POSSIBILITIES FOR EXPANSION OF THE BIPHENYL ?5 PRODUCT LINE 4? Q. E. Thompson Aside from itself, the principal Monsanto products in the biphenyl line are the Aroclors. All others in com- parison are of small volume.' The present line can be diagrammed as follows. benzene Minor Products "Major" prod. Linc isopropyl biphenyl Aroclor 12-?series Hy?:?g?gazgd ter?Eenyl;L?El??hEgroclor 54?-series MCS 460 higher polyphenyls Montgr 9 bis heno bi hen 1 Aroclor 1232 (T?ermi?gl 3 In view of a possible decline in Aroclor usage, oppor- tunities for expanding the biphenyl line in other direct- ions need to be explored. Such other directions may include new uses of biphenyl itself, expand usefulness of various biphenyl derivatives and finally modify the benzene biphenyl process so that more terphenyls are pro- duced, and expand uses of these products. 1. Modifying BiphenleTerphenyl Process Considering the last of the above mentioned avenues first, this approach seems to be the direction of most current promise. Terphenyls and products derived therefrom appear to be increasing in demand or at least have evident potential. An experimental pro- cess study is Just getting underway at Anniston. 0b- Jectives include finding better ways of increasing the terphenyl/biphenyl ratio, and new promoters will be examined. Oxygen-containing additives such as methanol, 2-pr0panol and acetone are currently employed, and a reactor temperature of approximately is required. In this connection, recent results reported by Fields and Meyerson (1) indicate that nitrobenzene is a better promoter and it allows the thermal process to be run at Additional details of this work are given in NEV 036232 MApp?hdix I. Since the probable sequence of reactions is that shown below the possibility N0, glow. um HNQ of using meta-dinitrobenzene and obtaining m-terphenyls directly suggests itself (2). The economic?benefit of this approach may be open to question, however. Biphenyl Derivatives While chlorinated biphenyls are the only important commercial derivatives, certain other substituted bi? phenyls have received some commercial attention, both within and ex-Monsanto. Thus, 4-hydroxyldiphenyl reacts with formaldehyde to give a resin used in wear-resistant surface coatings. This phenol is produced by the sulfonation of diphenyl followed by sodium hydroxide fusion or, along with 2-hydroxydiphenyl as a by-product from the hydrolysis of chlorobenzene with aqueous sodium hydroxide. 2-hydroxydiphenyl, particularly as its sodium salt, is used as a preservative, a germicide, or a fungicide. may be produced by sulfonation followed by sodium hydroxide fusion. Diphenyl may be nitrated readily and the nitrodiphenyls reduced to produce analogs of aniline. The benzidine (qv) is an important dye intermediate. Diphenyl may also be alkylated and sulfonated to produce wetting agents. or the alkyl biphenyls, isopropyl biphenyl has the most attractive fluid properties, and when reduced to