Synthesis
First, stearic acid is dissolved in 20 times its weight of hot water, and a sodium hydroxide solution with a mass concentration of 1074 kg/m³ is added. A saponification reaction is carried out at approximately 75°C to produce a dilute sodium stearate solution. Metallic cadmium is dissolved in sulfuric acid and nitric acid to prepare a cadmium sulfate solution. This cadmium sulfate solution is then added to the sodium stearate solution, and a double decomposition reaction is carried out at approximately 55°C. The product, cadmium stearate, precipitates out. After filtration and washing with water, the product is dried at 70°C–75°C to obtain the final product.
Figure 1 shows the reaction formula for preparing cadmium stearate.
Uses
It is a heat stabilizer and lubricant for PVC, and an excellent variety of main metal soap heat stabilizers. It exhibits low initial colorfastness, excellent light stability and transparency, and imparts good thermal stability, weather resistance, lubricity, and transparency to products. It can be used alone, but the cadmium chloride formed after absorbing hydrogen chloride promotes the dehydrochlorination reaction. It is often used in combination with barium soaps, organotin compounds, epoxy compounds, or phosphites, showing a significant synergistic effect. It is often used in combination with barium soaps, barium-zinc soaps, or barium-lead soaps for soft products such as films, sheets, and artificial leather. Its processing operability is not very good; plasticization is incomplete at low processing temperatures, and it is prone to charring at excessively high temperatures. In rigid products, it can improve processability when combined with lead stabilizers. It has the disadvantage of being susceptible to sulfide contamination. Large doses can easily lead to segregation and scaling. It is toxic and not suitable for use in products that come into contact with food.
The overview, physicochemical properties, preparation methods, product standards, and uses of cadmium stearate are compiled and edited by Ding Hong of Chemicalbook. (2016-04-25)
Description
admium stearate is a crystalline solid.Molecular weight=698.5. Hazard Identification (based on512 Cadmium stearateNFPA-704 M Rating System): Health 3, Flammability 1,Reactivity 0.
Chemical Properties
Cadmium stearate is a crystalline solid.
General Description
Solid. Used as a lubricant and stabilizer for polyvinyl chloride.
Reactivity Profile
Cadmium stearate has weak oxidizing or reducing powers. Redox reactions can however still occur. The majority of compounds in this class are slightly soluble or insoluble in water. If soluble in water, then the solutions are usually neither strongly acidic nor strongly basic. These compounds are not water-reactive.
Health Hazard
Similar to cadmium; acute toxicity most notably occurs secondary to cadmium ingestion or inhalation of cadmium fumes. Poisoning from inhalation is relatively rare but dangerous, having a mortality rate of about 15 percent. Toxic inhaled concentrations in humans have been reported at 147 mg/m3/35 minutes and at 1800 mg/m3/2 years.
Fire Hazard
Cadmium stearate emits acrid smoke when heated to decomposition.
Safety Profile
Confirmed human
carcinogen. Poison by inhalation.
Moderately toxic by ingestion. Human
systemic effects by inhalation:
hallucinations or dstorted perceptions;
nausea or vomiting, other gastrointestinal
effects; weight loss or decreased weight gain;
cardiac effects. When heated to
decomposition it emits toxic fumes of Cd.
See also CADMIUM COMPOUNDS.
Potential Exposure
Used as a lubricant and stabilizer in
polyvinyl chloride plastics
First aid
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seekmedical attention immediately. If this chemical contactsthe skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove fromexposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing hasstopped and CPR if heart action has stopped. Transferpromptly to a medical facility. When this chemical hasbeen swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.Note to physician: For severe poisoning do not use BAL[British Anti-Lewisite, dimercaprol, dithiopropanol(C3H8OS2)] as it is contraindicated or ineffective inpoisoning from cadmium.
storage
Color Code—Blue: Health Hazard: Store in asecure poison location. Prior to working with Cadmiumstearate you should be trained on its proper handling andstorage. A regulated, marked area should be establishedwhere this chemical is handled, used, or stored. Store intightly closed containers in a cool, well-ventilated area,away from incompatible materials. Where this chemical isused, handled, manufactured, or stored, use explosion-proofelectrical equipment and fittings.
Shipping
UN2570 Cadmium compounds, Hazard Class:
6.1; Labels: 6.1-Poisonous materials, Technical Name
Required.
Incompatibilities
Cadmium stearate has weak oxidizing or
reducing powers. Redox reactions can however still occur
