747 Percentage 01 total iron occurring as temp. of Fe Metal- Fer- F?riurion Per lie f0"S .r*c Iron nron 0 C. cent iron 6 94 Trace 1280 4.7
Maximum Total
IAB.
hTo DBSCPIiPTrON 15848) Ash fused in atmosphere of SO% hydrosen : 50% water YhPOT. 16243 ih243 Ash fused in atmosphere of hydrogen. 36243 Ash fused in atmosphere of water vapor. 13629 Ash fused in atmosphere of air. 20137 Clinker f m m a hand-tired furnace. 20145 Clinker from a boiler furnace equipped with Roney stoker. 20th Street sintion. 204.52 Ilitto, Brunof's Island station.
i
1
( 1080 1370
1300 1400
..
.. ..
27.4 28.6 27.9 I S .S
GnalE or'
Not magnetic.
82 21
18 I 72
Trace 12
79
70 9
Dark red to ahnost black. glarny. highly, magnetic. Dark gloss: some piece3 slightly magnetic.
75 75
16
19
Brown t o black glass: some pieces slightly mr~nelic. Black glass, slightly mametic.
14.5
12.7 8.9
6 9
--FHOM
Color
Tncc 78 Trace
some taffy-like variety t h a t flow over t h e grat,e bars a n d s h u t off t b e air suppiy for combustion. Fig. 8 is a photograph of clinker z o 4 j z . T h e straight-line edge is t h e side which adhered t o t h e corrugated grate of t h e new model t y p e 1) Roney stoker. T h e matrix of this clinker was a black glass which could be readiiy chipped o u t in q u a n t i t y for analysis without including a n y piece of cokc or unfuscd material. ,4t t h e contact surface of coke a n d slag, particles of metallic iron coul(j be iilentified. A microscopic examination ol t h e powd e r r d sla,g from this ciinker a s well a s from t h e others, b y MI. A . A . Klcin of t h e Bureau of Standards, s h o x e d t h e material t o lx: essentially a riass with sillimanite
Fir; ~ . - - - C L ~ N A.0. X ~ K20.452
os_SLAC Not magnetic.
CH***CTEL
1.1glii-groy
ROSBU STc~aEii
I
28 30
Glairy black.
Bisck,mcialliclu~tter:containedmrgneticpartieles of metalliciron. CIlasry black. suitace had reddish tint; strongly magnetic.
hydrogen and water vapor, ranging f r o m io0 per cent hydrogen t o 100 per cent water vapor. 11-These results piotted in t h e form of curves showed t h a t for each of t h e ashes tested, there was a high softening temperature in pure hydrogen on one end, due t o reduction of iron oxide t o metallic iron; a similar high softening' temperature in water vapor or air on t h c other end, due t o t h e iron oxide remaining for the most p a r t in t h e form of ferric iron or magnetite; and a more or less lower softening temperature in t h e middle portion ranging f r o m 3 0 t o 70 per cent water vapor, due t o t h e reduction of iron t o t h e ferrous s t a t e in which i t combined t o form the readilv fusible ferrous silicates. 111-Analyses of actual clinkcr slags from t w o different boiier furnaces a n d one experimental furnace showed t h a t fuel-hcd conditions are such as t o favor tlie iormation of clinkers containing iron principally in t h e ferrous state. IT'---A new method oi determining t h e minimiim softening temperature of coal ;ish has been devised, in which t h e ash is heated i n a n atmosphere of approximatcly j o per cent hydrogen and j o per cent mater vapor, whereby t h e iron oxide is caused t o combine principally in t h e ferrous s t a t e , as actuaily found in fuel-bed clinkers. ACLKOWLSDGIEN'TS
