Rugged New Polymers Sought - C&EN Global Enterprise (ACS

POLYMERS which do not have the traditional carbon-to-carbon chains have been developed by R. N. Haszeldine of Manchester University, England...
1 downloads 0 Views 410KB Size
RESEARCH

A S H

G R O V E

High-Calcium

Rugged N e w Polymers Sought

LIME

Fluorine chemistry plays a big part in search for better polymers for use under extreme conditions

0néçts ■ industry's

demand for PURITY

• for SERVICE for UNIFORMITY

We invite your inquiry for specifications on Ash Grove graded pebble quicklime and "Kemilime" superfine hydrated lime . . . high-purity, high-calcium chemical limes that offer controlled product uniformity, de­ pendable reaction rates, minimum trace impurities. Write:

ASH

GROVE

LIME & PORTLAND CEMENT CO. 101 West Eleventh - Kansas City, Mo.

APPARATUS ADVERTISERS! Beg,

borrow

or

August, 1959 Analytical

steal

an

issue

of

Chemistry.

Page

2 7 A is MUST reading. Written by a leading a d ­ vertiser, it's a report on how to reach and sell the key technical a n d management personnel

responsible

for

the purchase of apparatus. 40

C&EN

AUG.

3,

1959

IT OLYMERS which do not have the tra­ ditional carbon-to-earbon chains have been developed by R. N. Haszeldine of Manchester University, England. Has­ zeldine has studied monomers which contain A:B-type bonds where either A, or B, or both are atoms of elements other than carbon. The bond may b e similar to the double b o n d between carbon atoms in olefins, o r it may be a polar bond. The elements getting most attention are phosphorous, boron, sili­ con, and nitrogen. The nitroso group, — \ — O , is a good example of a bond being investigated. Compounds such as R—Χ—Ο are hard to get as monomers because they cbmerize to form crystalline solids. But by putting a iluorinated radical (such as —CF ; . ) in place of R, a stable mono­ mer is formed. This can b e copolymerized with other compounds, such as fluorinated olefins, Haszeldine told the International Symposium on Fluo­ rine Chemistry in England. ► Fluorinated C o m p o u n d s . Haszel­ dine says the fluorinated nitroso cornpounds and fluorinated olefins form either oxazetidines or polymers, de­ pending upon conditions. For ex­ ample, at about 8 0 e C , C F : i N = 0 and CF._>=CF.j form the oxazetidine, CF.,—Χ—Ο ! I F..C-CF, * At 0 ° C , a copolymer forms. These polymers are oils, greases, or waxes. But at - 2 0 ° C , C F : , X = 0 and CFo=CF 1 > form a one-to-one co­ polymer which is an elastomer. Al­ though it is not especially heat-resistant, the copolymer remains flexible a t very low temperatures. Analogous reactions occur with related fluorinated, nitroso, and olefinic compounds. Phosphonitrilic fluorides containing u p to 17 (PNFo) units h a v e been made by N. L. Paddock of Albright & Wilson, Oldbury, England (C&EN, April 20, p a g e 5 7 ) . For t h e first time, a series of homologs of exactly known molecular weights can be classified as polymers. This will make it possible to test some of the physicochemical theories relat­ ing polymer properties to molecular weight. Heretofore, observations had

to be made on samples of mixed mo­ lecular weight since polymer chains are seldom the same length. Fluorinated phenyl compounds have been made into fluorinated polyethers by L. A. Wall of the U. S. National Bureau of Standards. Xow, J. C. Tatlow, University of Birmingham, has made the corresponding sulfur com­ pounds, polythiophenyl ethers. Start­ ing material is potassium pentafluorothiophenolate. Potassium fluoride is removed in the reaction. These poly­ mers are not known now to possess any unusual practical properties. Although it hasn't been polymerized, tetrafiuorohydrazine has been prepared by C. B. Colhurn of Rohm & Haas. It is made by pyrolyzing nitrogen trifluoride over a halogen acceptor, such as stainless steel, copper, arsenic, anti­ mony, or bismuth. Colhurn has also made difluorodiazine by a new route: as a by-product of nitrogen trifluorodiazine made by the electrolysis of am­ monium hydrogen fluoride. Natures!' P o l y m e r s . The trifluoroacetyl group will protect the amino group of an amino acid during studies of peptide synthesis. Unlike other groups, it can be removed easily b y al­ kali. F. Weygand of the Technische Hochschule in Munich, Germany, has patented a method for isolating amino acids in large quantities from natural products by fractional distillation of methyl esters of A T -trifluoroacetyl amino acids. T h e di- and tripeptide esters can be sublimed in a high vacuum. A7-triHuoroacetyl amino acid tritylhydrazide is especially valuable because the trityl groups can be removed with acids and the trifiuoroacetyl groups can be re­ moved with alkali. This means there is a possibility of reacting N-trifluoroacetyl amino acid azide with amino acid tritylhydrazide to give N-trifluoroacetyl amino-dipeptide tritylhydrazide. The tritylhydrazide can be lengthened further at either the carboxyl or the amine end. IV-trifluoroacetyl-serine or -threonine compounds lose their trifluoroacetyl groups in mild acid. This is useful in synthesizing seryl- and threonyl peptides. ■

