T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
sogo
Vol. 9, No.
12
I
ORIGINAL PAPERS COMPARATIVE TESTS OF CHEMICAL GLASSWARE' By PERCYH. WALKERAND F . W. SMITSER Received October 23, 1917
The cutting off of imports from Germany and Austria has forced u s t o rely upon American manufacturers for practically our entire supply of glass beakers and flasks. In order t o give chemists some information as t o the quality of this ware, the Bureau of Sxandards has examined five brands of American-made ware in comparison with the two best known wares of European make. The tests included chemical analysis, determination of coefficient of expansion, refractive index, condition of strain, resistance t o repeated evaporation, to heat, and t o mechanical shock, and resistance to chemical reagents. In all cases beakers and flasks approximating in size the 400-cc. Jena beaker and flask were used. All
ers, consisted in repeated evaporation t o dryness of sodium chloride solution with examination for cracks after each evaporation. None of the wares developed cracks after twelve evaporations. One of the heat shock tests consisted in filling t h e beakers with cold water, which was then rapidly heated t o boiling. Other tests included the plunging into ice water of vessels containing boiling water, paraffin a t 150' C., and paraffin a t zoo0 C., and the dropping of beakers bottom down upon a thick board from heights increased by intervals of 5 in. The solubility tests were made by determining the loss in weight of pieces of the wares upon treatment with water and various solutions commonly used in the laboratory. With water on beakers the action was continued about 7 2 hrs., the water being heated about 24 hrs.; on flasks, t h e action was continued about 1 7 hrs., keeping the water boiling during 5
WATER
(N HJ2S t NH +CI
K
I$?* T s P
N
FL
J N F
-
Fro. I-Loss
IN
ACIDS
L
... . -.
WEIGHTOF BEAKERSWITH WATER,AMMONIA, AMMONIUM SULFIDEAND CHLORIDE, ACIDSAND SODIUMPHOSPHATE SOLUTIONS
the ware tested bore permanent trade marks. From 45 t o 5 0 beakers and flasks of each ware were secured for this series of tests. Table I gives the composition of the different wares tested. Details regarding t h e methods of analyses, weight a n d size of pieces tested, coefficient of expansion, refractive indices, and condition of strain will appear in a publication of the Bureau of Standards and are not given here, since little information bearing on the suitability of the various glasses for laboratory use can be obtained from these results. The Pyrex ware has low coefficient of expansion and refractive index. The evaporation test, which was made only on beak1 Published by permission of the Director of the Bureau of Standards. An abridgement of a lnuger and more complete publication to be issued by the Bureau of Standirrrls.
hrs. ; with mineral acids, solutions containing sodium chloride and sodium nitrate were mixed with a large
WARE
{
TABLEI-ANALYSES Kava- M. E. G . Co. Pyrex Jena Jena Nonsol Fry Libbey lier Beaker Beaker Beaker Beaker Flask Beaker Beaker Beaker 2.1 2.5 2.7 2.0 4.2 4.2 0.14 1.0 0.35 0.25 0.25 0.27 0.23 0.22 0.44 0.08 ... 7.8 3.6 10.9 10.9 5.6 ...
... .... ... PbO.. .... ... 0: 02 0.02 MnO.. ... 0.66 CaO., ., . . 8.7 0.17 4.3 MgO.. , . , 10.8 NazO.. ... 7.1 0.30 RzO.. .... 7.9 73.0 Si02 ...... 75.9 3.6 ... BzOs.. .... PzOi.. .... 0.08 ... SO8 ....... 0.20 0.02 A~,o& ..... Trace 0 . 0 2
AlzOa.. FezO:. ZnO...
...
0:01 0:01 0.29 0.63 0.06 0.21 4.4 7.5 0.20 0.37 80.5 64.7 11.8 10.9
0:61 0.56 0.25 7.8 0.31 64.7 10.6
0:01 0.79 3.4 10.9 0.30 67.3 6.2
0:03 2.6 2.6 9.8 1.5 68.6 8.1
1 .o
0.03 0.42 0.08 8.2 0.67 75.9 10.8
..................
d.'io d.*i4
0:i~ 6:i6 0.60 . . . . . . .6:ig . . Trice 0.62 . . . . . . . . . .------. TOTAL.. .. 100.29 100.27 100.21 99.81 99.79 100.05 99.93 100.00
SbrOr..
Selenium and tluorine were not found. but lithium was detected spectroscopically by Mr. Paul W. Merrill in all the samples.