(A1103, SiOl) as t h e oniy crystalline phase present, T h e authors t a k e pleasure in acknowledging their exceptsampic 2 o r 3 7 wllici, aiso co,ltained Bn opaque indebtedness t o Dr. G. 4 . Hulett, chief consulting iron mineral, probably magnetite. chemist, for many heipful suggestions a n d criticisms; I, comparison of analyses of the fused ash cones, and of t h e fucl.hed clinkers gi-i.en in ~ ~ 17, b t o A. l E.~ Hall for assistance in building t h e furnace a n d sho.rvsthat of the (lificrent in t h e in t a k i n g t h e preliminary observations; and t o H . N. Hill for t h c careful analysis of t h e slags a n d clinkers. iaijorzitory furnace, jo : jo per cent i,ydrogcnC I I T M ~ C A LI,*BORATOBY,R u n Z ~ i OF i MzNBJ water vapor mixture produced a slag which corrcFllTS.IIRCII. P A . sponded most closely in t h e s t a t e of oxidation of its iron . content t o t h e glassy portions of t h e furnace clinkers. In both cases approximately 8 0 per cent of t h e iron PONTiANAK (JELLUTONG) RUBBER RESIN ny C I ~ I . E I O N Z L L ~AND A. A. WT.LI.S appeared as ferrous iron, t h e f o r m in which it imparts Reccivcd April I?. 1915 the maximum fluxing action on t h e silicate mixture. Wc m a y , thcrefore, conclude t h a t t h e minimum softPontianak ox Jellutong rubber resin has appeared eiiing temperature of a coal ash, a s determined in a jo : 50 o n t h e market in relatively large quantities during t h e per cent atmosphere of hydrogcn and water vapor, is past few years a n d no little effort has been made t o more representative of t h e temperature of clinker find profitable outlets lor this material. A t t h e formation under furnace conditions t h a n t h e more or present time, for various reasons, t h e available supply less higher results obtained in strongly reducing atmos- of t h e resin has been much reduced. pheres of hydrogen, or carbon monoxide, on t h e one Jellutong is obtained l a g e l y f r o m Sarawak, Dutch h a n d , a n d oxidizing atmospheres of air, water vapor Borneo, S u m a t r a a n d t h e Maiaysian Peninsuia. T h e or carbon dioxidc on t h e other. product from S a r a v a k was t h e first t o be termed S U Id H A R Y Pontianak a n d t h e name subsequently was applied t o I-Softening temperatures of five diffcrent coal substantially similar products f r o m t h e other localities ashes have been determined in various mixtures of mentioned.
748
T H E J O C R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
Vol. 7 , No. 9
For a time the ‘rubber manufacturing industries did t o collect the former so t h a t while the’ acetic acid and not look with favor upon this material b u t later it other relatively volatile bodies were removed as fast won for itself the place which it now holds. as formed, t h e oils were constantly returned t o the I n round numbers we may say t h a t Jellutong con- retort. It will be noted from the table t h a t after tains I O per cent rubber, 20 per cent resin and 7 0 per the resin is once heated well above the melting point cent moisture, etc. The process of purification of t h e the temperature a t which it again fuses is lowered. crude gum involves extraction with acetone or similar This tendency seems t o continue until, when the solvents t o remove t h e resin. The resinous product temperature is raised t o about 3 4 3 ’ C., destructive thus obtained appears in commerce usually as white distillation proceeds rapidly and eventually the mass or yellowish, friable, lumpy masses carrying a variable (using reflux condenser) becomes plastic and flowable amount of moisture. I t vias supposed a t first t h a t a t ordinary room temperature, and finally, on raising the resin would serve as a substitute for ordinary the temperature still higher, light and heavy oils come rosin and other resins. The properties of Pontianak 01-er. This oily material was freed from acetic acid rubber resin, however, prox-ed t o be such as t o restrict and then redistilled and fractionated, affording a its fields of application, and t o such an extent t h a t for series of light colored oils of an unsaponifiable a time t h e resin was regarded almost as a waste material. character. I n this connection attention is called t o a discussion A sample of the crude resin ?lo. 2728 was examined of t h e subject b y H . 