Reference

Furan and pyran derivatives as modifiers of propylene polymerization catalysts

Furan and pyran derivatives as modifiers of propylene polymerization catalysts. Karayannis, Nicholas M.; Lee, Sam S. (Amoco Chem. Corp., Naperville, IL 60566, USA). Makromol. Chem., 184(11), 2275-84 (English) 1983. CODEN: MACEAK. ISSN: 0025-116X. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) Studies of various THF and tetrahydropyran derivs. as modifiers of Ziegler-type propylene polymn. catalysts are reported. Among Me derivs., ethers contg. 2 Me substituents on carbon atoms adjacent to the ether O provide the best activity-stereospecificity combinations [e.g., 2,5-dimethyltetrahydrofuran (I) [1003-38-9] and 2,2,4,4-tetramethyltetrahydrofuran (II) [3358-28-9]]. Significantly better stereospecificity with some loss in activity is realized when bulkier ethers such as isochroman (III) [493-05-0] or 2-(tetrahydrofurfuryloxy)tetrahydropyran (IV) [710-14-5] are used. On the other hand, combination of one of the preceding ethers with a second modifier [(Bu3Sn)2S [4808-30-4], (BuO)3P [102-85-2], or tri-Et thiophosphate [126-68-1]] results in catalyst systems characterized by very attractive activity-stereospecificity combinations. Systems of this type, contg. I or II, exhibit higher activity and about equal or better stereospecificity than systems modified with only the second modifier; whereas III and IV depress the activity of the latter systems somewhat but provide substantially improved stereospecificity. The steric and electronic effects introduced by the ether modifiers in the single and binary modifier systems investigated are discussed.

Organic solvent for secondary lithium battery electrolyte

Organic solvent for secondary lithium battery electrolyte. Tobishima, Shinichi; Okada, Takeshi (Nippon Telegraph and Telephone Public Corp., Japan).Several substances are used for example 96-48-0 and 1003-38-9 which are their cas registry numbers. Jpn. Kokai Tokkyo Koho JP 61239572 A2 24 Oct 1986 Showa, 4 pp. (Japan) CODEN: JKXXAF. CLASS: ICM: H01M010-40. APPLICATION: JP 85-78484 15 Apr 1985. DOCUMENT TYPE: Patent CA Section: 52 (Electrochemical, Radiational, and Thermal Energy Technology) The solvent is a mixt. of g-butyrolactone (BL) and 31 THF deriv. contg. 31 alkyl substituent. The cond. of 1M LiClO4 in 3:2 (vol.) BL-2-methyltetrahydrofuran (MeTHF) electrolyte, and the charging-discharging efficiency of a cell using this electrolyte, a Pt working electrode, a Li counterelectrode, and a Li ref. electrode were 11.1 ′ 103/W-cm and 92.5%, resp., vs. 10.9 ′ 103/W-cm and 81.3%, resp. for 1M LiClO4 in BL electrolyte. For 1M LiAsF6 in 1:1 (vol.) BL-MeTHF electrolyte, the resp. values were 12.5 ′ 103/W-cm and 87.8% vs. 11.6 ′ 103/W-cm and 76.6% for 1M LiAsF6 in BL electrolyte. .