Table
I X . Rubber-Rich Hycar-Phenolic
Recipe Hycar 1072 Hycar 1042 Durez 12687 Stearic a c i d Zinc oxide TMTD
Blends
100.0
100.0
.....
25.0 2.0 10.0
50.0 2.0 10.0
100.0 50.0 2.0 5.0 3.5
. . . . . . . . ..
.....
.....
All c u r e s 30 minutes a t 310'F.
3970 190 58
2350 490 39
620
470
-
-
-25 -35
-25 - 35
+ 23
+ 17
+ 19
Ultimate t e n s i l e strength, p. s. i. 3700 Ultimate elongation, B 420 Hardness (Duro D ) 42 T e a r r e s i s t a n c e , ASTM D 624, d i e C with grain, lb./inch 440 Low temperature brittleness, 746 ASTM P a s s , F. 60 70 Fail, OF. ASTM oil 3, 70 hours at 300'F., vol. change, %
CEMENTS
Hycar 1072 is readily soluble in t h e usual solvents used in making cements f r o m nitrile rubbers. T h e possibility of a zinc oxide cure of a IIycar 1072 cement s u g g e s t s a method of obtaining a tough, highly abrasion-resistant, unloaded film. Cements made from mixtures of Hycar 1072 and phenolic resins have shown good adhesion t o metals. T h e presence of t h e reactive carboxyl group may suggest unique applications a s protective coatings, caulking materials, or adhesives.
1. T h e oil and fuel r e s i s t a n c e of t h e polymer i s not harmed by t h e p r e s e n c e of the carboxyl groups, in fact, volume change on immersion i n s u c h materials is d e c r e a s e d slightly. 2. T h e inclusion of carboxyl groups in t h e nitrile polymer h a s produced a high gum t e n s i l e strength rubber with high oil r e s i s t ance. 3. R e c i p e s used for standard nitrile polymers are generally satisfactory with Hycar 1072. 4. When a standard nitrile polymer is compared with t h e carboxylic nitrile polymer in identical r e c i p e s , the carboxyl containing polymer exhibits a higher t e n s i l e strength, modulus, h a r d n e s s , compression s e t , tear, not tensile, hot elongation, hot tear, and abrasion resistance. At t h e same time elongation and rebound a r e lower and low temperature b r i t t l e n e s s is improved. 5. T h e hardness of a Hycar 1072 vulcanizate d e c r e a s e s more rapidly than a normal nitrile a s t h e operating temperature r i s e s above room temperature. 6. T h e use of p l a s t i c i z e r s or reduced loading a r e effective methods for reducing t h e hardness of Hycar 1072 vulcanizates. 7. In t h e presence of low amounts of reinforcing agen: Hycar 1072 vulcanizates retain s a t i s f a c t o r y properties and in addition p o s s e s s low temperature b r i t t l e n e s s v a l u e s near 95'F. 8. T h e carboxyl containing nitrile polymer s h o w s unusual properties in b l e n d s with poly(viny1 chloride) and phenolic resins.
-
T h e properties observed suggest application in fields requiring high hardness compounds a t no sacrifice in other properties; u s e in such items a s o i l well parts, shoe s o l e s , an3 belting where higher abrasion resistance would b e valuable; application in such lines a s adhesives, protective films, and prosthetics where a high gum t e n s i l e in addition t o other properties of a highly oil resistant polymer are valuable; u s e in conjunction with resins of various kinds of which poly(viny1 chloride) m d phenolic types a r e typical; and adaptation t o parts exposed t o shock and oil or fuel at very low temperatures. Hycar 1072 (€3. F. Goodrich Chemical Co.), t h e carboxyl containing polymer described, is available commercially.
