METHODS AND COMPOSITIONS FOR INHIBITING POLYSTYRENE FORMATION DURING STYRENE PRODUCTION

摘要

Methods and compositions are provided for inhibiting the polymerization of a vinyl aromatic monomer, such as styrene monomer, during elevated temperature processing or distillation thereof. The compositions comprise an inhibitor combination of (A) a hydroxylamine and (B) a stable free radical plus a retarder that is either; (C) dinitrobutylphenol or (D) quinone methide. The ratio of (A) to (B) ranges from about 5% (A) to 95% (B) to about 95% (A) to about 5% (B). The compositions are added to the vinyl aromatic monomer in amounts sufficient to prevent polymerization during the distillation process. Typically the inhibitor combination is added to the vinyl aromatic monomer in an amount ranging from about 10 to 150 ppm of the monomer. Retarders are typically added in an amount ranging from 50 to 1500 ppm of the vinyl aromatic monomer.

主权项

1. A method for inhibiting the polymerization of a vinyl aromatic monomer comprising:
adding to the monomer an effective polymerization inhibitor combination comprising (A) a hydroxylamine; and (B) stable free radical.