I n d . Eng. Chem. Res. 1990,29, 1855-1858
reactivity of the fractions cellulose, hemicellulose, and lignin. Registry No. CoClZ,7646-79-9; COz, 124-38-9; CO, 630-08-0; CH,, 74-82-8; Hz, 1333-74-0; water, 7732-18-5; methanol, 67-56-1; formaldehyde, 50-00-0; acetaldehyde, 75-07-0; acetone, 67-64-1; 2-propanol, 67-63-0; acetic acid, 64-19-7; hydroxyacetone, 116-09-6; propionic acid, 79-09-4; 3-methyl-l-butanol, 123-51-3; 2-furaldehyde, 98-01-1.
Literature Cited Akita, K.; Kase, M. J . Polym. Sci., Polym. Chem. Ed. 1967, 5 (4), 833-844. Antal, M. J., Jr.; Friedman, H. L.; Rogers, F. E. Combustion Sci. Technol. 1980, 21, 141-152. Alves, S. S.; Figueiredo, J. L. J . Anal. Appl. Pyrolysis 1988, 13, 123-134. Barooah, J. N.; Long, V. D. Fuel 1976,55, 116-120. Bilbao, R.; Arauzo, J.; Millera, A. Thermochim. Acta 1987a, 120, 121-131. Bilbao, R.; Arauzo, J.; Millera, A. Thermochim. Acta 198713, 120, 133-141. Broadbury, A. G. W.; Sakai, Y.; Shafizadeh, F. J . Appl. . . Polym. Sci. 1979, 23, 3271. Browne. F. L.:, Tane. W. K. Effects of Various Chemicals on TGA of Ponderosa Pine. Forest Products Laboratory Paper 6, Madison, WI, 1963. Chatterjee, P. K.; Conrad, C. M. Textile Res. J . 1966, 36, 487-94. Font, R.; Marcilla, A.; Verdu, E.; Devesa, J. Znd. Eng. Chem. Prod. Res. Deu. 1986,25, 491-496. Hajaligol, M. R.; Peters, W. A.; Howard, J. B.; Longwell, J. P. Proc. Specialists Workshop on Fast Pyrolysis of Biomass; SERIjCP 622-1096, 1980; pp 215-236. "I
1855
Hajaligol, M. R.; Howard, J. B.; Longwell, J. B.; Peters, W. A. Ind. Eng. Chem. Process Des. Deu. 1982,21, 457-465. Himmenblau, D. M. Process Analysis by Statistical Methods; Wiley: New York, 1970; Chapter 6. Howard, J. B. In Chemistry of Coal Utilization-Second Suplementary Volume;Elliot, M. A., Ed.; Willey: New York, 1981; Chapter 12. Jeeers, H. E.: Klein. M. T. Ind. Enn. Chem. Process Des. Dev. 1985, 124, in-183. Kosstrin, H. Proc Specialists Workshop on Fast Pyrolysis of BiomU S S : SERI/CP 622-1096. 1980 PD 105-121. Leu, J. C. Modeling of the'Pyroly& and Ignition of Wood. Ph.D. Thesis, University of Oklahoma, 1975. Liden, A. G.; Berruti, F.; Scott, D. S.Chem. Eng. Commun. 1988,65, 207-221. Maa, P. S.; Bailie, R. C. The 84th National Meeting AIChE, Atlanta, GA, February 1978. Mack, C. H.; Donaldson, D. J. Textile Res. J . 1967,37, 1063-1071. Nunn, T. R.; Howard, J. B.; Longwell, J. P.; Peters, W. A. Ind. Eng. Chem. Process Des. Dev. 1985a, 24, 836-844. Nunn, T. R.; Howard, J. B.; Longwell, J. P.; Peters, W. A. Ind. Eng. Chem. Process Des. Deu. 1985b, 24,844-852. Scott, D. S.; Piskorz, M. A,; Bergougnou, R. G.; Overend, R. P. Ind. Eng. Chem. Res. 1988, 27, 8-15. Stamm, A. J. Ind. Eng. Chem. 1956,48,413-417. Thurner, F.; Mann, U. Znd. Eng. Chem. Process Des. Deu. 1981,20, 482-488. Tran, D. Q.; Rai, C. Pyrolytic Gasification of Bark. AIChE Symp. Ser. 1979, 75 (1984), 41-49. Urban, D. L.; Antal, M. J., Jr. Fuel 1982, 61, 799-806.
