1298
******
INDUSTRIAL A N D ENGINBERING CHEMISTRY
helpful suggestiOne concerning the standardhtion of the apparatus. The guidance of J. H. Dillon and the continued intercat of J. N. Street in the course of this work is greatly appreciated. Tbe permission of the Firestone Tire and Rubber C o ~ ~ p a ntoy publiah this work is gratefully sclmowledped.
***
VoL 34, No. 11
(8) Gshman, 8. D.,Woodford. D. E.,and Btsmbeugh, R. B., -0.
h. 33. . 1032-8 (1941):
cbm T&..
IND. 14.
(11 (11) Jone 17
(12) K w h . C. W.,h o c . Rubber T& C d . , Lmda,1938, 9871wO; Rubber C h . Tadi.. 12,38143 (1939). (13) W,E.T.,b. EIP((. C m . . ANAL ED.,9, SSZ8 (1937). (14) Macby, J. Q., Anderaon, J. 0.. and Gardner. E. R.. !l+am. I d . R u b k I d . . 18. 123-37 (1840): Fhbber CFtem. T d . . 14.
Literature Cited
(1) B-ett. C.E., h. ENQ.C-., 28,303-6 (1934). (2) Barnett, C. E.,and Matbeas. W.C.. M., 28, 1292-6 (1934): R e C h . Tadi.,8, 138-49 (1935). m L. ~ A LE. ~ .. 5. . . a6o-i (ma: _,rMlur. ---..-. .,v.. IXD.EW. c-.. ~~~~~~~. . .. Rubber Chem Tadi.,7, 125-9 (1934). (1939). (4) Fielding, J. E.,IND.ENQ. CH.Y., 29, 880-5 (1937): Rubber (16) Naunton, W. J. 8.. and Waring, J. R. 8.. Tram. I d . R&r C h . Tadi.. 10,807-18 (1937). I d . . 14, 340-64 (1939): Ru6bsr C h . Tadi., 12. 816-80 ' , L. S., and Dubinker, Y. B.. Caoukhue & Rubbsr (5) (1939). (U. 8. 25-84: Rubbe C h . Tadi.. 13. -~8. RJ. ~ June. ~ , 1939. _ (17) RoeIig, E.. ploc. Rubber Tadi. emf., Ladas 1938. 821-9: 38-74 (1940). Rubbe C h . Tadi.,12,38c400 (1939). (6) FRunldn.L.8.. and Dubink. Y.B.. J . RuMwr I d . (U.8.8. R.), (18) 8sbm.U. L. B.. , and Dinamore. R. P.,India Rubbm W&, 104, ' 13, 132-40. 338 (1986); Rubber Chum. Tadi.. 11, 368-71 46-60 (April. 1941). (1938). 110) Williams, lm Tan. Elm. Cam. 15. 1.54-7 (1923). (7)Gehman, 8. D., J . dppl*dPhys.. 13,40Z13 (1842).
..~
...
~~~
~~~~~
~~~
Effect of .. * * Petroleum Proc
NI
I
Y
EFFECT O F KEROSENES
*
w
r
* *T*
Vulcanizates
he use of the aniline point
has been advocated
as a means of predicting the swelling power of
Donald F. Frsrer E. 1. du Pant de Nemourr & Company, Inc., Wilmington, Del.
N PRECEDING papers of thia series (9, J)it w88 demonstrated that the ViscaSitJI-gravty constant or, preferably, the aniline point of an oil could be used as a criterionof the swelling &ect on neoprene of oils reprenenting a wide ran@ of commercisl pmducte. In the case of petroleum producta similar to kemsene or fuel oil, it hss been found that the aniline point alone is not indieative of the swelling deet. However, as this paper will show, the aniline point oombind with the gravity in the form of the Diesel index will predict the swelling &e& and thus may be used to specify standard immersionmediaofthelenetype. The neoprene cornpasition used was identical with that of
I
lubricating and hydraulic oils on synthetic rubber vulcanizates. This scheme allows a means of describing constant-swelling-effect oils for specikcation purposes and has been used to this end. With kerosenes and kerosene-benzene blends the aniline point does not predict the swelling power. However, the Diesel index, a simple constant involving aniline point and gravity, may be used for this purpose. This allows the replacement of kerosene-benzene blends by constant-swellingeffect kerosenes which will permit the use of higher test temperatures and will eliminate the necessity of reflux condensers during immersion tests.
the previous investigations: 1M) 4
as.8 a 6
ssmplea of this composition were prepared for the volume increaen test as previously d e a c r i i . The physical data for the kerwaea usedin the swelling testa are shownin Table I.