0. Chute.’ Statistics on t h e for unsaponifiable matter b y heating with alcoholic Pontianak rubber industry are given by Schidrowitz.2 potash, diluting with water and extracting the unsaponiD a t a on the composition and characteristics of the fiable bodies with benzol. The results showed an resin have been furnished b y Hinrichsen and Mar- average of about 9 5 per cent unsaponifiable matter. cusson3 and Dubosc.* The last-named investigator TABU?I-EFFECT O F HEATO N POSTIANAK RUBBERRESIS notes the dissimilarity of this resin with the ordinary Loss Fusing Hours Temp. Per point resins of commerce and hints for the acetone-soluble hTo. heated C . cent C. REMARK5 resin a constitution of a hydroxy nature, similar t o 2728 None .. . 0 126 White powder 2977 77 Hard and clear 12 205 3.1 cholester 01. 2991 10 232 .5,9 78 Hard and clear 2974 9 264 13.1 Hard and clear ! I ! The resistance of Pontianak resin t o the action of 1 316 2847 Hard a n d clear 3369C 3’:s 343 50 . . . H a r d and clear aqueous alkali solutions has led t o its application as 3369D 5 343 10 65 Hard and clear 3369E 4 343 16 Plastic a coating material for cement and c0ncrete.j I t has 3369F 6 343 18 Very plastic, flowable 3360 Destructive distil!ation . Oil also been proposed t o use the resin in making paper sizing.6 The volatile oils resulting from the deApart from the formation of acetic and other volatile structive distillation of rubber resins have been sugacids, heat treatment appears t o increase the proportion gested as a raw material for preparing isoprene. of unsaponifiable bodies. I n searching for new uses for the resin we have had The iodine value generally shows a n increase on occasion t o carry out a large number of tests of various kinds t o determine its properties. The results of some heating the resin. A sample of t h e crude resin afforded a n iodine number of 36, while No. 3369F gave a value of these tests are given in the tabulations below. of 62 and the oil obtained b y destructive distillation E X P E R I ME K T hL (freed of u-ater-soluble acids) exhibited a; iodine D E S C R I P T I O N O F SAbIPLEs-The samples O f resin number of 93. By the addition of small amounts of employed in this investigation were selected with refer- oil-soluble manganese compounds t o these oils or ence t o t h e heat treatment they had received, and t o soft plastics rather marked siccative properties were the characteristics they exhibited when placed in manifested. solution. As some attention has been directed towards PonI n Table I, we have tabulated certain of the changes tianak rubber resin as a promising material in the taking place on heating Pontianak resin under various preparation of varnishes and paint oils and as conconditions. K O . 2728 is the crude resin obtained siderable disappointment has arisen because of lack from the extraction process free of moisture: 2977, of knowledge of the solubility phenomena of this resin, 2991, 2974, 2 8 4 j and 3369C were heated in open Table I1 details a t some length the behavior of t h e vessels. In the case of 33690 a water-cooled reflux resin in a number of the solvents commonly used in condenser was used, thus returning t o the retort all the varnish and paint industry. X s a practical conthe condensable products of distillation. Xos. 3369E sideration. high-grade commercial solvents were used and F were heated in a retort having a short air-cooled in preference t o chemically pure ones. The numerical reflux condenser t o permit the escape of acetic acid and data involve the use of customary U. S. weights and similar relatively volatile bodies while retaining the measures in order t o be more readily available t o the oily bodies formed. A water-cooled condenser served varnish maker. 