SUMMARY
LITERATURE CITED
T h e building of carboxyl groups into a nitrile polymer h a s changed many of t h e characteristics of t h e b a s i c polymer from which i t was built. Comparison of t h e carboxyl containing polymer with a similar nitrile polymer devoid of carboxyl groups leads t o t h e following conclusionn:
(1) Brown, H. P. (to 9. F. Goodrich Co.), U. S. P a t e n t
2,724,707
(1955). (2) Brown, H. P., Duke, N. G., Rubber World 130, 784-8 (1954). (3) Brown, H. P., Gibbs, C. F . , Ind. Eng. Chem. 47, 1006-12 ( 1955). (4) Lufter, C. H., Rubber World 133, 511-22 (1956). Received for review May 31, 1956.
Accepted December 5, 1957.
Some Properties of L i g n i t e Creosote S. D. CAVERS', C. C. WALDEN2, and J. H. HUDSON' The University of Saskatchewan, Saskatoon, Sask., Canada
T h e present study concerns an evaluation of properties of creosote derived from Saskatchewan lignite. Additional properties t o those reported by Prostel (8) for North Dakota lignite have been measured. T h e s e include creosote toxicity, t h e effect of chlorination on t h e toxicity, and t h e rate of evaporation of t h e preservative. At Bienfait, Sask., lignite is treated by t h e Lurgi low temperature carbonization process (1,9). T h e maximum temperature in t h e retort is 1290' t o 138O0F. T h e lignite tar i s condensed from t h e g a s stream and is distilled a t atmospheric pressure i n batches. T h e fraction distilling between ' P r e s e n t a d d r e s s , University of British Columbia, Vancouver
a, ,B.c.
P r e s e n t a d d r e s s , British Columbia R e s e a r c h Council, Vancouver 8, B. C. 'Present a d d r e s s , Industrial Minerals Laboratory, Saskatchewan R e s e a r c h Council, Regina, Sask.
304
INDUSTRIAL AND ENGINEERING CHEMISTRY
approximately 325" and 710'F. i s collected a s creosote. Two specimens were considered in the present study. T h e first w a s a representative stream sample from the distillation. T h e second w a s taken f r o m a commercial shipment supplied to Northern Wood Preservers (Sask.) Ltd., Prince Albert, Sask. Except a s noted, t h e standard methods of t h e American Wood-Preservers' Association ( 4 ) were used in obtaining t h e d a t a presented. Toxicity measurements were made by t h e agar flask method (5) a s modified by Finholt (7). P o l y porus tulipiferus (Madison 517) between 12 and 15 d a y s old w a s t h e fungus used for inoculations. In t h e initial s t a g e s of the work fractionations by distillation were made both at atmospheric pressure and under vacuum. However, a s later work showed that distillation at atmospheric pressure did not adversely affect t h e toxicity of t h e preservative, vacuum distillation w a s discontinued. VOL. 3, NO. 2
Table
I.
Table
Properties of Creosote Specimens
Specimen Specific gravity, 38' C./15So C. Water content, wt. 70 Distillation range', 'C. I 0-210 I1 210-235 III 235-270 IV 270-315 V 315-355 Residue Losses Insoluble in benzene, wt. 70 Coke residuec, wt. %
I 0.967 2.4
5.0 21.8 25.9 23.4 12.6 10.gb 1.0 0.22 0.75
Specific Gravity, Tar Acid Content, and Toxicity of Creosote Specimens and Fractions
I1
... 1.6 2.2 10.1 25.5 28.6 18.0 14.9
0.7
...
...
'Per cents by weight on dry basis. For specimen I figures are average values for 8 distillations. bFloat test ( Z ) , 34 seconds. CStandard coal crucible used.