Prepared by U. S. Industrial Chemicals Co.

ADVERTISEMENT—This entire page is a paid advertisement

U.S.I CHEMICAL NEWS AUgUSl

A Series for Chemists and Executives of the Solvents and Cliennical Consuming industries

U.S.I. Names New Manager For Alcohol, Solvent Sales Thomas R. Drinkwater has been named Manager of Industrial Alcohol and Solvents Sales for U.S.I., largest marketer of ethyl alcohol in the U.S. In his new position, Mr. Drinkwater suc­ ceeds Warren E. John­ son who has just been appointed Director of Chemical Sales. Mr. Drink w a t e r _ Λ , worked out of the T. R. Drinkwater company's Chicago Sales office until 1957 when he was made Assistant to the Manager of Alcuhol and Chemical Sales, the position he was holding at the time of this new appointment.

Alcohol Aerosol Formulas P r o p o s e d for Gibberellin Because the remarkable plant growth stimu­ lant, gibberellin, has proven effective in dosages as low as 5-10 micrograms, aerosol dispensing has been suggested as a highly ac­ curate, convenient and economical means of applying the material. Using a meter-type valve designed to release about 100 miili rr rams of formulation containing about 5 micrograms of stimulant, one 3-ounce aerosol container (2 ounce practical fill) could give more than 500 applications. Gibberellin is said to lose its effectiveness gradually in water solutions, and consequently all formulas which have been suggested for the material have been nonaqueous. The fol­ lowing composition for packaging in glass has been proposed: Gibberellin 0.00625 wt. % Surfactant 0.200 S.D. Alcohol # 40. anhyd.-q.s.. 50.00 Propellant 50.00 This composition is among those recom­ mended for packaging in lacquer-lined metal : Gibberellin 0.00625 wt. γο Surfactant 0.2 S.D. Alcohol # 40, anhyd.-q.s.. 20.0 Propellant 80.0

Polyethylene Box-Type

U.S.I. Completes Million-Gallon Concrete Storage T a n k for Phosphatic Fertilizer Solutions O n e of Largest E v e r Built f a r P h o s p h o r i c Acid Storage, T a n k H o l d s 1 % -Month * s Plant P r o d u c t i o n , Is Designed To Increase Supply t o F e r t i l i z e r F o r m u l a t o r s An innovation in phosphoric acid storage tanks — a reinforced concrete struc­ ture \vith a capacity of over a million gallons of phosphatic fertilizer solution —has just been completed at Tuscola, Illinois, site of U.S.I.'s wet-process phosphoric acid plant. This 100 ton-per-day plant serves fer­ tilizer formulators in a 12-state area, and operates under the usual seasonal demand con­ A new process for making vinyl foams has ditions of the agricultural chemicals field. been developed, using sodium borohydride When the outsized storage tank goes into as the blowing agent. It is claimed that the service this month, it will help smooth out the neAv method yields a product with fine, uni­ supply-demand curve both for U.S.I, and for form cell structure, low density and low «com­ the formulators served by the company. The pression set — using simple equipment and tank will increase the plant's storage capacity techniques. In addition, the process is sa5d to by W* months' production, insuring formu­ permit the molding of small, intricate sh-apes lators of a steady supply of raw material for unobtainable previously with vinyl foams. their late winter and early spring compound­ Sodium borohydride, reacted mth ^vater in ing season. a mildly acid medium, gives sodium borate The tank, built by the Preload Company. and hydrogen gas. The gas does the blowing and foaming. Control of the foam depends on Inc. of New York, is one of the largest ever the treatment of the borohydride before it is constructed for phosphoric acid storage, meas­ incorporated into the plastisol. and on the uring 100 feet in diameter by 21 M> feet high. choice of activator promoting decomposition. It is made of reinforced concrete which was Heat and plasticizer viscosity are claimed built up in place on a wire mesh form and to have no effect on cell size, eliminating the pre-stressed in the construction. This is an need for foam or heat stabilizers. Ultimate innovation in tank design, since most phos­ foam density depends only on borohydride phoric acid storage is in lined steel tanks. concentration, which runs about 0.4%. Foams P h o s p h o r i c as Fertilizer M a t e r i a l can be formed at room temperature o>r aiiove. While wet-process phosphoric acid has been Setting, on the other hand, requires a 350°F temperature. When the plastisol expands at an intermediate in triple superphosphate pro­ room temperature, cell structure is said to duction for many years, its use as a raw mate­ remain unchanged through the fuse and cool rial for mixed fertilizer generally dates back only to 1957. That use is growing rapidly for cycle. Sodium borohydride is made by reacting a number of reasons: It is the only commer­ hydrogen gas with metallic sodium dispersed cial source of P2Or. in liquid form, which in mineral oil to form sodium hydride, and eliminates dusting and the then reacting this compound with methyl problems of handling solids. It Κ Λ Ι · 1 is by far the most highly acid borate.