1 India Rubber W o r l d , July, 1909. 2 I b i d . , Dec., 1911. Commercial 90 per cent benzol, “commercially” 3 Z. angew. Chem., 24, 7 2 5 . pure spirits of turpentine, light benzine or “varnish 4 Caout. et Gultapercha, 8 , 5756. makers’ naphtha,” heavy benzine and solvent naphtha 6 I n d i a Rubber W o r l d , Nov., 1911: also U. S. Patents 999.493 and 999,708 of Aug. 1, 1911, 1,005,818 of Oct. 1 7 , 1911, and 1,006,73i of Oct. were selected particularly because of their general use 24, 1911. in varnish making. The heavy benzine employed was a a The Paper Mill and W o o d Pulp Kews, Dec. 2, 1911; also U. S. P a t e n t commercial petroleum hydrocarbon solvent, having 1,007,681 of Nov. 7, 1911. i i
Sept., 1 9 1 j
T H E JOC;RIVAL O F I A - D U S T R I A L A N D ENGI,VEERING C H E M I S T R Y
a flash point of about 110' F., commonly used as a substitute for spirits of turpentine. Most of t h e samples detailed in Table I1 had been made u p from one t o two years. By ageing in this manner, very exact results could be obtained as t o the permanent character of t h e solution. Solutions which mere not permanent when first made up, gradually threw down a portion of t h e resin until a stable solution was obtained. Thus we note t h a t in more t h a n half t h e samples, some resin, varying from a few flocculated particles t o a percentage large enough
749
equal, in a rough way, indicated the relative amount of resin in true solution. I n determining t h e percentage of resin in t h e supernatant liquid. weighed amounts of the solution were dried t o constant weight. One of t h e interesting features of Table I1 is t h a t relating t o t h e condition of thin films of the solutions when allowed t o dry on glass plates. I n a great many cases frosted slow-drying films were obtained. I t will be noted t h a t these were usually formed wherever t h e percentage of solid material in the containers was greatest, although there are exceptions. Sample K O .
TABLE 11-BEHAVIOR O F P O N T I A S A K RUBBERRESIN III' HIGH-GRADECOMMERCIAL SOLVENTS A-0. 2728-Crude Pontianak resin melted and thinned with solvents. A-0. 2 9 i P F u s e d Pontianak resin heated t o 264' C. for 9 hrs. and No. 2 8 2 6 F u s e d Pontianak resin melted and thinned mith solvents. thinned with solvents. No. 2775-Crude resin melted and thinned with solvents. S o . 2832-Pontianak resin heated t o 264' C. for 1 hr. and thinned with N O . 3028--.4 and B-dry fused Pontianak resin melted and thinned. solvents. C-Crude resin pulverized t o pass 40 mesh, benzol added and h*o. 2847-Pontianak resin (light yellow color) heated t o 316O C. for I,', shaken in t h e cold until dissolved. hr. and thinned with solvents. N O . 2813-Crude No. 2822-Pontianak resin heated t o 320° C. and thinned with solvents. resin melted and thinned with solvents. h'o. 2977-Fused resin heated t o 204' C. for 12 hrs. and thinned with A-0, 3369-D-Pontianak resin heated 5 hrs. a t about 343O C. with a water-cooled reflux condenser. solvents. h-o 2991-Fused Pontianak resin heated t o 232' C. for 10 hrs. and E-Resin heated 4 hrs. same a s above except air-cooled reflux. thinned with solvents. F-Same a s E except heated 6 hrs. Resin SAME (COMMERCIAL) AND AMOUNTOF SOLVENT USED COKDITIONPer cent resin RESIDUE FILM OF used in clear AFTER ON TurpenHeavy Solvent BenLight Pio. tine benzine naphtha zol benzine SOLUTION solution 02. EVAPORATION GLASS 2728 1511% 24 fl. 0 2 24 fl. oz. ...... 