isopropylbicyclohexyl, serves as a diluent in tractive oils. Presumably isOpropylbiphenyl could be utilized in a cumene-phenol type process to afford hydroxybiphenyls. Excellent lists of polyphenyls and with certain of their physical properties have been compiled by Malcolm McEwen (3). Parts of these are given in Appendix II. uev 05?233 ?4 3. Uses of Biphenyl Itself Currently diphenyl is used primarily as a heat transfer medium. Its eutectic with diphenyl ether is marketed as Dowtherm A in this country and Diphyl in Europe. Monsanto has served a limited reactor coolant market with biphenyl- mixtures. More recently diphenyl has found application as a dye-carrier for polyester fibers and some 20M lb/year are said to be consumed in this application. Internally we have eXperimented with diphenyl-phenylsulfide mixtures as possible competition for Dowtherm A. Unfor- tunately only about 10% biphenyl can be used and at this level provides no significant advantage over phenylsulfide alone. A more promising composition or the Dowtherm A type consists of bi henyl Gv28%), diphenyl ether and Santowax WR Santowax HR is a terphenyl-higher polyphenyl mixture obtained from Santowax by removing a major portion of the benzene?insoluble and higher polyphenyl isomers. A summary of various biphenyl eutectic mixtures is included in Appendix II. For those interested in additional details, a reasonably up?to-date review of biphenyl and terphenyl cEemical technology is given in by Hubbard and Poffenberger December 29, 1969 References: l. E. K. Fields and S. Meyerson, Accounts of 273(1969). 2. George Urry Monsanto consultant 3. M. McEwen, "Organic Coolant Data Book," Technical Publication July 195 . N. Poi?fenberger and H. L.'Hubbard in Kirk-Otmner's of Chemical Technology, 2nd Ed. Vol. 7. p. 191-204, NEV 036234 i K. FIELDS AND S. Marnason Reaction of Nitrohenzene with Benzene The Cali; ion or radical is therefore the major primary decmnposition product from nitrobcnzene both under electron impact and in thermolysis. This conclusion led us to investigate reactions of nitrobenzene with other aromatic compounds at. 600?. Benzene alone under these conditions, 600? and 9-see contact time, was almost. all recovered; it gave only 0.01 wt of bi- phenyl. with benzene gave the products shown in Table IV. Phenol is a minor product, sug- gesting that the decomposition of nitrobenzcne to phony] radical and nitrogen dioxide is unimolecular, but that the nitro-nitrite rearrangement. may be of higher order. The yields of products are considerably di?erent for the reactions at the two different. concen- tration ratios, and thus give a clue to the mechanism of biphenyl formation. The increasing proportion of bi- phenyl with decreasing concentration of nitrobenzene (yields based on moles of nitrobenzene) implies that most of the biphenyl arises by reaction with benzene rather than by dimerization of the phenyl radical from nitrohenzene decomposition. At a nitrobcnzene:bcn- zenc