Received for review February 6, 1989 Revised manuscript received December 7, 1989 Accepted April 16, 1990
MATERIALS AND INTERFACES Polysilahydrocarbon Synthetic Fluids. 1. Synthesis and Characterization of Trisilahydrocarbons Kazimiera J. L. Paciorek,* Joseph G. Shih, and Reinhold H. Kratzer Ultrasystems Defense, Inc., 16775 Von Karman Avenue, Iruine, California 92714'
Bruce B. Randolph Technolube Products Company, 5814 E . 61st Street, Los Angeles, California 90040
Carl E. Snyder, Jr. WRDCIMaterials Laboratory, Wright-Patterson AFB, Ohio 45433
Trisilahydrocarbons, a new class of compounds of the general formula R2Si(C8HI6SiR3)2,were synthesized by reaction of alkyllithium or alkylmagnesium halides with the novel bis[8-(trichlorosilyl)octyl]dichlorosilane precursor. By varying R groups from C6 to Clo and by using a combination of different R groups, we obtained a series of fluids of wide liquid ranges. The 40 "C viscosities ranged from 74 to 133 cSt, and 100 "C viscosities were from 12.6 to 20.4 cSt. The fluid with R = n-C8HI7had a pour point of -54 "C and a vapor pressure a t 125 "C of 1.6 X Torr. The newly developed process allows the preparation of fluids with closely tailored properties for application in environments where extremes of exposure conditions are encountered.
Introduction For space applications, liquid lubricants are required which are capable of performance at extremes of temperature, have adequate viscosities and high viscosity indices, possess good lubricity, and are involatile even 0888-5885/90/2629-1855$02.50/0
under hard vacuum conditions. Specifically, extremely low vapor pressure compositionshaving viscosities between 90 and 150 cSt at 40 "C and pour points below -50 "C are needed. The materials currently available f o r these applications exhibit a number of shortcomings. The Fom0 1990 American Chemical Society
1856 Ind. Eng. Chem. Res., Vol. 29, No. 9, 1990
blin-Z, unbranched perfluoroalkyl ether fluids of Montedison (Sianesi et al., 1971) possess the required low vapor pressure and high viscosity index (VI), as well as lowtemperature properties. However, under boundary lubrication conditions (Carre, 1986), these materials were found to undergo degradation due to the inherent reactivity of the perfluoroalkyl ethers with metals (Snyder et al., 1981; Jones et al., 1983; Jones et al., 1985). Hydrocarbons of a molecular weight sufficiently high to exhibit the required low volatility have unacceptably high pour points and actually are solids at room temperature. Fluids derived from poly-a-olefins (Shubkin et al., 1980) have greatly improved low-temperature fluid characteristics, as compared to straight chain hydrocarbons, due to branching and high isomer content, but the presence of tertiary carbon atoms causes lowered thermal and oxidative stabilities. Early work (Petrov et al., 1964) has shown that silahydrocarbons have significantly lower melting points than corresponding hydrocarbons. This concept was successfully employed by researchers a t the Air Force Materials Laboratory in developing monosilahydrocarbonsof tailored properties for specific applications (Rosenberg et al., 1960; Bauri and Tamborski, 1961; Snyder et al., 1982; Tamborski et al., 1983). These materials were shown to be superior to mineral oils and synthetic hydrocarbons in both thermal and oxidative stabilities, as well as viscosity/ temperature behavior. The "plasticizing" or pour point lowering (Petrov et al., 1964) action of silicon in conjunction with the inherent ability to prepare compounds having up to four different alkyl moieties attached to the center silicon atom (e.g., having Me, R, R', and R" present in any possible mix, such as MeSiR,R',R'', ( x y z = 3; x , y, or z having a value from 0 to 