| 摘要 |
<p>Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of a mixture comprising: A) at least one stable hindered nitroxyl compound having structural formula (I) wherein R1 and R4 are independently selected from the group consisting of hydrogen, alkyl, and heteroatom-substituted alkyl and R2 and R3 are independently selected from the group consisting of alkyl and heteroatom-substituted alkyl; and X1 and X2 (1) are independently selected from the group consisting of halogen, cyano, COOR7, -S-COR7, -OCOR7, (wherein R7 is alkyl or aryl), amido, -S-C6H5, carbonyl, alkenyl, or alkyl of 1 to 15 carbon atoms, or (2) taken together, form a ring structure with the nitrogen; and B) at least one inhibitor selected from the group consisting of ortho-quinone, ortho-hydroquinone, para-quinone, para-hydroquinone, and derivatives of the foregoing.</p> |
