, Ca—Zn) ate also used to stabilize PVC, the tin mercaptides are some of the most efficient materials. This increased efficiency is largely owing to the mercaptans. The principal mechanism of stabilization of PVC, in which all types of stabilizers participate, is the adsorption of HCl, which is released by the PVC during degradation. This is important because the acid is a catalyst for the degradation, thus, without neutralization the process is autocatalytic. 

The sohd soaps are prepared from cadmium chloride solution by precipitation with sodium salts of the fatty acids. Cadmium laurate [2605-44-9] Cd(C22H2402)2, cadmium stearate [2223-93-0] cadmium palmitate [6427-86-7] and cadmium myristate [10196-67-5] ... 

Heat stabiliser Organotin mercaptides/sulfides/carboxylates antimony mercaptides metal carboxylates lead stearate/phosphite/phthalate/sulfate S, Sb, Sn, Ba, Ca, Cd, Mg, Sr, Zn P, Pb, S... 

Metallic (Cd, Zn, Ba) stearates Polymers Alternating current polarography... 

Zinc, nickel, lead, and cadmium salts Ba-Cd-Zn stabilizers Organo-nickel complexes CdS, CdSe, lead stearate Cadmium laurate Stabilizers Pigments Lubricants... 

Materials. The polymer samples were prepared either by physical blending of PVC with an EVA copolymer or by suspension polymerization of vinyl chloride with the EVA copolymer dissolved in the monomer. The resulting dried polymer samples were blended with additives (organic Ba-Cd stabilizer and Pb-stearate) to the following general composition ... 

Four main types of antioxidants are commonly used in polypropylene stabilizer systems although many other types of chemical compounds have been suggested. These types include hindered phenolics, thiodi-propionate esters, aryl phosphites, and ultraviolet absorbers such as the hydroxybenzophenones and benzotriazoles. Other chemicals which have been reported include aromatic amines such as p-phenylenediamine, hydrocarbon borates, aminophenols, Zn and other metal dithiocarbamates, thiophosphates, and thiophosphites, mercaptals, chromium salt complexes, tin-sulfur compounds, triazoles, silicone polymers, carbon black, nickel phenolates, thiurams, oxamides, metal stearates, Cu, Zn, Cd, and Pb salts of benzimidazoles, succinic acid anhydride, and others. The polymeric phenolic phosphites described here are another type. 

When used in PVC organophosphites act as secondary heat stabilizers. In other resins such as PP, PS, HOPE and ABS plastics they function as antioxidants. p-Diketones are well-known co-stabilizers more particularly for zinc carboxylates. The synergistic action of epoxidized fatty acid esters like ESO or butylepoxy stearate as plasticizer, HCl scavenger and stabilizer for labile chlorine atoms in the catalytic presence of Zn and Cd salts is shown in Fig. 7 (see also 5.2.3)... 

Figure 3.2. Induced CD (curves 1-3) and UV (curve 4) spectra of Wilkinson catalyst, RhCl(PPli3)3, included into the chiral matrix of the liquid crystal cholesteryl stearate at 67"C in 1-butanol (adapted from Pavlov etal.

Metallic soaps, i.e. salts of fatty acids such as myris-tates, palmitates, stearates (Me Ca, Cd, Ba, Mg, Zn, Al) and especially the partially saponified montan waxes may he regarded as model compounds for the metal-containing PE waxes. 

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