31, with each of these acting as an "impurity and melting point depressant" for the others) provides for low pour point or, in the case of very high molecular weight materials, for liquids at room temperature. Unfortunately, as can be deduced from Petrov's data and as substantiated by others (Tamborski et al., 1983), the longer the alkyl chains are the higher the pour (melting) point becomes because the effect of the single silicon atom is diluted by the length of the hydrocarbon chains. Consequently, monosilahydrocarbons containing -90 carbon atoms, believed to be necessary with regard to molecular weight to assure low volatility, would be expected to be solids at room temperature. On the basis of the above considerations, it is apparent that more than one silicon atom must be incorporated into each molecule to develop a fluid having the desired viscosity/temperature, low volatility, and low pour point characteristics (Paciorek et al., 1988). We report here the synthesis and characterization of a trisilahydrocarbon family of compounds. The terminology, trisilahydrocarbon, is derived from that of monosilahydrocarbons, which defines compounds represented by the structure SiR,.
+ +
Experimental Section General Procedures. Operations were carried out either in an inert-atmosphere enclosure (Vacuum/Atmospheres Model HE-93B), under nitrogen bypass, or in vacuo. Infrared spectra were recorded on a Perkin-Elmer Model 1330 infrared spectrophotometer as capillary and 0.5-mm films. Molecular weights were determined in benzene with a Mechrolab Model 302 vapor pressure osmometer. The mass spectra (EI) were obtained by using a Du Pont Model 21-491B spectrometer attached to a Varian Aerograph Model 2700 gas chromatograph equip-
ped with a flame ionization detector and a Du Pont 21-094 data acquisition and processing system. Gas chromatography was performed by employing either a 10 f t X 1/8 in. stainless steel column packed with 4% OV-101 on sO/l00 mesh Chromosorb GAW or a 3 ft X 1/8 in. stainless steel column packed with 3% Dexsil300 on 100/120 mesh Chromosorb WAW and using a programming rate of 8 "C/min from 35 to 300 "C. Thermal gravimetric analyses were carried out under reduced pressure (-0.45 mmHg) from room temperature to 550 "C at 10 "C/min with a Du Pont 990/951 system. Vacuum line techniques were utilized where applicable. Kinematic viscosities were determined a t 40 and 100 "C per ASTM method D445 with Cannon-Manning Semimicro viscometers. Materials. Hexachloroplatinic acid (H&C&), 1bromodecane (CloHzlBr),hexyl- and octylmagnesium bromides, and methyllithium were purchased from Aldrich Chemical Co., Milwaukee, WI, and used as received. Dichlorosilane was purchased from Petrarch Systems and purified by vacuum line fractionation. Trichlorosilane and 1,7-octadienewere purchased from Aldrich Chemical and purified by vacuum line fractionation. Di(7-octenyl)dichlorosilane,C12Si(C6H,2CH=CH2)2 (I). To a 100-mL glass ampule equipped with a magnetic stir bar was added hexachloroplatinic acid (H2PtC&,0.15 mL, 0.090 M in 2-propanol) in an inert atmosphere enclosure. After attachment to the vacuum line and removal of the solvent, 1,7-octadiene (14.39 g, 130.6 mmol) was condensed in at -196 "C, followed by dichlorosilane (2.08 g, 20.8 mmol). The ampule was sealed, placed in an oil bath, and heated to a final temperature of 60 "C, at which it was held for 120 h. After the ampule was opened on the vacuum line, no noncondensable material was observed. Excess 1,7-octadiene was evaporated to yield 6.02 g (90%) of I, bp 114-115 "C/O.OOl mmHg. The GC analysis of the product showed a purity of >95% as determined by area percent: mass spectrum (70 eV) m / e (relative intensity, ion) 320 (38.5%, M), 209 (28.0%, M - C8H15), 167 (83.4%, C12SiC5Hg),139 (46.0%, SiC12C3H5), 99 (34.770,SiC1,H). 