Ala0 shown am the volume inoresse reaulta after immemion of neoprene speoimene in the kemsenea at 27.8', 70°, and 100" C. (W, 168', and 212' F.). The reaulta am t h m of the maximum or equilibrium swelling. The immersions were oontinued for a total of 56 dap, but equilibria bad been esbbhhd, depending on the temperature, in 2 to 7 dap.
November, 1942
***
a
8
4
6 6
7 8
9 10
11
F~T E 2
Damiptim Km-e
1
-
Em-e K-e Em-s K-e H~w&erd #&it. K-ne Emme y & o U Earcaens Kmmm E--
12 ia
.. ..
....
....
-
Gravity (A. P. I.)
lasS
13 to over 100 per ceni at 100" C. Table I shows that the kemmm varied in swelling power from 42 to 83 per cent. Lubricating oils wntgin Bubstantial proportionsof eatumted and unsaturated ring compounds and their presence is indicated by the visoositygravity w n s h t and/or aniline point. Jhrosenb, on the other hand, are p d tected from thermal decomposition during the procesa of manufactum and consist predominantly of chain rather .... than ring structures. This is indicated by the narrow range of properties (such 88 the refractive index) and, probably, by the lack of wrrelation between swelling power and aniline point. The aromatic content of the kerceena waa calculsted acwrdhg to the specific dispersion method of Grosse and Wackher (4), but the resulte obtained did not permit a correlation with swelling power. In petroleum producte such 88 kerosene where there is a predominance of straighbchain or branched-chain Baturated hydrocarbons, the aniline point is stiected considerably by the moleculsr weight of the product. The gravity also is sfiected but in a reverse direction 80 that the product of the two, or Diesel index, becomes essentially indepndent of the molecular weight. while the molecular weight of saturated parsfsns greatly afieate the aniline point determination, the wrrelation of swelling power and aniline point may be made successfully in the w e of heavier oils because of the d e r content of Bsturated par&. h u m s b l y the molecular weight does not greatly ineuemce the swelling power of the petroleum product. ThefactthattheDidindexwiUpredicttheswallingpower of a b e sfiords a ready means of specifying s t a n d d
..
I
From the data in Table I it is obvious that the swelling caused by the kerosene is not a simple function of the refractive index, gravity, or aniline point. However, if the last two wnatanta are combined in the form of the Diesel index (f), Ditaalindex
******
Summary d Dab h Kemama Mu. Vel. Inof Refmotive Aniline A.P.I. Nmp.eno Index Point Qnsi (10. c.) (e F.) (so0 a7.8. c. 709 c. ioo* c. i.uea 1w.a 48.5 66.88 e . 8 56.0 67.1 1.4429 154.5 44.8 69.83 85.8 46.7 57.5 64.79 1.4wB 148.6 48.6 46.8 58.7 71.9 i.4m 140.5 43.8 80.w 5a.a 88.5 8a.4 67.40 67.1 41.8 6S.O 1.4480 151.8 44.4 i.46a7 i5a.i e.8 64.~4 e . 9 56.6 70.2 i.um ia9.6 44.0 61.88 w.9 66.8 8a.e 1 . ~ 9 0 im.7 44.0 67.w 41.7 .m.a m a i.45as 161.6 e.8 64.88 u.6 58.5 70.5 1.4470 188.0 46.8 76.28 .. 49.0 1.46M) 148.0 43.0 w.04 79.0 1 . 4 5 ~ ia9.o 43.1 60.91 90.3 0.6 171.0 46.6 79.B
Table 1.
'
8.mD1e NO.
INDUSTRIAL A N D ENGINEERING CHEMISTRY
vity
(A.P. I.) x
aniline point ('
F.)
1W
-
specisc 141'5 gravity -131.5
it will be seen (Figure 1) that the D i d index canbe wrrelated with the swelling power of the kerc@ane at the three teat temperatma investigsted. The previous paper indicated that the swelling accomplished by 8.A.E.No. 10and 20 lubricatingoils varied from
T
, IO
rn
60
mcacL
IO
IWIX
Figure 1. Correlation of Diesel Index with Swelling Power of Kerosene
*
I
0
I
I
I
2
D""111
Figure Q.