Considerable work h a s been done on chlorine compounds a s wood preservatives (11). In t h e present investigation chlorination w a s carried out by bubbling chlorine through whole creosote or i t s fractions in t h e presence of iron wire, and later washing t h e material with water t o remove hydrochloric acid. An evaporation curve w a s obtained by exposing lignite creosote i n P e t r i d i s h e s in a room at 23' i 2"C., and weighing t h e d i s h e s at periodic intervals up t o 26 weeks. RESULTS AND DISCUSSION
Various properties of t h e c r e o s o t e specimens examined a r e l i s t e d i n T a b l e I. T h e specific gravity of lignite creos o t e is considerably less than that stipulated by ASTM standard D 390-53 (3). T h e specification for water content is met. However, water apparently formed and settled out a t t h e bottom of creosote specimen I. If t h i s water is included, t h e specification is not met. Material insoluble in benzene and c o k e residue f a l l s within t h e stipulated limits, and t h e distillation range nearly falls within t h e limits. Similar results h a v e been reported by Prostel (8) for North Dakota lignite creosote. T a b l e I s h o w s that larger percentages of higher boiling material were found in specimen I1 than in specimen I . T h i s result is consistent with t h e fact that considerable paraffin wax crystallized from specimen I1 at temperatures below about 4 0 ° F . In T a b l e I1 a r e reported t h e s p e c i f i c gravities, t h e t a r acid contents, and t h e toxicity characteristics of c r e o s o t e specimen I and i t s fractions. A few d a t a for specimen I1 a r e included also. T h e apparent inhibition point (AIP) (7), is t h e lowest weight per cent of preservative in t h e maltagar-creosote mixture which will prevent radial growth from t h e fungus transplant onto the surface of the agar mixture. T h e total inhibition point (TIP) (IO),i s t h e minimum weight per cent required to prevent v i s i b l e growth on both t h e poisoned malt-agar and t h e inoculum. T h e killing point (KP) (IO),is t h e minimum weight per cent which will kill t h e fungus a s indicated by i t s failure t o grow when transferred from t h e poisoned t o a n unpoisoned medium. Finholt (7) points out t h a t whereas a l l of t h e above three criteria depend o n the toxicity of t h e preservative, t h e total inhibition point and the killing point depend also on i t s diffusivity in t h e inoculum. Therefore t h e apparent inhibition point being independent of diffusivity, should be a more useful indication of toxicity. To facilitate t h e making of comparisons, data for e a c h of t h e three criteria were obtained i n t h e present work. T h e tar acid contents a r e lower than t h o s e reported by P r o s t e l (8) for North Dakota lignite creosote, although t h e pattern of distribution among t h e fractions is similar. T h e tar acid content of a mixture of fractions I t o V ( 4 ) is l e s s 1958
II.
SP. CS., 380 C . / l S . s b C .
Whole creosote,
0.96fd
specimen I
Whole creosote,
Tar Acids, Wt.% 34b
apecimen I1
Fraction.
OC.. soecimen I I '0-210 . I1 210-235 III 235-270 I V 270-315 V 315-355 Fractions I t o V m i x e d
0.899 0.963 0.967 0.968 0.973
35 51 47 32 28' 33
AIP, Wt.%
TIP, Wt.%
KP, Wt.%
0.O6Sc 0.085 0.090 0.055
0.095
...
0.085 0.055 0.060 0.10 0.095 0.055
0.095 0.055 0.085 0.11
0.095 0.065 0.100 0.16
0.165 0.090
...
0.095
'For whole creosote only a Westphal balance warn uocd. bFor theae fractions only a gravimetric method wan uaed in which t a r . a c i d s were inolnted and weighed a s such. Thls method gave r e s u l t s almost Identical with those obtalned by the AWPA method for fractions 11, I11 and IV. Cw'here three figures are given a f t e r decimal point, toxlcity values are known within approximately f 0.005 or less.