41 (10070, C3H5). Bis[8-(trichlorosilyl)octyl]dichlorosilane, C1,Si(C8H16SiC13)2 (11). To a 100-mL glass ampule equipped with a magnetic stir bar was added hexachloroplatinic acid (0.05 mL, 0.090 M solution in 2-propanol). Following removal of the solvent on the vacuum line, di(7-octeny1)dichlorosilane (6.02 g, 18.7 mmol) was added in an inert atmosphere enclosure. Subsequently, trichlorosilane (29.9 g, 198.6 mmol) was condensed in vacuo into the ampule held at -196 "C. The ampule was sealed, placed in an oil bath, and heated a t 110 "C for 24 h. Next, the excess trichlorosilane was removed by distillation to yield 10.53 g of 11, bp 224-229 "C/O.OOl mmHg, 94.9% yield. The GC analysis of this product showed it to be >96% pure by area percent: mass spectrum (70 eV) m / e (relative intensity, ion) 553 (5.7%, h'f - Cl), 343 (80.7%, M - C8H16SiC1,), 345 (loo%, isotope cluster for 343), 167 (68.870, C12SiCSHg), 139 (28.0%, C1,SiC3H5), 133 (56.4%, SiC13). Bis[8-(trimethylsilyl)octyl]dimethylsilane, (C(111). In an inert atmosphere H,)zSi[C8H,6Si(CH3)3]~ enclosure, bis[8-(trichlorosilyl)octyl]dichlorosilane (5.00 g, 8.45 mmol) was placed in a 100-mL round bottom flask equipped with a Claisen adaptor, reflux condenser, rubber septum (for needle transfer), magnetic stir bar, and nitrogen bypass valve. After the mixture was removed from the inert atmosphere enclosure and cooled to 0 "C, methyllithium (58 mL, 1.4 M solution in diethyl ether) was added via syringe over a 15-min period. A powdery white precipitate, LiCl, appeared immediately. The mixture was
Ind. Eng. Chem. Res., Vol. 29, No. 9, 1990 1857 same method as that used for the preparation of VI1 was allowed to stir at room temperature for 17 h. Subsefollowed by reacting bis[8-(trichlorosilyl)octyl]dichloroquently, it was cooled to 0 "C, and hydrochloric acid (150 silane (11) (40.0 g, 67.5 mmol) with an equimolar mixture mL, 1.2 N) was cautiously added while stirring vigorously. of n-octylmagnesium bromide and n-decylmagnesium Additional diethyl ether (100 mL) was then added. The bromide in tetrahydrofuran. Workup and purification organic layer was separated, washed with water, and dried yielded 68.6 g of VIII. over anhydrous magnesium sulfate. Removal of the solvent gave 3.41 g (94.5%) of bis[8-(trimethylsilyl)octyl]diResults and Discussion methylsilane: bp 129-133 "C/0.001 mmHg; mass spectrum (70 eV) m / e (relative intensity, ion) 413 (3.295, M - CH3), The trisilahydrocarbon system was chosen for investi243 (89.3%, M - C8H16Si(CH3)3), 169 (76.9%, gation because it appeared to have the potential for (CH3)2SiC8H15), 155 (10070, (CH3)2SiC7H13), 59 (84.670, yielding very low vapor pressure fluids without sacrificing (CH3)&ZH). the exceptional viscosity/ temperature characteristics of Bis[8-(t rihexylsily1)oct ylldihexylsilane, (C6H13) 2monosilahydrocarbons or compromising thermal stability or pour point. The general structure envisioned, namely Si[CBH16Si(C6H13)3]2 (IV). To a 2000-mL three-necked round bottom flask fitted with a reflux condenser, rubber R septum, nitrogen bypass valve, magnetic stir bar, and an I R3Si(CHz)x- Si(CH2)#R3 addition funnel containing bis[ 84trichlorosilyl)octyl] diI chlorosilane (11) (50.0 g, 84.4 mmol) was added tetraR hydrofuran (200 mL) and hexylmagnesium bromide (700 wherein R is an n-alkyl group, containing from 1 to 1 2 or mL, 2.0 M solution in diethyl ether). The latter was ineven more carbon atoms and x can be from 2 to 12, held troduced via a double-tipped needle. To the vigorously furthermore the promise to permit ready tailoring of fluid stirred mixture was added dropwise, over 30 min, bis[8properties by incorporating more than one type of R group (trichlorosilyl)octyl]dichlorosilane. This was followed by or two different alkylene bridges between silicon atoms. a gentle reflux over a period of 7 days. Subsequently, at Bis[8(trichlorosilyl)&yl]dichlorosilane(11)was selected 0 "C hydrochloric acid (1200 mL, 1.2 N) was cautiously as the common precursor of the fluids to be studied. It added. After the hydrochloric acid addition was comwas prepared by the sequence pleted, the aqueous layer was extracted with diethyl ether (2 X 100 mL). The combined ethereal fractions were dried C12SiH2 + CH2 =CHC&i&H =CH2 over magnesium sulfate, and the solvent was removed to yield 81.9 g (95%) of crude bis[8-(trihexylsilyl)octyl]diH2PtCL hexylsilane (IV). This crude product was purified by column chromaC12Si(C&!12CH =CH& (0 tography over silica gel using hexanes as eluant, giving 71.1 CI3SiH. H2PtCI, g (83% yield). The material was further purified by using a falling film distillation apparatus operated at 0.001 mmHg of pressure. A total of 51.5 g of IV was obtained C~~S~(CBH~~S (10 G~~)Z after this procedure, free from volatile impurities. The employment of chloroplatinic acid in hydrosilylation Bis[8-(trioctylsilyl)octyl]dioctylsilane, (C8H17)2Si- reactions has been well documented (Speier, 1979), and [C8H16Si (C8H17) 3]2(V). The preparation of bis [8-(triby use of a large excess of the diene addition to both double octylsilyl)octyl]dioctylsilane (V) was accomplished in esbonds was essentially avoided. In the next step, an excess sentially an identical manner as that described for bisof the trichlorosilane was used, giving a nearly quantitative [8-(trihexylsilyl)octyl]dihexylsilane (IV) by employing yield of compound 11. Thus, the overall yield of pure bis[8-(trichlorosilyl)octyl]dichlorosilane (108.8 g, 183.7 product in the two-step sequence was 89.7%. mmol) with n-octylmagnesium bromide (1600 mL, 2.0 M The development of a high-yielding route to precursor solution in tetrahydrofuran). After purification, 109.3 g I1 allowed the synthesis of a series of compounds of the (50% yield) of bis[8-(trioctylsilyl)octyl]dioctylsilane (V) general formula R2Si(C8H16SiR3)2, wherein the alkyl subwas obtained. stituents can be all the same or different. This was acBis[8-(tridecylsilyl)octyl]didecylsilane,(C10H21)2-complished by using a single reagent or a mixture of or(VI). The procedure employed for Si[C~H,6Si(CloH21)3]2 ganometallic reagents, e.g. the preparation and purification of bis[8-(tridecylsilyl)octyl]didecylsilane was the same as that described for IV, except that in this case the Grignard reagent, n-decylmagnesium bromide, was prepared from magnesium metal The specific materials produced are listed in Table I. turnings and n-bromodecane. Use of the preformed nThe first member of the series, (CH3)2Si[C8H16Si(CH3)3]2 decylmagnesium bromide (1.89 mol) and bis[B(trichloro(1111, could be readily and fully characterized since it was silyl)octyl]dichlorosilane (70.0 g, 118.2 mmol) gave, after sufficiently volatile to be purified by distillation and workup and purification, 159.2 g (94% yield) of bis[8amenable to GC and GC/MS analysis. The mass spectral tridecylsilyl)octyl]didecylsilane. breakdown pattern fully supports the designated rearMixed c6-cB Alkyltrisilahydrocarbon (C6HI3),,- rangement, proving the feasibility of extending this concept to higher molecular weight materials. (C8Hl7)2-nSi[C8Hl6Si(~6~l3)m(~B~l7)3-ml2(VII). The preparation of VI1 was accomplished by reacting bis[8The absence of volatile impurities in the fluids syn(trichlorosilyl)octyl]dichlorosilane(11) (40.0 g, 67.5 mmol) thesized was determined by GC analysis of a solution of with an equimolar mixture of n-hexylmagnesiumbromide exactly known concentration of the trisilahydrocarbon in and