| 摘要 |
1342208 Inhibiting diene polymerization SNAM PROGETTI SpA 25 Feb 1972 [3 March 1971] 8921/72 Heading C5E Solutions of conjugated dienes in a solvent at elevated temperature are stabilized against polymerization by the addition of a halogencontaining benzoquinone derivative, e.g. in amount 50-200 p.p.m. Suitable inhibitors are are 2,5- and 2,6-dichloro-p-benzoquinone, 2,3- dichloro - 5,6 - dicyano - p - benzoquinone, chloranil, bromanil, iodanil or a mixture of two or more thereof, optionally mixed with a known inhibitor such as an aro matic nitro compound, mercaptobenzothiazole, p - benzoquinone - dioxime, p - t - butyl catechol furfurol and benzaldehyde. Suitable solvents for conjugated dienes are sulpholane, furfural, acetone, acetonitrile, DMF, dimethylacetamide, NMP, #-methoxypropionitrile, aniline, morpholine, formylmorpholine, 4-methylmorpholine acetone-morpholine or a mixture thereof optionally containing water. Stabilization is useful during recovery of butadiene or isoprene by extractive distillation. |