than would b e expected on t h e b a s i s of t h e individual fractions. T h e toxicity values for l i g n i t e creosote satisfy t h e arbitrary criterion of Vaughan (12)that a satisfactory wood preservative s h m l d h a v e a killing point of 0.1% or l e s s . T h e killing point is t h e s a m e a s that reported by Duncan ( 6 ) for creosote from T e x a s lignite. For t h e fractions of lower boiling point (and, presumably, lower average molecular weight) little difference e x i s t s between t h e apparent inhibition points and t h e corresponding killing points. However, for fractions of high boiling point, considerable difference e x i s t s between t h e two v a l u e s b e c a u s e of t h e lower diffusion rate of t h e preservative i n t h e fungus transplant. T h e apparent inhibition points l i s t e d i n T a b l e I1 show t h a t t h e t w o distillation fractions collected between 210' and
Table
Av. Molecular Weightb
Ill. Effect of Chlorination on Toxicity Whole Creosote, Specimen I Untreated Chlorinated 199
Vacuum Fraction IIIa Untreated Chlorinated 162
0.065 0.040 AIP, wt. Yo 0.045 0.010 0.010 0.085 0.085 TIP, wt, % 0.050 KP, wt. % 0.090 0.100 0.050 0.010 'Obtained by vacuum distilling lignite creosote specimen I at absolute pressure between 8 and 15 mm. of mercury. This fraction boiled between 82' and 90°C. under these conditions. Material would be found in AWPA fractions I1 and In. bBy freezing point depression method.
270'C. a r e more toxic than t h e other fractions. However, Duncan ( 6 ) s h o w s that t h e tar a c i d s i n t h e fractions above 270'C. a r e of prime importance i n producing t h e toxicity of t h e creosote t e s t e d by her. T a b l e 111 shows t h e effect of chlorination on t h e toxicity of t h e whole creosote, and on that of o n e of t h e fractions from t h e vacuum distillation of creosote specimen I. ? h e extent of chlorination w a s estimated to b e one gram-atom of chlorine per gram-mole of creosote. T a b l e I11 shows that chlorination h a s improved t h e toxicity of fraction I11 but w a s less effective with whole creosote. Other e f f e c t s of chlorination included an i n c r e a s e in t h e specific gravity of t h e preservative; for vacuum fraction I11 from 0.991 t o 1.17. For t h e whole creosote t h e specific gravity after chlorination w a s not measured, but i s known t o exceed 1.00. Also, chlorination resulted in the formation of considerable slimy or gummy residue in t h e whole crecsote, but not in vacuum fraction 111. CHEMICAL AND ENGINEERING DATA SERIES
305
In Figure 1 t h e r e s u l t s of the evaporation t e s t for lignite creosote specimen I are compared with r e s u l t s of a similar t e s t done by Vaughan (12) on coal-tar creosote. T h e purpose of t h e s e t e s t s w a s t o obtain some i d e a of t h e probable permanence of t h e preservative. From Figure 1 lignite
CONCLUSION
T h e proper evaluation of a wood preservative requires the u s e of s e r v i c e t e s t s s u c h as l i s t e d by P r o s t e l (8) for lignite creosote. However, t h e toxicity values reported i n the present study suggest that lignite creosote should prove t o be a satisfactory wood preservative. Chlorination may enhance i t s usefulness, although m e a n s of eliminating sludge formation would have t o be investigated. ACKNOWLEDGMENT
5
LIGNITE
T h e authors are indebted t o t h e .Saskatchewan Research Council for financial a s s i s t a n c e .
CREOSOTE
I- 30-
LITERATURE CITED
COAL-TAR CREOSOTE I A F T E R VAUGHANI
5
0
Figure 1.
IO TIME
-
20
25
week8
Evaporotion curves of lignite and coal-tar creosotes
creosote may b e expected to b e less satisfactory than coaltar creosote in t h i s respect. However, volatility effects may b e offset t o a degree by a p o s s i b l e greater ease of penetration of t h e wood by l i g n i t e c r e o s o t e during impregnation.