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
Dec., 1917
1091
TABLB 11-HEAT AND MECHANICAL SHOCK TESTS No. refers t o Number Tested. U, Unaffected. F , Failed. b, Broken. c. Cracked Para511 Heated in Vessel to Indicated Water a t 4' C. Heated to Boiled Water and DROPTEST-BEAKERSONLY Temperature and Vessel Plunged into Ice Water Heated t o 1.50' C. Plunged into Ice Water Boiling over Direct Flame Heated t o 200° C. (6 of Each Ware Tested) BEAKERS FLASKS BEAKERS FLASKS BEAKERS FLASKS BEAKERS FLASKS No. that Broke on Drop of: Result Result Result Result Result Result Result Result 5 10 15 20 25 30 See WARE No. U. F. No. U. F. No. U. F. No. U. F. No. U. F. No. U. F. No. U. F. No. U. F. in. in. in. in. in. in. Note Kavalier... 4 1 3c 0 2 2 0 0 2 1 1 c 0 4 0 4 6 0 4 2 M.E.G.CO 2 2 o 4 ' i 2 2 o 2 . 2 ' 0 2 1 IC 4 ' i il. 4 o 4b 2 ' 0 3 3 Pyrex ............ 2 2 0 2 2 0 2 2 0 2 2 0 2 2 0 2 2 0 4 4 0 5 3 2 .. i . . i i i t ; t j Jena 2 2 0 2 2 0 2 2 0 2 2 0 2 2 0 2 2 0 4 1 3 b 4 1 3 b 2 ' 3 1 . . . . . . . Nonsol ........... 2 2 0 2 2 0 2 2 0 2 2 0 2 2 0 4 4 0 2 2 0 4 0 4 b 3 1 '2 2 2 0 2 2 0 2 2 0 4 3 1 c 4 . . 4 b Fry 2 2 0 4 3 1 c 4 0 4 b 1 2 . . 2 . . 1 Libbev ........... 2 2 0 2 2 0 2 2 0 2 2 0 4 4 0 4 4 . . 4 4 0 4 0 4 b z i . . i . . z ' ( k (m)One broke on bound a t 25 in. a n d 2 did not break a t 45 in. (n) One broke on bound a t 20 in.
...... ......
il:
...........
........
ii,
.............
.........
.............
excess of sulfuric acid, boiled and heated for an hour after fumes of SOs appeared. With sodium and potassium carbonates and hydroxides and sodium phosphate half-normal solutions were boiled for 2 0 mins. in the vessels and in t h e case of beakers fresh halfnormal solutions were subsequently evaporated in the same beakers. With ammonia, strong ammonia was allowed t o stand 24 hrs. in t h e vesse.1, then diluted a n d boiled for 30 mins. With ammonium sulfide a n d chloride, mixtures of twice normal salts were allowed t o stand in the vessels 2 4 hrs., then boiled for 30 minutes. Table I1 shows the results of heat and mechanical shock tests. Figs. I t o I V show the effects of t h e various reagents on t h e wares tested. I n these figures
;E;
P J
P
L
$k:
P
.......... .-- - - - ,.
K
J
N.
e.
.-___..*
fi. P
... ....__. . .-. - - .-
J
-
F N L '
'
L
individual accepted determinations are shown by dots, determinations which are believed t o be in error and therefore omitted from the averages b y circles. The lengths of the rectangles indicate t h e averages of accepted values. The letters K , M , P; J , N , F , and L indicate Kavalier, M. E. G. Co., Pyrex, Jena, Nonsol, Fry, and Libbey, respectively. Table I11 gives a general summary of the res'.s t ance t o the various solutions and t o mechanical and heat shock of the wares tested. I n thistable the numerical exponents indicate the minor differences in resistance, t h e lowest number being t h e most resistant. The absence of an exponent indicates t h a t t h e differences in resistances are too small t o justify any differentiation between the wares graded in the same group.
,.-
-
-.__._ +---.--. ._ - - -.__ _ _ - _ __. _.
-.
.--.
.-
..
__.
~
I
FIG.
11-LOSS
IN
1
WEIGHT O F BEAKERS WITH SODIUM CARBONATE. POTASSIUM CARBONATE, SODIUM HYDROXIDE, A N D POTASSIUM HYDROXIDE SOLUTIONS
WATER
NHr
ACIDS
BOILED NazCO,
F L
-
0
r m p -0
..................
!B
BOILED KaCO,
F
smp
I
0
1
I
S
ID
15
L
L O W
BOILED NaOH
@HS,St NH,CI
BOILED KOH
BOILED NsHPO,
L FIG.
I N WEIGHT O F FLASKS WITH WATER, ACIDS. A M M O N I U M SULFIDE A N D CHLORIDE. AND S O D I U M
111-LOSS
PHOSPHATB
SOLUTIONS
AMMONIA,
FIG. IV-Loss IN WEIGHTof FLASKS W I T H SODIVY CARBONATE. POTASSIL'M CARBONATE SODIUM I-IYDROXIDE A N D POTASSIL'M HYDkOXIDC SOI.CTI0N.S
T H E J O U 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
I092
TABLE III-GBNBRAL
SULIXARY OF
TESTS
Ammonia and CarAmmoMineral bonated Caustic nium Heat RBSISTANCB To: Water Acids Alkalies Alkalies Salts Shock Kavalier Poor Good Poor Goods Good’ Poor M . E . G.Co Goods Good Good’ Goodl Good Poor Pyrex Good’ Good Goods Fair Good Good’ Jena Good‘ Good Good* Fair Good Good: Nonsol Good: Good Goodl Fair Good Goods Good4 Good Good’ Fajr Fry Good Poor Goodl Good Goods Fair Libbey Good Good’ Far superior to any of the other wares.