n-octylmagnesium bromide in tetrahydrofuran. Othtetradecane (C14H30). The trisilahydrocarbons, with the erwise, the procedures and purification were identical with exception of 111, do not elute from the GC column under those described for IV, giving 41.8 g of VII. the conditions used. Thus, the absence of peaks, other Mixed CB-Clo Alkyltrisilahydrocarbon (CBH17)"- than the tetradecane peak, in the chromatogram was taken ( ~ 1 0 ~ 2 1 ) 2 - n ~ ~ [ ~ 8 ~ 1 6 ~ ~ ( ~ 8 ~ 1 7 ) m ((VIII). ~ ~ O ~ ZThe 1 ) 3 - m ~ as Z evidence for the absence of volatile impurities in the
1 J
1858 Ind. Eng. Chem. Res., Vol. 29, No. 9, 1990 Table I. Trisilahydrocarbon Properties and Characterization Data general formula
MW calcd exptl
compd
calculated assuming equal amounts of each alkyl group.
.
WI
*. u
9
;:
90
80
-
N
io . 60
50
-
.
40
-
30
.
20 10
.
-
c
.
m
24
mmHd
loss, "C (-0.45
"He)
Acknowledgment
.-L_-
is
(-0.45
50% wt
thermal and oxidative stabilities directly comparable to those of the monosilahydrocarbons and are amenable to formulation with commercially available additives. In view of these excellent properties, the trisilahydrocarbons offer a potential lubrication system for the demanding conditions of the space environment.
VI
'2
viscosity,O cSt 40 "C 100 "C VI
wt loss onset, "C
32
,
40
48
,
____-_ 56
i +
64
7Za
80
88'
96
104
TOTAL N W E R OF CARBON ATOMS
Figure 1. Viscosities of trisilahydrocarbons a t 40 and 100 "C as a function of total carbon number. (a) Average carbon number assuming equal amounts of each alkyl group in compounds VI1 and VIII.
trisilahydrocarbon. The infrared spectra of the fluids, as well as the results of the molecular weight determinations, are in full agreement with the postulated structures. It is clearly evident from the compilation given in Table I that materials as represented by compounds IV-VI11 provide fluids of specific viscosity/ temperature characteristics which do not lose weight and, therefore, are not volatile below 200 "C a t pressures of -0.45 mmHg. Of particular interest are the viscosity indices for this family of compounds which were found to be in the vicinity of 170; although not as high as those of Fomblin-Z type materials, they are significantly higher than the values for hydrocarbons. Another aspect worth emphasizing is the low-temperature behavior of the fluids; even the highest molecular weight material, VI, exhibited measurable viscosity at -40 OC. The approach illustrated by precursor 11, Cl2Si(CEHl6SiC13)2,is not limited to the CBH16 bridging groups. Potentially, incorporating other or, in particular, dissimilar bridging groups will extend further the versatility of the derived fluids. As is evident from Figure 1even in a system limited to a certain degree by the two C8H16bridges, compositions can be tailored with specific rheological characteristics within rather wide limits by varying and mixing the R substituents in the general formula R2Si(C8HI6SiR3)2. Summary A series of trisilahydrocarbons of the general formula R2Si(C8H16SiR3),can be prepared by the reaction of the novel intermediate C1,Si(C8Hl6SiC1,), with various organometallic reagents. The rheological characteristics can be readily varied by appropriate combination of the substituents on the silicon atoms. Fluids have been thus synthesized which possess wide liquid ranges, are functional below -40 "C, and do not evaporate in vacuo at temperatures as high as 285 "C. These materials exhibit
This investigation was supported by the Air Force Materials Laboratory, Wright Research and Development Center, through Contract F33615-87-C-5328. The technical assistance of M. A. Marcelli and L. A. Hoferkamp is gratefully acknowledged. Registry NO.111,119840-14-1; IV,128270-38-2; V, 128270-39-3; VI, 128302-25-0.
