acrolein and acrylic acid
Acrolein and acrylic acid (AAc) are valuable industrial chemicals. Acrolein is used in the manufacture of polyester resins, polyurethanes, PG, AAc and acrylonitrile. AAc is produced industrially by the oxidation of propylene, whereas the hydrocarboxylation of acetylene (Reppe process) is only of historical interest. AAc and its esters are used in the synthesis of various homopolymers or copolymers for plastics, coatings, adhesives, elastomers, and polymers for paints and coatings, superabsorbents, water treatment, paper, and textiles Dispersions. Glycerol dehydration can be considered as a green route to produce acrolein and AAc. 373 This reaction is usually carried out over immobilized acidic catalysts. Gas phase dehydration is preferred to reduce the formation of by-products from the degradation of acrolein and polymerization which lead to catalyst deactivation. For the synthesis of AAc, the dehydration of glycerol is carried out under an oxygen atmosphere that promotes the immediate oxidation of acrolein to AAc, or the dehydrated product is sent through a separate oxidation reactor. 374
Acrolein is a highly volatile yellow liquid mainly used in the production of acrylic acid and acrylates. Non-occupational exposure occurs through smoking, house fires, vehicle exhaust, heating animal or vegetable oils, and treatment with cyclophosphamide. Acrolein is more corrosive to the skin, eyes and respiratory tract than formaldehyde. 1% solution can cause chemical burns. Eye irritation starts at 0.15–0.25 ppm, 1 ppm cannot be tolerated [29]. Aspiration causes ARDS with massive shedding of cells from the bronchial lining and possibly death [30]. In 1993, Mahut et al. [31] reported a case of severe poisoning in a 27-month-old child who inhaled fumes from burning vegetable oil for 1 hour in his parents' kitchen. Eighteen months later, the boy developed persistent expectoration, and a CT scan revealed emphysema, localized atelectasis, and diffuse bronchiectasis.
There are no data on the long-term effects of acrolein in humans.
