Appearance: light yellow or colorless transparent sticky liquid
Total formaldehyde (BASF method): 30.5-32.1%
Total ethanolamine (BASF method): 64.0-68.0%
PH (ISO 1148, 0.2% in distilled water): 9.0-10.0
Density: 20°C (DIN 53217/5): 1.15-1.16g/cm3
Inhibitors for certain element compounds
Elemental sulfur is not only a vulcanizing agent for rubber, but also a good polymerization inhibitor. Table 4-16 lists the reaction rate constants of polystyrene free radicals and poly(methyl meth)acrylate free radicals with sulfur.
Sulfur is a high-efficiency polymerization inhibitor for styrene, and has a very good inhibitory effect on vinyl acetate. The polymerization inhibitory constant is C2=470 (45°C).
The inhibitory effect of sulfur may be the addition reaction of free radicals and S: ring.
R·+S.RS, S·(4-54) It can be seen that elemental sulfur has a weak inhibitory effect on acrylic monomers. This is due to the fact that the S-S bond is easily broken by the attack of nucleophilic groups, but it is not susceptible to Attack of the electrophilic group. Therefore, sulfur cannot be used as a polymerization inhibitor for acrylate monomers having electron withdrawing groups.
The reaction of sulfur and olefins generally proceeds above 140°C, with hydrogen abstraction cationic paraffin wax emulsion of sulfur radicals, combination of sulfur radicals and olefin radicals, and addition of sulfur radicals. The inhibitory effect of sulfur may also cause chain radical termination through these reactions.
Nitrogen and sulfur compounds such as sodium sulfide, sodium dithiocarbamate and methine blue also have effective polymerization inhibition effects in some monomers.
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