.om?-
WO""1
Drying Curves
.*****
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
immersion media. I n the past a favorite teat medium for synthetic Nbber wmpositions has been an 85-15 blend of kemsensbensene, the teat t e m p t u r e being 57-60" C. (135-140O F.). oriejnslly it pras thought that by using a blend the benaene would compensate for the difference in
***
Vd.3(. No. 11
the interests of accuracy, the drying time should be specified, particularly with blends of high bensene wntent. In Figure 3 is plotted the volume increase us. the Diesel index of the blends. Straight-line relations o m the entire Diesel index range are not obtained for drying times greater than 0.5 hour, because of the greater volatility of benzene as wmpared with keroeene. However, the curves for any drying time are assentially straight lines for blends in the range normally employed. It is reasonable to -me, from Figure 3, that the Diesel index may be used to specify consht-sweUiug&ect kemsenebemene blends by specifying the Diesel index of the component kerosene and the ratio of the blend. However, it is suggested thrit for specification work such blends be eliminated in favor of a single kernsene of de6nite Diesel index. In addition to assisting uniformity, this move will allow the we of higher testing tempemturea and will eliminate the necessity of reflux condensera for most test temperatures. Table II. Ropntiw d Kwosmm-Benzene Blends b e - h m , %by ._. Vol. 1W.O 96d 8616 76-25 0-1W
A. P. I. Qr. (BO* F.) 44.7 44.1 43.8 42.6 29.5
*eyht,
D
l Indsr ~
143.6 137.5 130.0 118.5 8.0
8L.14 (10.04
56.94
€4.36 a.86
In conclusion it is emphasised that test kerosene should be discarded after being used once. The Diesel index and swelling power will be changed by the heat wnditions of the teat and by softenera extracted by tbe kerosene from the composition under test. The variation in physical properties of the kemeene after aging at an elevated temperature is apparent from a comparison of the data in Tables I and III. Similar changeswill alsooccuruponstandingat momtemperatures. Figure 3.
Correlation of Diesel Index snd Swelling Power of Kerosene-Benzene Blends
swelling power of various kerosenea. This is not entirely h e ; in addition, because of the benzene, the drying time must be speci6ed exactly in order to obtain check results. Even more disadvantageous is the fact that it is necessary to use a reflux condenser to prevent the loaa of benzene during the immersion period. Neverthelese, clumsy as it may be, this type of immersion medium may utilise the Diesel index to obtain kerosene-bene blends of constant swelling power. when kermene-benzene blends were investige,ted, the following composition was used since it is more representative of commercial wmpositions than the teat composition used previouEly : IW p.6 4 1M 6 5
After prepmation as previously described, specimen@were immersed in the blends shown in Table II. The immersion bath was opersted at 136140O F., and the tubes c~nbining the fluids were quipped with wndensers. Volume indetermination8 were made at intervals, and it was observed that equilibrium swelling was established between the first snd m u d days of immersion. At the end of 14 days tbe ssmplea were r e m o d and allowed to dry in air at 27.8' C. (82' F.). The drykg c u m (Figure 2) indicate that, in
Tablelll. brnple No.
E l i d o f Aging on Ropntlw of Known.
Oil ' u l
Dhfindex 85.81 88.19 84.80 80.88 67.44
mas
61.82 67.69 M.88
After 66 Dam at Aniline point, ' F. 153.3 42.a 166.6 43.3 159.0 42.1 152.0 42.0 167.8 43.5 153.0 41.6 167.0 43.2 162.5 42.6 168.5 42.4
looo 0. Diad Index 66.80
72.09 66.84
a.84 68.56 85.73 87.83 69. 2a e7.m
In view of the instability of kerosene it would appear to be preferable to adopt an oil rather than a kerosene as a standard immersion medium. This has already been done in one or more cases (6), the oil being specified by the aniline point. The aniline point may be used for petroleum products (oh) having A. P. I. gravities lese than 35; the Diesel index ia necessary for lighter products having A. P. I. gravities greater than 40. Acknowledgment The author acknowledgw with appmiation the suggestions and assistsnce of Creig S. Hoyt, of Grove City C~Uege, Grove City, P e w . Literature Cited (1) (2)
Beoka and FLEher.5. A . E. J m r d . 45.876 (1984). FT-, IND. ENQ.WU.. 32,320(1840).
(4)
C h e s . n d Waakher. IND. EN^. Cmx.,ANAL.ED., 11.614 (1989).
(a), Frmr. Rubba C h . Tscli.. 14, 204 (1941). (6) 8. A. E. J m d . 50.20 OW).