70% solid Granular Frosted 52(a) Solid 2826.4 2 2 fl. 02. ...... ...... ...... .. ...... Frosted B ...... Almost solid 2 3 fl. 0 2 . ...... ...... ...... Clear 2 Clear Clear 4 A. oz. ...... ...... ...... ...... 40% solid 38 1 fl. oz. 1 fl. 02. ...... ...... ...... ..... Almost clear 2 Solid l? Clear Frosted 2 . . . ..... 8 0 7 solid 1 fl. oz. 2 fl. 0 2 . ..... 40 F ...... Light: clear Frosted 2 1 fl. 0 2 . 3 fl. 0 2 . ...... ...... 6 5 g solid 35 46 2 775.4 4 .... ...... 4 fl. 0 2 . , .. ...... 90% solid Almost clear Frosted B 4 8 A. 0 2 . ...... Clear: granular specks Clear 29 ...... ...... ...... 5%solid 38 3028A 1 ...... . . . . ... 1 fl. 0 2 . ... Clear Clear All liquid B 1 1 A. oz. All liquid 39 ...... ...... ..... ...... Clear Clear 37 Clear Clear C I ...... ...... ...... 1 fl. oz ...... All liquid 28134 4 ..,.. ...... ...... 4 fl. 02. 2 fl. 02. Almost clear 46 Frosted Frosted B ...... Frosted 4 ...... ...... 4 fl. 02. 1 fl. oz. 1 5 % solid 5 2 ~ Granular 2977A 2 . . . ...... . . . . 2 fl. oz. D a r k ; clear Frosted ...... 90% solid 59 7 B ..... . . ..... 3 fl. 02. ...... All liquid 50 Mottled: dark Frosted C ...... ..... ...... ...... 3 fl. 0 2 . 2 D a r k ; clear 5 0 % solid 43 Frosted D ..... ...... . . . ...... 4 fl. 02. 41 5YC solid D a r k ; clear Frosted E 2 ...... 3 02. . . . ...... ...... 5 7csolid D a r k ; clear Clear 42 Almost clear F 2 ...... 4 oz. . . . . . ...... ...... 2Yc solid 3; Dark; clear 2991A 2 . . . . . ...... ..... 3 0. oz. All liquid ...... 49 D a r k : almost clear Clear B 2 ..... ..... ..... ..... 3 fl. oz. 2v0 solid 44 Dark: clear Clear C 2 . . . . . . . .. . . 4 fl. 0 2 . 2 solid 40 Mottled Clear 7 D . . . . 3 fl. 0 2 . ...... . . . . . ..... 570 solid 42 Dark: clear Clear 7 E ...... 4 fl. 0 2 . ..... ...... ..... 2 % solid 39 Dark: almost clear Clear 2974A 2 .... . . . . 3 fl. O L . ..... ...... All liquid 48 D a r k ; clear Clear R ...... ..... ...... 4 fl. 0 2 . ...... 41 All liquid Dark; clear Clear 7 ...... . . . . . ...... .5 fl. oz. ...... 36 All liquid Dark: clear Clear D 2 ..... ..... ..... 40 ..... 4 8. 02. 2 % solid D a r k ; clear Clear 7 E ...... ...... ...... , , . 5 fl. 0 2 .411 liquid 3i Dark: clear Clear F 2 .. 4 oz. ..... ..... Dark: clear 20% solid 38 Clear 2832.4 1 .... 1 fl. 0 2 . ..... 9 5 % solid .. ...... Frosted B 1 .... . . . . . 1 1 2 fl. 0 2 . ...... ...... 40y0 solid 42 Mottled Frosted c 1 2 OZ ..... . . . . Frosted ...... 607, solid 33 Clear n 1 . . . . . . . . . .... 2 oz. SOYc solid 36 Clear Frosted E 1 , . I 02. ... 1 oz. 55% solid D a r k ; clear Frosted 36 284;A 1 . . . . . . . . ..... . . . . 2 fl. 0 2 . Clear 10% solid 39 Clear B 1 . . . . 1 A. o z . ..... Clear Clear 56 D a r k : clear c 1 . . . 2 B . oz. ...... ...... ...... 5 % solid 37 Clear Clear D I 1 fl oz. 20 % solid ... 1 A. 0 2 . D a r k ; clear 38 Clear 1 2822.1 .. . . 1 fl. 0 2 . . . ..... All liquid D a r k ; clear 54 Clear I3 I I 02 All liquid . . . . . Clear ...... 45 D a r k ; clear I C Solid . . . . . 1' 2 f l 0 2 . . . ...... Clear ........ I1 I All liquid 2 fl. 02. Clear ..... 45 Dark; clear 1: I ...... . ,.. ..... All liquid Dark: clear 2 02. 40 Clear F 1 ! :02. 1 02. 1 '? oz. All liouid ...... Clear D a r k ; clear 38 33690 3 .. 5 ' ' 4 oz. ...... . . . . ...... 411 liquid D a r k ; clear 53 Light; clear E 10 . . . Equal vol. ...... . . . . . ...... All liquid 58 Dark: opaque Dark: clear F in ...... Equal vol. ...... ..... ...... All liquid Dark: opaque 56 D a r k ; clear ( a ) As the residue after evaporation was somewhat plastic. and had t h e odor of benzine, evidently some of the solvent had been retained, thus making 5 2 per cent too high,