(1) Abraham, H., “Asphalts and Allied Substances,” 5th ed., Vol. 1, pp. 381-2, Van Nostrand, New York, 1945. (2) Am. Soc. Testing Materials, ASTM Standards, Part 11, p. 597, 1946. (3) Ibid., Part IV, p. 1041, 1955. (4) Am. Wood-Preservers’ Assoc., Manual of Recommended Practice, loose-leaf, A. W.-P. A., Washington, D.C., 1951. (5) Baechler, R. H., Proc. Am. Wood-Preservers’ Assoc. 43, 94 (1947). (6) Duncan, C. G., Ibid., 48, 99 (1952). (7) Finholt, R. W., Anal. Chem. 23, 1038 (1951). (8) Prostel, E., Proc. Am. Wood-Preservers’ Assoc. 45, 62 (1949). (9) Reid, W. T., U. S. Bur. Mines Inform. Circ. 7430, 15, 22 (1948). (10) Schmitz, H., others, Ind. Erg. Chem., Anal. Ed. 2, 361 (1930). (11) Van Groenou, H. B . , Rischen, H. W. L . , Van den Berge, J., “Wood Preservation during the Last 50 Years,” pp. 179194, 204-205, A. W. Sijthoff, Leiden, 1951. (12) Vaughan, J. A,, Ind. Eng. Chem. 41, 526 (1949). Received for review July 29, 1957. Accepted February 24, 1958.
Applicability of a Specific Gravity-Oil Yield Relationship to Green River Oil Shale JOHN WARD SMITH Petroleum and Oil-Shale Experiment Station, Bureau of Mines, Laramie, Wyo.
A
specific gravity-oil yield relationship developed by the Bureau of Mines, Department of the Interior, for o i l s h a l e s of the Rifle, Colo., area (6) i s applicable t o oil s h a l e s from 10 locations in t h e P i c e a n c e Creek B a s i n of Colorado and the Uinta Basin of Utah. Average values of weight of oil s h a l e per unit volume and oil yield of oil s h a l e per unit volume based on s h a l e s p e c i f i c gravities estimated from t h i s relationship showed error limits which w e r e less than f 2.6% of corresponding v a l u e s based on determined s h a l e specific gravities. For all t h e samples included in t h i s study t h e standard deviation from determined oil yield v a l u e s of oil yields estimated from d e termined s p e c i f i c g r w i t i e s using the D-5 relationship w a s 2.0 gallons per ton. T h i s datum indicates that 95% of estimated oil yields will fall within 4 gallons per ton of t h e determined values. Nine of t h e 10 cores chosen for t h i s study w e r e from t h e P i c e a n c e Creek Rasin deposit in Garfield and Rio Rlanco Counties, Colo. One c o r e w a s from the Uinta Rasin deposit in Uintah County, Utah. T h e s e cores afford the b e s t coverage available a t present for t h e Green River formation oil s h a l e s a s a whole. To compare o i l s h a l e s of equivalent grade, s e c t i o n s of the cores having average oil yields of 25 gallons of oil per ton of s h a l e w e r e examined. T h e s e s e c t i o n s represent t h e Mahogany zone of the Green River formation, which i s comprised of t h e richest oil s h a l e s in the formation and will
306
INDUSTRIAL AND ENGINEERING CHEMISTRY
probably be t h e first portion processed commercially to liquid fuels. T h e oil s h a l e s in t h i s zone a r e commonly designated by their d i s t a n c e above and below a distinctive bed of a n a l c i t e about 4 inches thick, known a s the Mahogany marker. Geologic s t u d i e s indicate that t h e P i c e a n c e Creek Basin and the Uinta Basin w e r e once continuous, and t h e oil s h a l e s in both b a s i n s show the Mahogany marker and the Mahogany zone. T h e relationship between specific gravity and oil yield i s a consequence of the nature of oil shale. Specific gravity v a r i e s inversely and oil yield varies directly with the concentration of organic material in the shale. T h e relationship for o i l s h a l e s of the Green River formation i s not linear, because the percentage of organic material converted t o oil and the specific gravity of t h e oil change with t h e amount of organic material. However, when the s p e c i f i c gravities of the constituents of oil s h a l e s from a deposit are uniform over t h e deposit, a relationship applicable t o t h e entire deposit may b e developed (4, 5). In the previous study the compositions of oil-shale samples from two locations in the Green River formation were shown to be uniform enough t o allow development of an algebraic equation relating specific gravity t o oil yield for each of two locations (6). T h e present study demonstrates t h e applicability of one of t h e s e relationships developed for t e s t hole D-5 of t h e Rifle, Colo.,area to nine other cores and, by implication, VOL. 3, NO. 2
