| 摘要 |
It has been discovered that the polymerization of vinyl aromatic compounds, such as styrene, may be inhibited by the addition of a composition that contains a hindered hydroxylamine, and, optionally, a synergist together with the hindered hydroxylamine. In one embodiment of the invention, the hindered N,N-disubstituted hydroxylamine has the formula:where R1, R2, and R3 are independently selected from the group consisting of hydrogen, straight, branched or cyclic alkyl, aryl, aralkyl, and alkaryl moieties; where no more than two of R1, R2, and R3 on each C can be hydrogen at a time; where one or more of R1, R2, and R3 on one C may be joined to a R1, R2, and R3 on the other C to form a cyclic moiety selected from the group consisting of alkylene, and aralkylene moieties; where any two of the R1, R2, and R3 on any one C may be joined together to form a cycloalkyl; where any of the above definitions of R1, R2, and R3 may contain one or more heteroatoms selected from the group consisting of N, O and S; and where the total number of carbon atoms in the hindered N,N-disubstituted hydroxylamine ranges from 6 to 70. Optional synergists may include alkyl-substituted hydroxyarenes such as 2,5-di-tert-butylhydroquinone, and hydrogen transfer agents such as 1,2,3,4-tetrahydronaphthalene; and the like, and mixtures thereof. |