moie ratio of 1:5, the yield of biphenyl and ter- phenyl combined, as measured by gas chromatography, was 85 mole based on 1 mole of phenyi radical pro- duced per mole of nitrobcnzene decomposed. At a mole ratio of I :25 the yield on the same basis jumped to 170 Both the phenyl radical and the nitrogen di- oxide from the nitrobcnzene may have been involved. The probable sequence of reactions is given in Scheme 1v. Scheme IV N0: onw- tic?+00% gases from the reaction of nitro'benzene with ben- zene consisted almost entirely of NC, with small amounts of CO, N30, Ng, and Hg. The NO. fragment of the nitrohcnzene molecule apparently ends up chie?y as nitric oxide, either by direct reduction or via a series of free-radical hydrogen abstractions and decom- positions? Amt-radix 3: NO. R- ZHNO. ILO Table IV Reaction of Nitrobenzene with lienzene' Relative I'l- Product Phenol lids ?25 0'3 1 ip enyl . Dibcnzoiuran i 10(1) Phenyl ether, hydroxybiphonyl 3 4 '1 . 4 23 Phenyidibenzoiuran 7 .3 Phony] diphenyi ether 1 .0 . Quaterphenyl 8'2 2 Diphenyldibenxoturan .8 ether 0:3 Quinqacphenyl 0 9 Triphenyldibenrofuran 0:3 At 600?, contact time 9 see, total pressure 1 atm, as were all pyrolyses described in this article. 'Rclative intensity of the parent peaks of components in the low-voltage (7.5 un- corrected) masa spectra normalized to bipheayl 100. 'Mole . ratio. NEV 036235 Appendix \l ORGANEC CQOLANT DATABOOK TECHNICAL PUBLICATION N0.AT-1 JULY. 1958 Compiled by: MALCOLM MONSANTO CHEMICAL COMPANY Organlc Chemicals Dlvlalon I Development Department Lindbergh and Ollve Siren! Road St. Louis 24. Missouri NEV 036236 GENERAL PROPERTIES (CHAIN-TYPE POLYPH ENYLSI Mellinq Boiling MrHinq Boili- Moloeulat Poh? Poinl Point Poir COMPOUND Fotmulb Weigh} 0C. Biphenyl C.an I542 09.050 in 254.9 (30: us}; ?Tn- Torphonyl. o- CnHu 230.3 112 133. . - up (I mphenyl. rn- 87.45 Ho) 1? '63: Tuphonyl, p- 212.7 (lo) :55 2'15"" 725?: Quaiatphanyl. 0.0- CnHu 306.4 HE 120 [31 _245_m__ {qu- Qu?etphanyl. m.rn- 85 4" -330 I Oualorphonvl. o.m- [9113} Oualarphonyl. p.p- 3l8 520 604 958 nup- gig-Ill u- 5'-phonyI-m-Iurphonyl I733 "14.5. Quinquophanyl. m.m.m- ?3an 332.5 36 Ouinquophonyl. 392 353 J.) H- 1201 p.l'n.u- [44.54455 (3) Quinquophonyl. p.m.p- 364-66119? _5o_7_-11 p.rn.m- [313) Ouinquuphanyl. o.m.o- Quinqutphonyl. m.m.o- 233-217 Quinquophenyl. p,p.m- JET-70 9 5 317-73 ?51332 I904 37-1-1? Huaphonyl. 0.0.0.0- 453.6 185 $3.62 P.P.P.P- 470 Huaphanyl. p.b.o.p- I85 365 H-nphonyl. m.m.m.m- 251-53 434-33 H.pI.pl .nyI' p- bar-un- 19) 340-1? 210-32 400'1'm'" 446-50 745 Oclaphonyl. m- CnHu ?0.75 w_ 340 658 Nonaphenyl. m- Can 686 I66 (.1) lil_ JIa-l?? 604 a m- Can 762 I84 363 Unde?phonyl. m- I 33B 20? 3% rn- Ch-Hp 9H 22) 433 Itodcciphenyl. I'll.- 990 245 47] Oualluordociphonyl. rn- C-an I066 370 (ll 518 Ouindaciphep?. m- CnHu 292 558 ?In 3? MD Sadnciphonyl. m- C. H.- NEV 036237 GENERAL PROPERTIES POLYPHENYLS) Malling Boiling Mollinq Bu Molecular P'oinl Poinl P- COMPOUNO Formula Weigh! CC. Moihylbiphanyl. 