Sodium Borohydride To New Vinyl Foam

Is ICey Process

Used for New Mixer-Settler

The recently-reported development of a polyethylene, box-type, mixer-settler extractor — one of the first complex pieces of process equipment made almost entirely of polyethyl­ ene — points the way to still greater utiliza­ tion of this tough, corrosion-resistant plastic as a material of construction for the Chemical Process Industries. This piece of equipment was designed to handle corrosive chemicals used in the sepa­ ration of materials by liquid-liquid extraction. It is a horizontal contactor in the form of a rectangular box about nine inches high. The box is divided into sections, each of which handles a stage in the extraction proc­ ess. Each section contains a mixing chamber suspended in an antechamber, and a settling

1959

Mid-June construction photo of U.S. 3.'$ million gallon phosphoric acid storage tank.

A D V E R T I S E M E N T — This

entire

page

is a paid

Prepared

advertisement

by U. S.

Industrial

Chemicals

U.S.I. CHEMICAL NEWS

August

Storage

CONTINUED-

Tank

source, and the most concentrated source (52-54%), of PaOr, available commercially. Finally, it can be a very economical source of P-O.-.. depending οΐι location. Because of these characteristics, wet-process phosphoric acid offers fertilizer formulators several important advantages: large quantities of ammonia can be neutralized, because of the high acidity characteristic. High analysis grades can be formulated because of the high concentration characteristic. And for granular goods, this raw material gives rugged gran­ ules, well suited to subsequent handling, without the addition of granulation aids. Now. with the addition of large-scale stor­ age facilities, the U.S.I, plant at Tuscola will be better able to handle the growing demand for this economical raw material by formulators in its market area.

Polyethylene Extractor

CONTINUED

chamber. Underflow and overflow ports con­ nect the sections, for flow from stage to stage. The box — and the partitions which sepa­ rate the sections and the settling and ante­ chambers within the sections — are made of polyethylene sheets. Each side of the box is one piece, as is the entir~ bottom. After assem­ bly of box and partitions, all joints were rein­ forced and made water-tight by welding with molten polyethylene. Mixing ciiamueib aie made iiom polyethyl­ ene cups, and polyethylene tubes welded to these cups act as inlets and outlets. E^ch mixing chamber contains an impeller assem­ bly, consisting of s"- ~si mounting plate, stain­ less steel bearing, polyethylene-coated stain­ less steel shaft and a polyethylene impeller.

f

D i a g r a m courtesy I o w a State College, A m e s , ia.

Three U.S.I. Sales Offices Get New Managers Edward C. Richard­ son h a s b e e n a p ­ pointed U.S.I. Chica­ go S a l e s D i v i s i o n Manager, succeeding G e o r g e H. S t a n t o n who has been named Director of Field Sales for the company. Mr. Richardson has been Sales Division Man­ ager for U.S.I.'s Bos­ ton office since 1950. He has been with the company's sales or­ ganization since 1940. Jesse H. Hallowell succeeds Mr. Richard­ son as U.S.I. Boston Sales Division Man­ ager. He ha* been with the c o m p a n y since 1953, first at the Tuscola, 111. plant and most recently at the Chicago Sales office. John A. Putnam, formerly U.S.I, sales­ man in the Atlanta, Ga. area, has been pro­ moted to Manager of U.S.I.'s Atlanta office.

ATTENTION: Of Industrial