Reference

Inhibiting polymerization of vinyl aromatic monomers

Inhibiting polymerization of vinyl aromatic monomers. Miller, Richard F.; Nicholson, Michael P. (Atlantic Richfield Co., USA). U.S. US 4465882 A 14 Aug 1984, 6 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C07C007-18. NCL: 585004000. APPLICATION: US 83-530295 8 Sep 1983. DOCUMENT TYPE: Patent CA Section: 35 (Chemistry of Synthetic High Polymers) A polymn. inhibitor compn. for vinyl arom. compds. comprises (A) 31 N,N'-dimer of phenothiazine, its alkyl, haloalkyl, or halo derivs. and (B) 31 hydroxylamine contg. 2 N-substituted, arom. radical-contg. hydrocarbyl groups. Thus, 500 ppm mixt. comprising 20% dibenzylhydroxylamine (I) [621-07-8] and 80% 10,10'-diphenothiazine (II) [79430-78-7] was added to 100 g styrene [100-42-5] contg. NaOH and Bz2O2, and the mixt. was heated at 90° for 2 h. The amt. of polymer formed was 0.036%, compared with 8.3% in the presence of I alone and 0.28% in the presence of II alone.

Inhibiting polymerization of vinyl aromatic monomers

Inhibiting polymerization of vinyl aromatic monomers. Miller, Richard F. (Atlantic Richfield Co., USA). U. 98-29-3 and 88-58-4 are also occured in this study.S. US 4434307 A 28 Feb 1984, 6 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C07C007-18. NCL: 585004000. APPLICATION: US 82-453070 27 Dec 1982. DOCUMENT TYPE: Patent CA Section: 35 (Chemistry of Synthetic High Polymers) Vinyl arom. compds. are stabilized against undesired polymn. by addn. of small amts. of >1 N,N-diarylhydroxylamine and >1 mono- or ditertiary alkylcatechol and (or) >1 mono- or ditertiary alkylhydroquinone. Thus, 100 g styrene [100-42-5] contg. Na+ 10, Bz2O2 200, and N,N-dibenzylhydroxylamine (I) [621-07-8]-2,5-di-tert-butylhydroquinone (II) [88-58-4] mixt. 500 ppm had 0.01% polymer content after 120 min at 90 ± 2°, whereas a similar mixt. contg. 500 ppm I instead of I-II mixt. had 8.03% polymer content, and in the absence of inhibitor the polymer was too viscose to remove from the test vessel with a pipet. .