before you commit yourself to a stereospecific catalyst investigate
new Lithium Butyl 1. F i r s t off, l i t h i u m butyl is n o t new. What is new is its commercial availability in a solvent rather than an e t h e r vehicle. Highly stable, i t can be s t o r e d at room temperature for indefinite periods w i t h o u t de terioration. And you can handle it j u s t as freely under nitrogen as u n der argon or h e l i u m .
2. Lithium butyl is a single component catalyst of known composition with ho mogeneous reaction mechanism. Com pared with conventional heterogeneous catalysts of uncertain composition, lith ium butyl permits more accurate pre dictions of final polymer performance . . . makes controls easier t o establish and hold. 3. The a m o u n t of l i t h i u m derived catalyst required in ordered isoprene polymerization i s extremely s m a l l . Possibly less t h a n 0.01% of the iso prene. And t h e a m o u n t of the c a t a lyst remaining i n the polymer i s e v e n smaller . . . of t h e order of parts per million. T h u s , despite its rela tively h i g h price, l i t h i u m contrib u t e s very little t o t h e cost of t h e product. It m a y actually reduce t h e
cost by permitting economical s i m plification of post polymerization t r e a t m e n t of the polymer.
1er type catalysts. An excellent yield of cis-1,4 poly butadiene has been reported as resulting from such a substitution.
4. Little definitive information has been published as to the merits of various catalyst systems in natural rubber syn thesis. Both Ziegler and lithium cata lyzed rubber show approximately the same percentage of cis-1,4 isomer. But there is one product difference. Lithium catalyzed polyisoprene has a higher mo lecular weight than either Ziegler types or natural hevea rubber. Ultimately, the efficiency of the catalyst may depend more on the purity of the monomer than on any other single factor.
7. The commercial future of F o o t e ' s new lithium butyl preparation s e e m s assured. Its potential in or dered polymerization has been es tablished. And n u m e r o u s research projects are focusing o n i t a s a n intermediate. If you'd like to renew your acquaintance with l i t h i u m butyl, just return the coupon, c h e c k i n g your specific interest.
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^W^^Sssm^SSmy^Si^^r^ " VaMMMMMMV * 5. Participants in the 1958 Gordon R e s e a r c h Conference on polymers clearly stated the need for efficient, soluble, stereospecific catalysts i n large q u a n t i t i e s . L i t h i u m butyl s a t isfies all of t h e s e n e e d s .
FOOTE MINERAL COMPANY
U6 Eighteen West Chelten Bldg. Philadelphia 44, Pennsylvania Gentlemen: Please send me the follovvin 8 checked monographs: • 100—Catalytic Lithium r j # ι ο 1—Lithium in Organic Chemistry D # 1 0 3 _ L i t h i u m Butyl ~r • „ _ . . , . : . • #104—Catalytic Lithium in Polymer ization Plus information on • sample quanti ties • commercial quantities Name
6. Lithium butyl has been suggested as a substitute for aluminum alky Is in Zieg-
Company Address
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Circle Nos. 26-1, 26-2, 26-3, 26-4 on Readers' Service Card
VOL. 51, NO. 7 · JULY 1959
93 A