c n
v0
c
t o make t h e entire contents of the container solid, was not in true solution. From Table 11 it will be observed t h a t there are a t least t w o factors on which depend t h e amount of resin held in permanent solution: ( I ) , t h e nature of solvent used and ( z ) , the heat treatment of the resin. I n general we may say t h a t benzol is t h e most active solvent. while benzine is t h e weakest. A good idea of the values of different solvents was obtained b y examining t h e condition of the liquids in t h e containers. T h e percentage of solid matter. other things being
33690, although the percentage of resin is j 8 as a maximum, does not show t h e maximum amount which can, with this treatment, be placed in solution. As a matter of fact, t h e plastic resin can be added t o a solvent in a n y quantities and still not form a precipitate on standing. I n Table 111, we have tried t o classify t h e solubilities with reference both t o the heat treatment a n d the solvents employed, thus making t h e whole scheme more comprehensive. T h e effect on t h e solubility of t h e length of time of heat treatment as well as t h e
T H E J O U R N A L OF I N D U S T R I A L AiVD E N G I N E E R I K G C H E M I S T R Y
7 50
Vol. 7 , NO. 9
temperatures employed are here concisely shown. For example, Yo. 2 9 7 7 is more soluble in benzol t h a n No. 2847, although heated at a temperature lower b y over 100' C., b u t on t h e other hand being heated 11 hours longer. The same is true of Nos. 3369 and 2 8 2 2 , using heavy benzine as solvent, in t h e proportion of one part solvent t o one part resin. R i t h two parts solvent t o one part resin, we see t h a t 204' for I z hours,
saturated bodies. Temperatures above 6 j o o F. exert a marked influence both as t o solubility and chemical and physical properties. 111-Pontianak rubber resin is very inert to alkalies and, practically speaking, may be regarded as substantially unsaponifiable.
TABLE 111-SOLUBILITIESOF P O ~ T I A ~ RUBBER A K RESIKWITH RBFEREXCE TO TREATMENT 4 . r ' ~ SOLVENT USED
THE QUANTITY OF GASOLINE NECESSARY TO PRODUCE EXPLOSIVE MIXTURES IN SEWERS
P E R C E N T OF
RESINI N
C L E A R SOLUTIOX
MONTCLAIR. N E W JERSEY
By G. A . BURRELL ATD
No. N o . No. N o . No. No. No. N o . 2728 2977 2991 2974 2832 2847 2822 3369 SOLVEXTS AND PARTS
USEDI N EACHCAS= TO 1 P A R T OF RESIN
. , . 38 .. . . . . . . .. . . . . . . .. . . . . . . .. . . . . . .. . . . . . . .. . . . . . . .. . . . . . .
..
..
.. .. .. .. .. 1
..
..
1'/2
2
..
.. .. .. ..
.. 1
..
11/z
2
...... . . . . .
1
.. .. ..
'/Z
49
43
44
, ,
41
40
. . . .
40 3i
36
39
40
..
42 37
42 39
38
3i
3i
45
::
. . . . . . . .
... ...... . . . 29
...
. . . . . . . . . . . . . . . . . .. ,, .. ,,
. . . . . . . . . . . . '54 . . 42 . . . .
The Bureau of Mines and the City of Pittsburgh are cooperating in an endeavor t o determine the causes of explosions in sewers and means for their prevention. The results of the investigation are being published in reports of the Bureau of Mines. I n this report are shown the quantities of gasoline which must be introduced into sewers in order t o produce explosive mixtures of gasoline vapor and air under certain conditions. hiany different conditions affect this quantity, such as size of t h e sewer, velocity of t h e sewage, temperature of the sewer air, volatility of the gasoline, rate of inflow of the gasoline, etc., so t h a t only under identical conditions of tests are duplicate results obtained.
