Copper stearate concentration, effect

Effect of Copper Stearate Concentration. As mentioned above, the thermal oxidation of the polymer catalyzed by copper compound (7.9 X 10 4M) proceeds very rapidly at the early stage and shows the leveling off of the oxygen uptake. Thus, the effect of the concentration of the copper stearate on the oxidation of the polymer was examined. The oxygen uptake curves of the thermal oxidation of the polymer in the presence of 3.2 X 10 5Af-7.9 X 10 3M copper stearate are shown in Figure 5. In this figure, the thermal oxidation of the neat polypropylene proceeds almost linearly. However, the copper stearate-catalyzed thermal oxidation of the polymer is affected remarkably by the copper concentration. In the presence of less than 3.2 X 10 3M copper stearate, the... 

Effects of a series of transition metal stearates, the concentration of the copper stearate, the solvent, various additives, and other factors on the thermal oxidation of polypropylene were studied in trichlorobenzene solution. The mechanism of copper catalysis is discussed. The order of decreasing catalytic activity of the metal stearates was Cu > Mn > Fe > Cr > Al Ni Co control Ti >> Zn >> V. The addition of propionic acid to the solvent accelerated the oxidation of the polymer. The presence of the copper leveled off oxygen uptake of the polymer after a certain time. The amount of oxygen absorbed decreased with increasing concentration of the copper, and at higher concentration (7.9 X 10 3M) the polymer oxidation was inhibited. 

In this chapter, the effect of a series of transition metal stearates on the thermal oxidation of polypropylene in homogeneous solution is examined, and the results obtained are compared with that in bulk reported previously (16). In addition, the effects of the anion of copper compounds, the concentration of copper, the solvent, and the additives on the copper compound-catalyzed thermal oxidation of polypropylene are studied, and the mechanism of the copper catalysis in solution is discussed. 

Effect of salts of varivalent metals [2, 3] Additives of the stearates of iron (IS), copper (CpS), cobalt (CbS), zinc (ZS), and lead (LS) within a certain concentration range were found to increase the polymerization rate of styrene and methylmethaciy-late (MMA) in comparison with thermal polymerization. By initiating activity, they can be arranged as LS < CbS < ZS < IS < CpS. 

Metals (copper and copper alloys, nickel, iron) have a strong adverse effect on PE because they accelerate degradation. Metal deactivators (organic molecnles containing heteroatoms or functional groups such as hydroxyl or carboxyl) act by chelation of the metal to form inactive or stable complexes. The concentration used is about 1 %. Acid scavengers (or antiacids) are used to neutralise acidic catalyst residues. Calcium or zinc stearate are commonly used, and also function as internal lubricants. Inserts should be made of light metal or he nickel or chromium plated. 

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