2- 255 31 4 CuHu 159767 ll}I 5 20 Caan I525 265 2 5 Eihylbiphonyl2.2- CuHu 152.3 I3 254 64 Si 2.33 Liq. 270 (3) Lin. 5 Liq. 274 Liq4.13 Canu 102.] IZI 292 I3) 250 5! Dimeihylbiphenyl. 2.1- 264 liq. 5: 2.6- Liq. 263 Liq. 5: 3.4- 3] 282 9 5: 3.5- 12 '31 274 II 51 Cal-In 'T'J'mrihylluph'ml. 2.4.5. [95.1 22! La) 41 Propylbiphonyl. 2. CuHu I96.) 277 II 5] 3- Liq. Liq. Pronvlhiphonyl. 4- 40 (I) IN IIOpropylbiphanyL 2- 24 (I) 270 5 lloplopylbiphenyl. 3- - CuHu I96.) 5a 4- 303 5] ?m?phenvl. Minlurn 3 4 ?54 [18) 295 Il_Fll --65 55 n-Bulylbiphanyl. 2- -?l3 29' 8 55 Sec-Buiylbiphon?. 2- a 282 46 54 h?-Bulylbiphonyllul-RulrlbinhenylDi-cihylbiphonyl. a: an na 51 2-molhvl-5- Liq. 269 Liq. 5 Amyll-Im?yl cum. 0 305 32 [25] 5: CuHu 734.3 52 IN: GENERAL PROPERTIES Malling Boiling Mnllinq Boiling Muliculat Pain! Pain! Point Pain! COMPOUND Formula Weigh! 90. 0C. 0F. 0F. Hoxylbiplunyl. 2 HI- CuHu 235.4 ?38 3IB I3) -?36 604 Huylbiphonyl. 3 Inc ?40 (3, 322 ?-40 EmmyainhonyI?Lmhad human) ?3l 330 ?-24 626 Di-n-Buiylbiphenyl. 4.4' .. CnHau 266.4 58 384 I37 323 4.45 Lin. 463 llq. 635 Di-er-I?ulxlhigh?l?Crating 294.5 Liq. I3) 3&0 63_0 Digumlhiphqul . C..H.. 322.5 ?30 375 405.7 --23 436 an? h3gg?l? CuHu 244.3 [503mm 307mm Egi?fl?hl?qyl. 256.3 l3)_ ?shown 9.1..91..nil. C..-H.. 253.3 22a Can 272.4 ?Go-?mm Eilmph-myl. 4.13mi. can 44 lbl'mm (3) 3397-51:? 244.3 '39- 265 m-?lorphonyl. 4-ptopyl- 44 394 ?2 MI hopropylu CnHa 272.4 --8 406 20 762 m-Torphonyi. ll? 243 65 I49 mayl Cr Hg 300.4 IOU 4'5 [35) 73?? [25] 3111.5 230mm" sun-m:- m-Torphl?nyl. anu 348.5 19) 338-40 92- I97 p-Tarphonyl. 3-ma?uyl- CuHu 244.3 I69 337 misteha'tv'dmz?vl: 10' l" 40? p-Tmphunyl. 2.5-dimoihyl- I59 p-T-rphuurl. Can 250.3 MI 249 43l p-anphanyl. CnHu 286.4 ?2 233 p-Torghanyl. 280 536 pd'orphunyl. 394.6 L9) 959 UuHu 334.4 ll! 236 o.o-qualorphonyl. ll! 236 M-quaiorphenvl. 334 613 2-moll1yl__ (3an 320.4 334.4 l5? (Ian! Lhraphunyl. anu 360.4 '52-63 324-?5 036239 NEH GENERAL PROPERTIES (EUTECTIC MIXTURES) Liquid CoTposiIIon Vapor Compoai?on [Incl/J (mo M.P. MIXTURE COMPOSITION hi i 2nd 314! 2nd 37d 03. OF. Rah-rant. 01555571755551.1551?. 57 43 35.5 53.4 39.5 234.5 103 454 (In 40.5 59.5 73.1 20.9 23 205.5 73.4 547 (17) 45 55 42 IOB Biphenyl?p-hrphonyl 97.1 2.3 57.0 154 [101 33.7 66.3 20.? NJ 29.3 345.5 85 654 (In 95.55 4.35 55.5 155.2 1101 35.45 1.55 55.75 132.2 [101 91.7 13.3 59 157 1251 33.7 55.3 57.3 12.7 22.2 253 as 505 1 171 4I.0 2?.0 30.0 33.2 60.0 2342.5 30.? 25.6 85.4 5.3 9.3 25.3 288 7B 550 42.5 37.0 20.4 33.2 54.4 2.4 25.4 242.5 75 45a 1171 3 LI 47.! 2 .0 37.3 9.3 53.4 I048.7 7 .3 20.3 7.9 I 1.9 294 53 55! 30.? 47.5 2L6 NJ 2 L3 4.6 I0.5 237.5 5 563 [11) mph-5111., 40.2 57.2 0.5 73.3 21.0 0.00 22.7 2117 73 543 I 171 5L9 24.5 23.6 I5.2 3.3 81.5 I5.3 229 59 534 [17} 53.2 25.2 21.5 51.7 14.3 23.4 1555.5 33.5 0.7 73.1 20.5 0.3 25.0 345 54 555 {171? 53.4 24.6 22.0 I4.3 79.9 5.3 I53 275.5 62 525-? [In 55.5 33.5 0.7 13.0 05.9 0.04 23.9 253 54 nev 035220