......... ...... ............ ............. ........... ........... ..... ... ... ... *
Mechanical Shock
Poor
Poor Good* Fair Fair Good Good
I n the rating of resistance t o caustic alkalies the boiling tests only have been considered. These results indicate t h a t all the American-made wares tested are superior to Kavalier and equal or superior t o Jena ware for general chemical laboratory use. BUREAU OF STANDARDS WASAINGTON,
D.c.
EFFECT OF COPPER ON CRUDE RUBBER’ By
*
&AS.
P.
FOX
Manufacturers of rubber goods, following the teachings of Pearson,2 have carefully avoided the use of copper salts in their compounds. Coppered iron was used t o a limited extent in vulcanizing rubber t o iron. Copper in this operation has recently been superseded by a plating of other metals. T h e accidental observation of Dewar concerning the marked change of a rubber gasket used in contact with a copper pipe led him t o compare its action with other metals. His tests were made by covering sheet rubber with disks of metals a n d exposing them t o a heat of 150’ F. for several days. His findings were t h a t copper gave the greatest effect, a n d t h a t t h e action was due t o oxidation, copper being a n oxygen carrier. Thompson and Lewis3 took u p the matter and made a n exhaustive study of the action of metals and their salts on vulcanized rubber. Their work was with sheet rubber vulcanized by the Parkes process (cold-cured). The metals, in form of powder, were sprinkled over the surface of t h e sheet and t h e salts, if soluble in water, were made into a paste and applied as a paint. The treated sheets were then exposed for I O days a t a temperature of 60’ C. The action was determined by stretching the test piece. Their results sustained those of Dewar: “Of t h e metals used copper was by far the worst, Copper salts completely destroyed the rubber.” Foden, English textile expert, found that wherever cloth containing copper (used in dyeing) was used in water-proofing, the rubber became hardened and was soon destroyed. Weber4 gives a n explanation of the action of copper on rubber, experimental data and a method of estimating copper in cloth. This method is simple and reliable, and should replace the methods now used in determining copper, in foods. Weber places the maximum limit of copper in cloth for water-proofing a t 0.005 per cent. Weber also noted t h a t t h e presence of grease or oils in t h e cloth facilitated the action of t h e copper. 1 Presented at the 55th Meeting of the American Chemical Society, Boston, September 10 to 13, 1917. 2 “Crude Rubber and Compounding Ingredients.” I Abstract Journal, SOC.Chem. Ind., 10 (1891). 717-718. 4 “Chemistry of Rubber.”
Vol. 9, No.
12
Eschl attributes the action of copper to, the formation of copper chloride which acts as a n accelerator. Morgane states t h a t the presence of copper compounds may cause “tackiness” in crude rubber, and strongly advises against t h e use of copper vessels in the preparation of crude rubber, and even against t h e use of copper insecticides or fungicides on trees during the tapping operation. By experiments made b y riddipg copper salts t o rubber latex, Morgan concludes t h a t the rate a t which tackiness is induced is dependent upon the amount of copper salts used. The formation of resins is t h e main factor in t h e copper-induced tackiness. Schidrowitz3 says t h a t tackiness is due t o a physical degradation of the rubber molecule and not t o a change in its chemical composition. There seems t o be a distinct difference between “perished” or “decayed” rubber (Thompson and Lewis), a n d t h e “tackiness” observed by Morgan. Tackiness as understood by the practical rubberworker is a soft sticky condition affecting crude rubber. Several years ago I became interested in the action of copper on dry crude rubber. Some of these experiments have recently been repeated. I n this particular case the work shows the action of copper in the form of acetate on Pale Plantation sheet crude rubber. Small pieces of this grade of crude rubber were treated with a I per cent water solution of neutral copper acetate; copper acetate solution with I O per cent acetic acid; copper acetate solution with I O per cent ammonia; and oil carrying I per cent of dry copper acetate. Action was checked against blanks of untreated specimens, and with straight oil-treated samples. To observe the action of light two series were run, one ( A ) being exposed t o bright light in a warm room, and the other ( B ) placed in a cool and dark closet. Extremes in a p p l i c a t i o n of the chemical are represented by a single spot, and by i m m e r s i o n for 24 hours. Duration of experiment was approximately 3 months. Each set consisted of six pieces. The original test pieces were mounted on cardboard. These cards were unavoidably lost in transit, preventing their reproduction, and a written description is substituted herewith. Each series was subdivided into two subdivisions: No. I. DROP TEST-One drop of reagent was allowed t o dry on the surface of t h e specimen. No. 11. IMMERSION TEsT-The entire specimen was immersed in the reagent for 2 4 hrs., then dried. The “spot test” gave tackiness a t point of contact between reagent and the rubber. The “immersion test” gave tackiness over the entire surface of the specimen. With the oil experiments even a single drop was too much, while those immersed were ruined (the specimens softened and “run”). All t h e treated samples showed tackiness due t o the reagent. The ammonia copper acetate combination shows a much greater action t h a n copper acetate alone or in combination with acetic acid. The oil1 “Manufacture 2 6
of Rubber Goods.“ “Preparation of Plantation Rubber.” “Rubber.”