. . . . . . . .
E XPE R I J I E N T A L
. . . . . . . . . , .. , . , , . . . . 38 . . . . 36 . . , .
The particular sewer wherein the tests here recorded were conducted is one of the largest of t h e Pittsburgh sewers. I t is 8 ft. 3 in. wide and 8 f t . 6 in. high. I n Fig. I is shown a plan of the sewer, with conditions such as existed when the first test was conducted on September 3 0 , 1 9 1 4 . At the points I , 2 , 3 , 4 , j and 6 are shown the manholes where samples of gas were collected. The distance from No. I manhole, where the gasoline was dumped into t h e sewer, t o the sewer outlet, the Allegheny River, is 2706 feet. The distance between the different manholes is marked on the diagram. The velocity of the sewer was established as follows: Pine floats 6 in. square were dropped into the upper manhole No. I a t a given signal. Stop-watches were set a t the same instant, and as the floats passed each succeeding manhole (which fact was determined by a man standing a t the foot of a ladder in each manhole) the time was caught on a stop-watch. As a result of these tests it was established t h a t the average velocity of the sewer was 6 . 4 j linear f e e t per second. The depth of the flow was about 8 in. The amount of flow was 19.6 cu. f t . per second and t h e grade of the sewer 0.90 per cent. The temperature of the water in the sewer was 21' C. (69.8' F.). The temperature of the air just above the water was 20.3' C. ( 6 8 . j 4 ' F.), and of the air above ground 20' C. ( 6 8 " F . ) .
. . . . . . . .
.,
1/2
41 36
. . . . . . . . . . . . . . . . . . 45 58
38 46
2
. 52(a) . . . 46 .. . , . 52(a) 1 .. . . . . . . .. 1 ... 1 . . ' / z 40,. . . 1/2 35 11/2 ..
. . . . . . 56 . . . . 48 . . . . . . . .
59 50
H.T. BOYD
Received June 4, 1 9 1 5
. . . . . . . . . .
. . . . . . . . . . . . . . . . . . 38
( a ) Upon evaporation, the residue was very granular and had the odor
of benzine, hence it 1s very probable that some solvent was still in the resin, thus making these results too high.
232' for I O hours, 264' for 9 hours, and 3 1 6 ' for hour give practically t h e same results, while heating t o 2 6 4 " for I hour affords a degree of solubility less t h a n any of these. On heating t o 321'. however, t h e greatest amount of resin was in solution. The mixtures of various solvents did not in many cases seem t o be more active t h a n each one taken separately. The influence of alkali on the plastic resin in thin layers is shown by the following: Samples, made u p of equal parts of plastic resin and heavy benzine and in some cases with additions of I O t o 2 0 per cent of various saponifiable siccative oil, were flowed in thin layers on glass plates and allowed t o dry for several days. The plates were then immersed in an aqueous 5 per cent caustic soda solution for j days. Upon removing the plates and rinsing, the samples containing 2 0 per cent of drying oil were found quite badly decomposed, those containing I O per cent were only slightly affected, while those containing only the dried plastic resin were scarcely softened, the resin when again dried, being in apparently as good condition as before the test.
TEST K O .
CONCLUSIOXS
I-Of t h e solvents or thinners commonly used in varnish and paint oil making, benzol is the most energetic on Pontianak rubber resin. 11-Heating the resin for an extended period makes it more soluble and increases the proportion of un-
I
At 2 . 1 0 P.M.: j j gallons of refinery gasoline, sp. gr. 6 7 . j ' BaumC, were rapidly dumped from an open barrel into t h e sewer a t manhole N o . I , by turning the barrel on end, allowing the gasoline t o run in all a t once. 1
Published with the permission of the Director of the Bureau of Mines