Literature Cited Baum, G.; Tamborski, C. Tetraalkylsilanes: A New Class of WideLiquid-Range Fluids. J. Chem. Eng. Data 1961, 6, 142. Carre, D. J. Perfluoroalkylether Oil Degradation: Interference of FeF3 Formation on Steel Surfaces Under Boundary Conditions. ASLE Trans. 1986,29, 40. Jones, W. R., Jr.; Paciorek, K. J. L.; Ito, T. I.; Kratzer, R. H. Thermal Oxidative Degradation Reactions of Linear Perfluoroalkyl Ethers. Ind. Eng. Chem. Prod. Res. Deu. 1983,22, 166. Jones, W. R., Jr.; Paciorek, K. J. L.; Harris, D. H.; Smythe, M. E.; Nakahara, J. H.; Kratzer, R. H. The Effects of Metals and Inhibitors on Thermal Oxidative Degradation Reactions of Unbranched Perfluoroalkyl Ethers. Ind. Eng. Chem. Prod. Res. Deu. 1985, 24, 417.
Paciorek, K. J. L.; Pratt, R. E.; Shih, J. G. Trisilahydrocarbon Lubricants. US.Patent 4,788,312, Nov 29, 1988. Petrov, A. D.; Nironov, B. F.; Ponomorenko, V. A.; Chernyshev, E. A. Synthesis of Organosilicon Monomers; Consultants Bureau: New York, 1964. Rosenberg, H. Groves, J. D.; Tamborski, C. Organosilicon Compounds. 1. Synthesis of Some Long-chain Tetraalkylsilanes. J . Org. Chem. 1960,25, 243. Shubkin, R. L.; Baylerian, M. S.; Maler, A. R. Olefin Oligomer Synthetic Lubricants: Structure and Mechanism of Formation. Ind. Eng. Chem. Prod. Res. Deu. 1980, 19, 15. Sianesi, D.; Zamboni, V.; Fontanelli, R.; Binaghi, M. Perfluoropolyethers: Their Physical Properties and Behavior at High and Low Temperatures. Wear 1971, 18, 85. Snyder, C. E., Jr.; Gschwender, L. J.; Tamborski, C. Linear Polyperfluoroalkylether Based Wide-Liquid-Range High Temperature Fluids and Lubricants. Lubr. Eng. 1981,37, 344. Snyder, C. E., Jr.; Gschwender, L. J.; Tamborski, C.; Chen, G. J. Development of High Temperature (-40 to 288°C) Hydraulic Fluids for Advanced Aerospace Applications. Lubr. Eng. 1982,38, 173.
Speier, J. L. Homogeneous Catalysis of Hydrosilation by Transition Metals. Adu. Organometal. Chem. 1979, 17, 407. Tamborski, C.; Chen, G. J.; Anderson, D. R.; Snyder, C. E., Jr. Synthesis and Properties of Silahydrocarbons, A Class of Thermally Stable, Wide-Liquid-Range Fluids. Ind. Eng. Chem. Prod. Res. Deu. 1983, 22, 172. Received for review March 5, 1990 Accepted May 21, 1990
